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Yang M.,CAS Research Center for Eco Environmental Sciences | Zheng S.,Beijing Normal University
Biomass and Bioenergy | Year: 2014

Microbial single-cell-protein (SCP) production from high-organic-strength industrial wastewaters is considered an attractive method for both wastewater purification and resource utilization. In the last two decades, pollutant removal-oriented yeast SCP production processes, i.e., yeast treatment processes, have attracted a great deal of attention from a variety of research groups worldwide. Different from conventional SCP production processes, yeast treatment processes are characterized by higher pollutant removal rates, lower production costs, highly adaptive yeast isolates from nature, no excess nutrient supplements, and are performed under non-sterile conditions. Furthermore, yeast treatment processes are similar to bacteria-dominated conventional activated sludge processes, which offer more choices for yeast SCP production and industrial wastewater treatment. This review discusses why highly adaptive yeast species isolated from nature are used in the yeast treatment process rather than commercial SCP producers. It also describes the application of yeast treatment processes for treating high-carboxyhydrate, oil-rich and high-salinity industrial wastewater, focusing primarily on high-strength biodegradable organic substances, which usually account for the major fraction of biochemical oxygen demand. Also discussed is the biodegradation of xenobiotics, such as color (including dye and pigment) and toxic substances (including phenols, chlorophenols, polycyclic aromatic hydrocarbons, etc.), present in industrial wastewater. Based on molecular information of yeast community structures and their regulation in yeast treatment systems, we also discuss how to maintain efficient yeast species in yeast biomass and how to control bacterial and mold proliferation in yeast treatment systems. © 2014 Elsevier Ltd.


Su M.,CAS Research Center for Eco Environmental Sciences | Gaget V.,South Australia Water Corporation | Gaget V.,University of Adelaide | Giglio S.,South Australia Water Corporation | And 3 more authors.
Water Research | Year: 2013

Geosmin has often been associated with off-flavor problems in drinking water with Anabaena sp. as the major producer. Rapid on-site detection of geosmin-producers as well as geosmin is important for a timely management response to potential off-flavor events. In this study, quantitative polymerase chain reaction (qPCR) methods were developed to detect the levels of Anabaena sp. and geosmin, respectively, by designing two PCR primer sets to quantify the rpoC1 gene (ARG) and geosmin synthase one (GSG) in Anabaena sp. in freshwater systems. The ARG density determined by qPCR assay is highly related to microscopic cell count (r2=0.726, p<0.001), and the limit of detection (LOD) and limit of quantification (LOQ) of the qPCR method were 0.02pg and 0.2pg of DNA, respectively. At the same time, the relationship between geosmin concentrations measured by gas chromatography-mass spectrometry (GC-MS) and GSG copies was also established (r2=0.742, p<0.001) with similar LOD and LOQ values. Using the two qPCR protocols, we succeeded in measuring different levels of ARG and GSG copies in different freshwater systems with high incidence environmental substrata and diverse ecological conditions, showing that the methods developed could be applied for environmental monitoring. Moreover, comparing to the microscopic count and GC-MS analytical methods, the qPCR methods can reduce the time-to-results from several days to a few hours and require considerably less traditional algal identification and taxonomic expertise. © 2013 Elsevier Ltd.


Recknagel F.,University of Adelaide | Ostrovsky I.,Israel Oceanographic And Limnological Research | Cao H.,University of Adelaide | Zohary T.,Israel Oceanographic And Limnological Research | Zhang X.,CAS Research Center for Eco Environmental Sciences
Ecological Modelling | Year: 2013

The hybrid evolutionary algorithm (HEA) was implemented to model and analyze population dynamics of the different phytoplankton phyla (chlorophyta, bacillariophyta, cyanophyta and dinophyta) in relation to physical, chemical, and biological determinants and their combinations in a large lake. Biweekly measurements over a 12-year period were used as input. The validation of models obtained with HEA showed the best results for bacillariophyta and dinophyta resulting in coefficients of determination (r2) between the modeled and measured data of 0.54-0.79 and 0.29-0.76 for these phyla, respectively, suggesting good predictability of their dynamics. The lowest adequacy of HEA models was found for cyanophyta (r2 of 0.28-0.46). Models that combined physical, chemical and biological inputs scored highest, whilst zooplankton-based models scored lowest in all experiments and indicated that top-down control of algal biomass could have only secondary effect. The input sensitivity analysis was used for testing the best phytoplankton models with threshold values determining high or low algal biomass and inhibitory-excitatory effects of specific parameters. Wavelets were tested to analyze two extreme cases of dinophyta dynamics in years of its exceptionally high and low developments to gain insights into lag times between the exert of key factor and algae response. Lag times extracted from daily interpolated data of highly correlated inputs of dinophyta in 1998 varied between 2 and 4 days. © 2013.


Zhao W.W.,Beijing Normal University | Fu B.J.,CAS Research Center for Eco Environmental Sciences | Chen L.D.,CAS Research Center for Eco Environmental Sciences
Hydrology and Earth System Sciences | Year: 2012

Land use and land cover are most important in quantifying soil erosion. Based on the C-factor of the popular soil erosion model, Revised Universal Soil Loss Equation (RUSLE) and a scale-pattern-process theory in landscape ecology, we proposed a multi-scale soil loss evaluation index (SL) to evaluate the effects of land use patterns on soil erosion. We examined the advantages and shortcomings of SL for small watershed (SL sw) by comparing to the C-factor used in RUSLE. We used the Yanhe watershed located on China's Loess Plateau as a case study to demonstrate the utilities of SL sw. The SL sw calculation involves the delineations of the drainage network and sub-watershed boundaries, the calculations of soil loss horizontal distance index, the soil loss vertical distance index, slope steepness, rainfall-runoff erosivity, soil erodibility, and cover and management practice. We used several extensions within the geographic information system (GIS), and AVSWAT2000 hydrological model to derive all the required GIS layers. We compared the SL sw with the C-factor to identify spatial patterns to understand the causes for the differences. The SL sw values for the Yanhe watershed are in the range of 0.15 to 0.45, and there are 593 sub-watersheds with SL sw values that are lower than the Cfactor values (LOW) and 227 sub-watersheds with SL sw values higher than the C-factor values (HIGH). The HIGH area have greater rainfall-runoff erosivity than LOW area for all land use types. The cultivated land is located on the steeper slope or is closer to the drainage network in the horizontal direction in HIGH area in comparison to LOW area. The results imply that SL sw can be used to identify the effect of land use distribution on soil loss, whereas the C-factor has less power to do it. Both HIGH and LOW areas have similar soil erodibility values for all land use types. The average vertical distances of forest land and sparse forest land to the drainage network are shorter in LOWarea than that in HIGH area. Other land use types have shorter average vertical distances in HIGH area than that LOW area. SL sw has advantages over C-factor in its ability to specify the subwatersheds that require the land use patterns optimization by adjusting the locations of land uses to minimize soil loss. © 2012 Author(s). CC Attribution 3.0 License.


Feng X.M.,CAS Research Center for Eco Environmental Sciences | Sun G.,U.S. Department of Agriculture | Fu B.J.,CAS Research Center for Eco Environmental Sciences | Su C.H.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Hydrology and Earth System Sciences | Year: 2012

The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability and hydrologic processes at the large scale. The objective of this study was to explore ways to examine the spatial and temporal effects of a large ecological restoration project on water yield across the Loess Plateau region in northern China. We estimated annual water yield as the difference between precipitation input and modelled actual evapotranspiration (ET) output. We constructed a monthly ET model using published ET data derived from eddy flux measurements and watershed streamflow data. We validated the ET models at a watershed and regional levels. The model was then applied to examine regional water yield under land cover change and climatic variability during the implementation of the Grain-for-Green (GFG) project during 1999-2007. We found that water yield in 38% of the Loess Plateau area might have decreased (1-48 mm per year) as a result of land cover change alone. However, combined with climatic variability, 37% of the study area might have seen a decrease in water yield with a range of 1-54 mm per year, and 35% of the study area might have seen an increase with a range of 1-10 mm per year. Across the study region, climate variability masked or strengthened the water yield response to vegetation restoration. The absolute annual water yield change due to vegetation restoration varied with precipitation regimes with the highest in wet years, but the relative water yield changes were most pronounced in dry years. We concluded that the effects of land cover change associated with ecological restoration varied greatly over time and space and were strongly influenced by climatic variability in the arid region. The current regional vegetation restoration projects have variable effects on local water resources across the region. Land management planning must consider the influences of spatial climate variability and long-term climate change on water yield to be more effective for achieving environmental sustainability. © Author(s) 2012.


Mller B.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Berg M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Pernet-Coudrier B.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Qi W.,CAS Research Center for Eco Environmental Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences
Global Biogeochemical Cycles | Year: 2012

The Yangtze is the largest river in Asia and its water composition reflects the activities of about 400 Mio people in its catchment. Its chemical loads have a large impact on the biogeochemistry of the East China Sea. We discuss and quantify the annual dynamics of major ions, nutrients, and trace elements from samples collected monthly at Datong Station from May 2009 to June 2010. The Yangtze today carries 192 × 106 tons of total dissolved solids annually to the East China Sea, which is an increase of 25% compared to the average of 1958-1990. While the loads of dissolved silica (SiO2), dissolved inorganic carbon (DIC), Ca2+ and Mg2+ compared well with the long-term averages since the 1950s, loads of Na+, Cl-, SO4 2-, have tripled since 1958-1990. The increase of SO4 2- is attributed to the burning of coal in the catchment, and 18% of the F- load is estimated to originate from this source. The increase of Na+ and Cl- loads may be anthropogenic as well. The load of dissolved inorganic nitrogen (DIN) has increased 15 fold since the early measurements around 1970 and amounts to 1.6 Mt-N/yr today. The particulate concentrations of the typical anthropogenic trace metals Cd, Cr, Cu, Ni, Pb, and Zn showed enrichment factors between 0.7-7 compared to the natural background. Their annual peak concentrations all exceeded the quality targets recommended by the EC up to two times. However, the load of trace elements at Datong decreased by 73-86% (As: 50%) in the past ten years. Copyright 2012 by the American Geophysical Union.


Pan Y.,CAS Research Center for Eco Environmental Sciences | Shi Y.,CAS Research Center for Eco Environmental Sciences | Wang J.,CAS Research Center for Eco Environmental Sciences | Jin X.,Tianjin University of Technology | Cai Y.,CAS Research Center for Eco Environmental Sciences
Bulletin of Environmental Contamination and Toxicology | Year: 2011

Detectable PFCs could be found in all samples. Perfluorooctanoic acid (PFOA) was the major PFC in river water, while perfluorooctane sulfonate (PFOS) was dominant in sediment and were 17- to 153-fold higher than those in water. PFCs concentrations in soil were little higher than those in sediment. In fish muscles PFOS showed the highest concentrations. Generally, PFC concentrations in fish were in the following rank order: crucian carp > silver carp> common carp. We suggested that there may be constant and diffuse pollution sources in Tianjin. Point sources also appeared to make significant contribution in the present study. © 2011 Springer Science+Business Media, LLC.


Huang C.,National Chiao Tung University | Lin J.-L.,National Chiao Tung University | Lee W.-S.,National Chiao Tung University | Pan J.R.,National Chiao Tung University | Zhao B.,CAS Research Center for Eco Environmental Sciences
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2011

Coagulation is an effective pre-treatment process in membrane filtration for recycling spent filter backwash water (SFBW). To optimize the operation of the coagulation/filtration process for SFBW recycling, it is important to understand the critical role of coagulation mechanism on membrane filtration. In this study, SFBW samples were coagulated with polyaluminum chloride (PACl), followed by a dead-end microfiltration (MF), and the mean permeate flux and permeate quality were determined. The results showed that pre-coagulation improved the flux decline and the degree of the improvement was closely related to coagulation mechanisms. The permeate flux was enhanced most effectively by precipitation charge neutralization (PCN) coagulation, followed by charge neutralization and then sweep flocculation. Close examination of cake properties indicated that the reduced cake resistance (Rc) was subjected to the coagulated SFBW flocs in response to different coagulation mechanism. Smaller flocs, induced by PCN, were more compact and stronger, forming less compressible cake, which facilitated membrane filtration, while slower membrane filtration was observed when more compressible cake formed from larger flocs of looser and weaker structure. Coagulation mechanism also governed the size distribution of SFBW floc, which is strongly related to the subsequent cake compressibility as well as membrane permeability in membrane filtration. © 2011 Elsevier B.V.


Chen B.,Beijing Normal University | Wang R.,CAS Research Center for Eco Environmental Sciences
Ecological Indicators | Year: 2014

The editorial section of the special issue of Ecological Indicators focuses on describing integrated ecological indicators for sustainable urban ecosystem evaluation and management. It probes we aim to probe into the regulation measures to optimize the configuration of water resources and realize the integration of the fundamental research innovation and the management practice, thus providing decision support for the integration of water security, ecological security and sustainable socio-economic development of cities and regions. A group of researchers introduces a new multi-layered indicator set for urban metabolism studies, which is designed to gather information on the definition, biophysical characteristics, and metabolic flows of megacities.


Pei Z.,CAS Research Center for Eco Environmental Sciences | Shan X.-Q.,CAS Research Center for Eco Environmental Sciences | Kong J.,CAS Research Center for Eco Environmental Sciences | Kong J.,Fujian Normal University | And 2 more authors.
Environmental Science and Technology | Year: 2010

The coadsorption of ciprofloxacin (Cip) and Cu(II) on montmorillonite and kaolinite was studied between pH 4.0 and 9.5. At pH < 5.0, Cu2+, Cip+ and [Cu(II)(Cip±]2+ were the main species in solution. Between pH 5.0-7.0 [Cu(II)(Cip±] 2+ was the dominant complex species. Above pH 8.0 [Cu(II)(Cip -)2]0 precipitated. The presence of Cu(II) exerted no effect on the Cip sorption onto montmorillonite at low pH, whereas it increased Cip sorption on montmorillonite at pH > 6.0 due to the stronger affinity of Cip-Cu(II) complexes compared to sole Cip- or Cip ±, or Cip sorption via a Cu(II) bridge increased. In contrast, Cip increased Cu(II) adsorption on montmorillonite at pH < 7.0, whereas it decreased the adsorption of Cu(II) on kaolinite at pH 6.0-8.0. Cip was sorbed onto the kaolinite surface via interaction of carboxyl groups over the entire pH range. At pH 4.0-4.7, Cip+ sorption onto kaolinite's positively charged surface was more favorable than sorption of Cip-Cu(II) complexes. Batch experiments and FTIR analyses indicated that the coordination between Cip ±, Cip- and Cu(II) were most likely present on kaolinite surface at pH 7.0. At pH > 8.0, Cu(OH)2 (s) and [Cu(II)(Cip-)2]0 precipitated out of solution or on the montmorillonite or kaolinite surface, which was not considered evidence for either the sorption of Cip or the adsorption of Cu(II). © 2010 American Chemical Society.


Kang J.,CAS Research Center for Eco Environmental Sciences | Kang J.,Hubei Provincial Research Institute of Environmental Science | Liu H.,CAS Research Center for Eco Environmental Sciences | Zheng Y.-M.,National University of Singapore | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2011

Extensive usage of tetracycline has resulted in its contamination in surface water and groundwater. The adsorption of tetracycline on zeolite beta was systematically investigated for the decontamination of the antibiotic polluted water in this study. Ninety percent of uptake by the zeolite beta occured in 0.25. h, and the adsorption equilibrium was obtained within 3. h, which was well described by an intraparticle diffusion model. The adsorption generally increased when pH was increased from 4.0 to 5.0, and then decreased significantly as the pH was further increased, which was caused by the pH-dependent speciation of tetracycline and surface charge of zeolite beta. Both Freundlich and Langmuir equations well described the adsorption isotherm. A thermodynamic analysis showed that the sorption process was spontaneous and endothermic. Aluminum atoms in the zeolite played a crucial role in the uptake; the adsorption increased with the increasing aluminum content in zeolite. The UV-Visible spectroscopy study showed that the spectra of tetracycline changed upon the interaction with zeolite beta, which could be ascribed to the formation of complexes of tetracycline and aluminum atoms in the zeolite surface. Nuclear magnetic resonance spectroscopy study further confirmed the participation of Al in the tetracycline adsorption. Fourier transform infrared spectroscopy studies showed that the amino functional groups in tetracycline were involved in the complexation with the zeolite surface. © 2010 Elsevier Inc.


Yan M.,Peking University | Wang D.,CAS Research Center for Eco Environmental Sciences | Korshin G.V.,University of Washington | Benedetti M.F.,University Paris Diderot
Water Research | Year: 2013

This study introduces the concept of consistent examination of changes of log-transformed absorbance spectra of dissolved organic matter (DOM) at incrementally increasing concentrations of heavy metal cations such as copper, cadmium, and aluminum at environmentally relevant concentrations. The approach is designed to highlight contributions of low-intensity absorbance features that appear to be especially sensitive to DOM reactions. In accord with this approach, log-transformed absorbance spectra of fractions of DOM from the Suwannee River were acquired at varying pHs and concentrations of copper, cadmium, and aluminum. These log-transformed spectra were processed using the differential approach and used to examine the nature of the observed changes of DOM absorbance and correlate them with the extent of Me-DOM complexation. Two alternative parameters, namely the change of the spectral slope in the range of wavelengths 325-375 nm (DSlope325-375) and differential logarithm of DOM absorbance at 350 nm (DLnA350) were introduced to quantify Cu(II), Cd(II), and Al(III) binding onto DOMs. DLnA350 and DSlope325-375 datasets were compared with the amount of DOM-bound Cu(II), Cd(II), and Al(III) estimated based on NICA-Donnan model calculations. This examination showed that the DLnA350 and DSlope325-375 acquired at various pH values, metal ions concentrations, and DOM types were strongly and unambiguously correlated with the concentration of DOM-bound metal ions. The obtained experimental results and their interpretation indicate that the introduced DSlope325-375 and DLnA35 parameters are predictive of and can be used to quantify in situ metal ions interactions with DOMs. The presented approach can be used to gain more information about DOM-metal interactions and for further optimization of existing formal models of metal-DOM complexation. © 2013 Elsevier Ltd.


Zhan A.,CAS Research Center for Eco Environmental Sciences | Zhan A.,University of Windsor | Bailey S.A.,Canadian Department of Fisheries and Oceans | Heath D.D.,University of Windsor | Macisaac H.J.,University of Windsor
Molecular Ecology Resources | Year: 2014

Metabarcode surveys of DNA extracted from environmental samples are increasingly popular for biodiversity assessment in natural communities. Such surveys rely heavily on robust genetic markers. Therefore, analysis of PCR efficiency and subsequent biodiversity estimation for different types of genetic markers and their corresponding primers is important. Here, we test the PCR efficiency and biodiversity recovery potential of three commonly used genetic markers - nuclear small subunit ribosomal DNA (18S), mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (mt16S) - using 454 pyrosequencing of a zooplankton community collected from Hamilton Harbour, Ontario. We found that biodiversity detection power and PCR efficiency varied widely among these markers. All tested primers for COI failed to provide high-quality PCR products for pyrosequencing, but newly designed primers for 18S and 16S passed all tests. Furthermore, multiple analyses based on large-scale pyrosequencing (i.e. 1/2 PicoTiter plate for each marker) showed that primers for 18S recover more (38 orders) groups than 16S (10 orders) across all taxa, and four vs. two orders and nine vs. six families for Crustacea. Our results showed that 18S, using newly designed primers, is an efficient and powerful tool for profiling biodiversity in largely unexplored communities, especially when amplification difficulties exist for mitochondrial markers such as COI. Universal primers for higher resolution markers such as COI are still needed to address the possible low resolution of 18S for species-level identification. © 2014 John Wiley & Sons Ltd.


Yan M.,Peking University | Wang D.,CAS Research Center for Eco Environmental Sciences | Ma X.,CAS Research Center for Eco Environmental Sciences | Ni J.,Peking University | Zhang H.,Safe Drinking Water Center for Ruralarea
Separation and Purification Technology | Year: 2010

The removal of trihalomethanes (THMs) precursor and natural organic matter (NOM) by an integrated process of ozonation and biological granular activated carbon filtration (BGAC) as a deep water treatment process was investigated in pilot-scale tests. A comparison is also made with granular activated carbon filtration (GAC). The characteristics of the THMs precursor and the THMs formation potential (THMFP) were investigated by resin adsorption and ultrafiltration. The results show that the integrated process of ozonation and BGAC (O3/BGAC) is obviously superior to GAC for the removal of the THMs precursor because a considerable synergetic effect occurs between the ozonation and the BGAC. Although ozonation can limitedly remove dissolved organic carbon (DOC), it can cut down the molecular weight of the NOM, change its polarity, decrease the THMFP, and obviously enhance the efficiency of the BGAC. The BGAC could efficiently remove the hydrophobic base (HoB), hydrophobic neutral (HoN), weakly hydrophobic acid (WHoA), and low molecular weight fraction DOC that was produced in the optimized ozonation process. However, the BGAC stage should be carefully controlled to avoid the leakage of microbes and/or the products of metabolism because it has a high risk for producing THMs in following chlorination process. © 2010 Elsevier B.V. All rights reserved.


Lu N.,CAS Research Center for Eco Environmental Sciences | Fu B.,CAS Research Center for Eco Environmental Sciences | Jin T.,China Institute of Water Resources and Hydropower Research | Chang R.,CAS Chengdu Institute of Mountain Hazards and Environment
Landscape Ecology | Year: 2014

Trade-off is defined as a situation where one ecosystem service (ES) increases while another decreases. In a broader sense, trade-off also refers to unidirectional changes with uneven paces or rates in ESs. Although trade-off analysis for multiple ESs is more integral for ecosystem assessment and management, studies regarding trade-offs are rare in the literature, especially at the landscape scale or across large environmental gradients. Here, we evaluated the co-variations of multiple ESs of black locust (Robinia pseudoacacia) plantations along a precipitation gradient (400–650 mm) on the Loess Plateau using a quantitative trade-off approach. The multiple ESs had complex relationships, with significant regional variations along the gradient. Aboveground carbon, soil organic carbon (SOC), soil total nitrogen (STN), and soil water content (SWC) showed increasing trends with precipitation, but understory plant diversity (UPD) did not. The highest trade-offs were between UPD and SWC and the lowest trade-offs were between SOC and STN among all of the ES pairs. The differences in the trade-offs of varied ES combinations could be the result of unique competition relationships, mass allocation strategies, and time lags. Stand age appeared to be another critical variable in determining the values of ESs and their trade-offs along the precipitation gradient. The decreasing SWC with stand age indicated that the gaining of the other ESs was at the cost of SWC consumption. Because multiple ESs and their trade-offs exhibit high spatial variations across the landscape, spatially explicit management is needed to maintain the benefits while mitigating negative impacts in this water-limited landscape. © 2014, Springer Science+Business Media Dordrecht.


Zhang X.,Fujian Normal University | Lin Y.-m.,Fujian Normal University | Shan X.-q.,CAS Research Center for Eco Environmental Sciences | Chen Z.-l.,Fujian Normal University
Chemical Engineering Journal | Year: 2010

The degradation of 2,4,6-trinitrotoluene (TNT) in wastewater using nanoscale zero-valent iron (nZVI) was investigated. The results showed that >99% TNT was degraded when the initial TNT concentration was 80 mg L-1 after degradation for 3 h by 5 g L-1 of nZVI at pH 4, 40 °C using a rotary oscillation incubator operating at 200 rpm. The Langmuir-Hinshelwood kinetics model fit the kinetics of TNT degradation by nZVI well. Fourier transform infrared (FT-IR) and ultraviolet-visible spectrophotometry showed that TNT was adsorbed on the surface of nZVI, and this reduced TNT in aqueous solution. X-ray diffraction (XRD) demonstrated that the surface of nZVI changed during the degradation of TNT. © 2010 Elsevier B.V. All rights reserved.


Liu Z.,CAS Research Center for Eco Environmental Sciences | Han G.,National University of Singapore
Fuel | Year: 2015

Low temperature pyrolysis was employed to produce solid fuel biochars from woody (pine wood) and non-woody biomass (coconut fiber) in the present study. Chemical evolution of biomass under pyrolysis conditions was determined and fuel qualities of the biochars were evaluated including energy densities, ash-related problems and combustion behaviors. The results showed that dehydration reaction of the biomass had same preference with decarboxylation reaction under pyrolysis conditions. The hemicellulose and cellulose in non-woody biomass showed faster decomposition than those in woody biomass. The biochars derived from coconut fiber showed lower energy densities and energy yields than those from pine wood under identical conditions. All major ash forming metals originally contained in raw biomass were accumulated in the resultant biochars and more serious slagging and fouling problems were present during combustion of pyrolytic biochars compared to raw biomass. The reactivity of biomass decreased and the main mass loss shifted to elevated temperature zone with the increasing pyrolysis temperature, indicating increased thermal efficiency and environmental benefits were achievable during biochar combustion compared to raw biomass combustion. Taking into account combustion characteristics and energy yield, optimal pyrolysis temperatures for solid fuel production were around 300 °C for coconut fiber and 330 °C for pine wood. © 2015 Elsevier Ltd. All rights reserved.


Liu H.,CAS Research Center for Eco Environmental Sciences | Yang F.,CAS Research Center for Eco Environmental Sciences | Yang F.,University of Chinese Academy of Sciences | Zheng Y.,National University of Singapore | And 4 more authors.
Water Research | Year: 2011

Technology for immobilization of biomass has attracted a great interest due to the high sorption capacity of biomass for sequestration of toxic metals from industrial effluents. However, the currently practiced immobilization methods normally reduce the metal sorption capacities. In this study, an innovative ion-imprint technology was developed to overcome the drawback. Copper ion was first imprinted onto the functional groups of chitosan that formed a pellet-typed sorbent through the granulation with Sargassum sp.; the imprinted copper ion was chemically detached from the sorbent, leading to the formation of a novel copper ion-imprinted chitosan/. Sargassum sp. (CICS) composite adsorbent. The copper sorption on CICS was found to be highly pH-dependent and the maximum uptake capacity was achieved at pH 4.7-5.5. The adsorption isotherm study showed the maximum sorption capacity of CICS of 1.08 mmol/g, much higher than the non-imprinted chitosan/. Sargassum sp. sorbent (NICS) (0.49 mmol/g). The used sorbent was reusable after being regenerated through desorption. The FTIR and XPS studies revealed that the greater sorption of heavy metal was attributed to the large number of primary amine groups available on the surfaces of the ion-imprinted chitosan and the abundant carboxyl groups on Sargassum sp. Finally, an intraparticle surface diffusion controlled model well described the sorption history of the sorbents. © 2010 Elsevier Ltd.


Wang W.,CAS Research Center for Eco Environmental Sciences | Ren S.,CAS Research Center for Eco Environmental Sciences | Zhang H.,CAS Research Center for Eco Environmental Sciences | Yu J.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Water Research | Year: 2011

Due to their high carcinogenicity, the control of nitrosamines, a group of disinfection by-products (DBPs), is an important issue for drinking water supplies. In this study, a method using ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry was improved for simultaneously analyzing nine nitrosamines in source water and finished water samples of twelve drinking water treatment plants (DWTPs) in China. The method detection limits of the nine target analytes were 0.2-0.9 ng/L for the source water samples and 0.1-0.7 ng/L for the finished water samples. Of the nine nitrosamines, six (N-nitrosodimethylamine (NDMA), nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMor), N-nitrosodi-n-butylamine (NDBA), N-nitrosomethylethylamine (NMEA), and N-nitrosodiphenylamine (NDPhA)) were detected. The total nitrosamine concentrations in source water and finished water samples were no detection-42.4 ng/L and no detection-26.3 ng/L, respectively, and NDMA (no detection-13.9 ng/L and no detection-20.5 ng/L, respectively) and NDEA (no detection-16.3 ng/L and no detection-14.0 ng/L, respectively) were the most abundant. Meanwhile, the occurrence of nine secondary amines corresponding to the nine nitrosamines was also investigated. All of them except for di-n-propylamine were detected in some source water and finished water samples, and dimethylamine (no detection-3.9 μg/L and no detection-4.0 μg/L, respectively) and diethylamine (no detection-2.4 μg/L and no detection-1.8 μg/L, respectively) were the most abundant ones. Controlled experiments involving chloramination of four secondary amines confirmed that dimethylamine, diethylamine, morpholine and di-n-butylamine in water can form the corresponding nitrosamines, with diethylamine and morpholine showing significantly higher yields than dimethylamine which has already been identified as a precursor of NDMA. This study proved that diethylamine, morpholine and di-n-butylamine detected in raw water would be one of the important the precursors of NDEA, NMOR and NDBA, respectively, in drinking water. © 2011 Elsevier Ltd.


Wang W.,CAS Research Center for Eco Environmental Sciences | Hu J.,Peking University | Yu J.,CAS Research Center for Eco Environmental Sciences | Yang M.,CAS Research Center for Eco Environmental Sciences
Journal of Environmental Sciences | Year: 2010

The method for detecting N-nitrosodimethylamine (NDMA) in drinking water using ultra performance liquid chromatography (UPLC) coupled with tandem mass spectrometry (MS/MS) was improved by optimizing the clean-up procedure to remove the matrix interference in pretreatment process, and was then applied to a survey of NDMA in both raw and finished water samples from five water treatment plants in South China. The NDMA concentrations ranged from 4.7 to 15.1 ng/L in raw water samples, and from 4.68 to 46.9 ng/L in finished water. The NDMA concentration in raw water was found to be related with nitrite concentration, and during the treatment, the NDMA concentration increased following ozonation but decreased after subsequent activated carbon treatment. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.


Yan M.,Peking University | Yan M.,University of Washington | Korshin G.,University of Washington | Wang D.,CAS Research Center for Eco Environmental Sciences | Cai Z.,University of Washington
Chemosphere | Year: 2012

High-performance liquid chromatography-size exclusion chromatography (HPLC-SEC) coupled with a multiple wavelength absorbance detector (200-445nm) was used in this study to investigate the apparent molecular weight (AMW) distributions of dissolved organic matter (DOM). Standard DOM, namely humic acid, fulvic acid and hydrophilic acid, from the Suwannee River were tested to ascertain the performance and sensitivity of the method. In addition to four compounds groups: humic substances (Peak 1, AMW 16kD), fulvic acids (Peak 2, AMW 11kD), low AMW acids (Peak 3, AMW 5kD), and low AMW neutral and amphiphilic molecules, proteins and their amino acid building blocks (Peak 4, AMW 3kD), an new group that appears to include low AMW, 6-10kD, humic substances was found based on investigating the spectra at various elution times. The spectroscopic parameter S >365 (slope at wavelengths >365nm) was determined to be a good predictor of the AMW of the DOM. The detector wavelength played an important role in evaluating the AMW distribution. For some fractions, such as the humic and low AMW non-aromatic substances, the error in measurement was ±30% as determined by two-dimensional chromatograms detected at an artificially selected wavelength. HPLC-SEC with multiple wavelength absorbance detection was found to be a useful technique for DOM characterization. It characterized the AMW distributions of DOM more accurately and provided additional, potentially important information concerning the properties of DOM with varying AMWs. © 2012 Elsevier Ltd.


Wang X.-B.,Peking University | Wang X.-B.,CAS Research Center for Eco Environmental Sciences | Wang X.-B.,University of Chinese Academy of Sciences | Chi C.-Q.,Peking University | And 5 more authors.
Bioresource Technology | Year: 2011

A novel bacterial strain, DQ12-45-1b, was isolated from the production water of a deep subterranean oil-reservoir. Morphological, physiological and phylogenetic analyses indicated that the strain belonged to the genus Dietzia with both alkB (coding for alkane monooxygenase) and CYP153 (coding for P450 alkane hydroxylase of the cytochrome CYP153 family) genes and their induction detected. It was capable of utilizing a wide range of n-alkanes (C6-C40), aromatic compounds and crude oil as the sole carbon sources for growth. In addition, it preferentially degraded short-chain hydrocarbons (≤C25) in the early cultivation phase and accumulated hydrocarbons with chain-lengths from C23 to C27 during later cultivation stage with crude oil as the sole carbon source. This is the first study to report the different behaviors of a bacterial species toward crude oil degradation as well as a species of Dietzia degrading a wide range of hydrocarbons. © 2011 Elsevier Ltd.


Yang F.,CAS Research Center for Eco Environmental Sciences | Yang F.,University of Chinese Academy of Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences | Qu J.,CAS Research Center for Eco Environmental Sciences | Paul Chen J.,National University of Singapore
Bioresource Technology | Year: 2011

A new biosorbent - Sargassum sp. encapsulated with epichlorohydrin (ECH) cross-linked chitosan (CS) was investigated for nickel ions removal. The prepared biosorbent with Sargassum sp. to cross-linked chitosan of 3 (weight ratio) had the highest sorption capacity. The biosorption kinetics can be well fitted by the diffusion-controlled model. The organic leaching of CS was 77-88% less than that of algae at different pH. The biosorption capacity of nickel on CS was much higher than that of cross-linked chitosan (CLC) bead and lower than that of raw algae due to encapsulation. In addition, the reusability of CS was further evaluated and confirmed through five adsorption-desorption cycles. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the nickel ions sequestration mechanism included ion exchange and nickel complexation with the carboxyl, amino, alcoholic and ether groups in CS. © 2010 Elsevier Ltd.


Li J.,CAS Research Center for Eco Environmental Sciences | Wang J.,CAS Research Center for Eco Environmental Sciences | Luan Z.,CAS Research Center for Eco Environmental Sciences | Deng Y.,CAS Research Center for Eco Environmental Sciences | Chen L.,Peking University
Bioresource Technology | Year: 2011

A two-stage UASB reactor was employed to pretreat acrylic fiber manufacturing wastewater. Mesophilic operation (35 ± 0.5 °C) was performed with hydraulic retention time (HRT) varied between 28 and 40. h. Mixed liquor suspended solids (MLSS) in the reactor was maintained about 8000. mg/L. The results showed COD and sulfate removal could be kept at 51% and 75%, respectively, when the HRT was no less than 38. h. Sulfate reduction mainly occurred in the acidification-stage reactor while methane production mainly occurred in the methane-stage reactor. The size of granule formed in the acidification-stage reactor ranged between 1 and 5. mm while the largest size of granule in the methane-stage reactor ranged from 0.5 to 2. mm. Compared to microbial populations in the acidification-stage reactor, the microbial diversity in methane-stage reactor was more abundant. In the acidification-stage reactor, the Syntrophobacter sulfatireducens devoted to both sulfate reduction and acetate production. © 2011 Elsevier Ltd.


Zhan A.,CAS Research Center for Eco Environmental Sciences | MacIsaac H.J.,University of Windsor
Conservation Genetics | Year: 2015

Identification of rare species and mapping their distributions is crucial for understanding natural species distributions and causes and consequences of accelerating species declines. However, detection of rare species in both terrestrial and especially aquatic communities typically dominated by numerous microscopic species (i.e. rare biosphere) represents a formidable technical challenge. Rapid advances in high-throughput sequencing (HTS) technologies have revolutionized biodiversity studies in the rare biosphere, and also stimulated associated debates. Here we summarize research progress, discuss debates and problems, and propose possible solutions and future studies to address these issues. In addition, we provide take-home messages for experimental design and data interpretation when utilizing HTS techniques for rare biosphere exploration in ecology and conservation biology. © 2014, Springer Science+Business Media Dordrecht.


Jin X.,Tianjin University of Technology | Wang X.,Tianjin University of Technology | Yue J.,Tianjin University of Technology | Cai Y.,CAS Research Center for Eco Environmental Sciences | Zhang H.,Tianjin University of Technology
Electrochimica Acta | Year: 2010

Ordinary electrolysis developed spontaneously to contact glow discharge electrolysis (CGDE) at sufficiently high voltage, with glow discharge taking place around a thin platinum anode which was in contact with electrolyte solution. During this transition, the critical voltage (VD) was an important parameter for the onset of CGDE. The results indicated that V D decreased with the increasing conductivity and then maintained a certain value. The different dimension and material of cathode had little effect on VD. When the electrolyte conductivity was 5.0 mS/cm, V D was hardly affected by electrolyte composition. And the concentrations of H2O2 producing in the anolyte were close in different inert electrolyte. However, the concentrations of H 2O2 in NaCl, NaAc, Na2CO3 and NaHCO3 solution were lower than that in Na2SO4 solution. And the concentration of H2O2 in the anolyte was also decreased by adding a minute amount of CH3OH. © 2010 Elsevier Ltd. All rights reserved.


Chen W.,CAS Research Center for Eco Environmental Sciences | Xu J.,Chinese Research Academy of Environmental Sciences | Lu S.,CAS Research Center for Eco Environmental Sciences | Jiao W.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemosphere | Year: 2013

Fates and transport of 9 commonly found PPCPs of the reclaimed water were simulated based on the HYDRUS-1D software that was validated with data generated from field experiments. Under the default scenario in which the model parameters and input data represented the typical conditions of turf grass irrigation in southern California, the adsorption, degradation, and volatilization of clofibric acid, ibuprofen, 4-tert-octylphenol, 4-n-nonylphenol, naproxen, triclosan, diclofenac sodium, bisphenol A and estrone in the receiving soils were tracked for 10years. At the end, their accumulations in the 90cm soil profile varied from less than 1ngg-1 to about 140ngg-1 and their concentrations in the drainage water in the 90cm soil depth varied from nil to μgL-1 levels. The adsorption and microbial degradation processes interacted to contain the PPCPs entirely within surface 40cm of the soil profiles. Leaching and volatilization were not significant processes governing the PPCPs in the soils. The extent of accumulations in the soils did not appear to produce undue ecological risks to the soil biota. PPCPs did not represent any potential environmental harm in reclaimed water irrigation. © 2013 Elsevier Ltd.


Li X.,CAS Research Center for Eco Environmental Sciences | Li X.,Smithsonian Environmental Research Center | Weller D.E.,Smithsonian Environmental Research Center | Jordan T.E.,Smithsonian Environmental Research Center
Journal of Hydrology | Year: 2010

Recent advances in optimizing watershed model calibration have focused mainly on incorporating multiple objective measures of model performance and improving optimization algorithms. However, some parameters vary widely among different calibration locations. We present a watershed model calibration method that combines multi-objective optimization with averaging across multiple calibration sites. Model parameters were first estimated by multi-objective optimization at each calibration site, and then finalized by weighted averaging the parameter values across sites. The weight for each site was calculated from the prediction error at that site. The calibration framework was applied to estimate 16 hydrological and nutrient parameters of the General Watershed Loading Function (GWLF) watershed model at the Rhode River basin, in Maryland, United States of America. When calibrated to a single watershed, GWLF gave reasonable predictions for monthly streamflow (r2 = 0.71-0.78), monthly total nitrogen (TN) loads (r2 = 0.55-0.65), annual streamflow (r2 = 0.80-0.91), and annual TN loads (r2 = 0.67-0.86); but success for total phosphorus (TP) loads varied among watersheds (r2 = 0.41-0.68 for monthly TP loads and r2 = 0.47-0.79 for annual TP loads). In comparison to the single-site calibrations, the multi-site weighted average approach combined with multi-objective optimization reduced the relative cumulative error of predictions in validation watersheds by 3.5-7.4% for monthly streamflow, 3.2-6.3% for monthly TN loads, and 4.3-5.9% for monthly TP loads, respectively. © 2009 Elsevier B.V. All rights reserved.


Yan M.,Peking University | Li M.,Peking University | Wang D.,CAS Research Center for Eco Environmental Sciences | Xiao F.,CAS Research Center for Eco Environmental Sciences
Chemosphere | Year: 2013

In this work, absorbance and fluorescence spectra were used to study iron binding to standard Suwannee River fulvic acid (SRFA). The differential logarithm-transformed absorbance and fluorescence spectra of SRFA induced by iron binding were processed to examine the nature of the observed phenomena and to investigate the contributions of discrete binding sites present in SRFA. Both the Fe-differential log-transformed absorbance and fluorescence were well correlated to the bound iron concentrations predicted based on the Non-ideal Competitive Adsorption (NICA-Donnan) model at iron concentrations below 10.0μM (R2>0.99 for absorbance and R2>0.97 for fluorescence) and over a wide pH range of 3.5-8.0. At pH3.5, both the Fe-differential log-transformed absorbance and fluorescence vs. iron bound spectra exhibited significantly lower slopes than those at pH5.0, 7.0, and 8.0. These results suggest that a different set of complexation-active chromophores and fluorophores are responsible for iron binding at low pH values or that the NICA-Donnan model is limited at low pH. Because phenolic and carboxylic complex sites of different fluorophores respond to iron quenching, the fluorescence data indicate three stages of iron binding to phenolic, carboxylic, and Donnan gels (electrostatic interactions) in SRFA (with R2>0.99 at each stage). The agreement between observations from spectroscopic indices and established metal-binding models shows that the absorbance and fluorescence spectra provide important information about the involvement of metal complexation of specific functional groups typical for fulvic acids. © 2013 Elsevier Ltd.


Shi X.,CAS Institute of Tibetan Plateau Research | Wu L.,Zhejiang University | Wu L.,University of California at Riverside | Chen W.,CAS Research Center for Eco Environmental Sciences | Wang Q.,CAS Institute of Soil and Water Conservation
Soil Science Society of America Journal | Year: 2011

Transfer of agrochemicals from the soil surface to overland flow is a key process governing pollutant transport from soil to surface waters. Simulation models are effective tools for predicting pollutant loads from overland flow to surface water. In this study, we reviewed and summarized experimental observations to assess the factors that affect this transfer process, including: rainfall, topography, soil hydraulic properties, initial water and solute conditions, and management practices. Th eoretical frameworks and models for describing the transfer process were also reviewed. The existing models were classified into four categories based on their principles: mixing-layer models, interfacial diff usion-controlled models, interfacial-diffusion and rainfall-dispersion models, and empirical models. The assumptions, parameters, applications, limitations or potential issues, and further improvements for each category of the models were discussed. It is recommended that new experimental methods be developed and current theoretical frameworks be further refined by considering the effects of other environmental factors and transport mechanisms on solute transfer from the soil surface to overland flow so that the models can be applied to a wider range of practical field conditions. © Soil Science Society of America.


He C.,Beijing Normal University | Tian J.,Georgia Southern University | Shi P.,Beijing Normal University | Hu D.,CAS Research Center for Eco Environmental Sciences
Landscape and Urban Planning | Year: 2011

Based on the existing Urban Expansion Dynamic (UED) model, this paper develops a geographic information system (GIS)-based model that can be used to assess the current and potential spatial stress on a regional wetland ecosystem due to urban expansion. Synthetically utilizing the simulation capability of the UED model and the spatial analysis power of a GIS, this new model takes into account the present disturbance by ongoing urban expansion, the potential disturbance by future urban expansion, the accessibility via the transportation network, and the neighborhood stability. The model is used in particular to simulate the spatial stress on the major wetlands in Beijing from 1991 to 2004. The simulation results are found to be consistent with the actual remote sensing observations: a relatively high spatial stress normally leads to an eventual conversion into urban use. With the future urban lands predicted by the UED model, this model is used to further assess the potential spatial stress of urban expansion on the major wetlands in Beijing by 2015. Moreover, the spatially stressed wetland fringe areas in Beijing are identified based on the total spatial stress combining the current and the potential. These areas are found to be mainly distributed in downtown Beijing and the plains areas that have relatively easy accessibility via the transportation network. Effective measures should be taken to protect such areas from being further disturbed in order to achieve the goal of a more effective conservation of the wetland ecosystems in Beijing. © 2011 Elsevier B.V.


Zhou W.,CAS Research Center for Eco Environmental Sciences | Cadenasso M.L.,University of California at Davis
Landscape Ecology | Year: 2012

Landscape ecology links landscape pattern to ecological function. Achieving this goal hinges on accurate depiction and quantification of pattern, which is frequently done by visually interpreting remotely sensed imagery. Therefore, understanding both the accuracy of that interpretation and what influences its accuracy is crucial. In addition, imagery is pixel-based but landscape pattern exists, more realistically, as irregularly shaped patches. Patches may contain only one feature type such as trees, but, in some landscapes, patches may contain several different types of features such as trees and buildings. Using a patch-based approach, this paper investigates two types of variables-whole-patch and within-patch-that are hypothesized to influence the accuracy of visually estimating the cover of features within patches. A highly accurate reference map, obtained from object-based classification, was used to evaluate the accuracy of visual estimates of cover within patches. The effects of the variables on the accuracy of these estimates were tested using logistic regressions and multimodel inferential procedures. Though all variables significantly affected the accuracy, the within-patch configuration of features is the most significant factor. In general, errors of cover estimates are more likely to occur when patches are smaller or have more complex shapes, and features within a patch are (1) more diverse; (2) more fragmented; (3) more complex in shape; and (4) physically less connected. These results provide an important first step towards a quantitative, spatially explicit model for predicting error of cover estimates and determining under what circumstances estimation error is most likely to occur. © 2012 Springer Science+Business Media B.V.


Wang C.,Beijing Normal University | Wang Z.,Beijing Normal University | Lin L.,Beijing Normal University | Tian B.,CAS Research Center for Eco Environmental Sciences | Pei Y.,Beijing Normal University
Journal of Hazardous Materials | Year: 2012

Effects of low molecular weight organic acids (LMWOAs; citric acid, oxalic acid and tartaric acid) on phosphorus (P) adsorption by ferric-alum water treatment residuals (FARs) were studied. Both batch and column experiments indicated that the effects of LMWOAs on P adsorption were closely related to adsorption time. Initially, all acids presented inhibitory function on P adsorption. The inhibition became weaker with time, eventually promoting P adsorption for citric acid and tartaric acid. In the column experiment with a 61-day duration, high P adsorption rates (>55%) were observed for the test groups containing citric acid and tartaric acid. Interestingly, higher pH likely enhanced P adsorption with the effects of LMWOAs and a distinct relationship between LMWOAs' effects on P adsorption and their concentrations was not observed. Moreover, fractionation of the adsorbed P from the FARs demonstrated that oxalic acid reduced P adsorption capacity, while citric acid and tartaric acid increased. Based on the forms of Fe and Al existing in the FARs and Fourier transform infrared spectroscopy analyses, LMWOAs can promote P adsorption through activating crystalline Fe/Al and preventing crystallization of amorphous Fe/Al to increase P adsorption sites, and can also inhibit P adsorption by competition with adsorption sites. © 2011 Elsevier B.V.


Pei Z.,CAS Research Center for Eco Environmental Sciences | Kong J.,Fujian Normal University | Shan X.-Q.,CAS Research Center for Eco Environmental Sciences | Wen B.,CAS Research Center for Eco Environmental Sciences
Journal of Hazardous Materials | Year: 2012

Effect of norfloxacin (Nor) on the sorption of 1,3-dinitrobenzene (1,3-DNB), and PAHs (naphthalene (NAPH), phenanthrene (PHEN) and pyrene (PYR)) to K +-montmorillonite was studied. Nor suppressed 1,3-DNB sorption due to their competition for the same sorption sites. 1,3-DNB was sorbed on K +-montmorillonite surface via cation-polar interaction and n-π electron donor-acceptor interaction. Nor also was sorbed on these sites through cation exchange, cation bridging and/or surface complexation. Nor increased three PAHs sorption on montmorillonite and the enhanced magnitude was positively correlated with the π-donor strength of three PAHs. The enhanced sorption of PAHs by Nor was primarily attributed to π-π interaction between π-electron-depleted quinoline ring of Nor and π-electron-rich PAHs. Compared with cation (Nor +) and anion (Nor -), zwitterion (Nor ±) of Nor increased PHEN and PYR sorption more pronounced due to additional cation-π interaction between the sorbed Nor ± and PAHs. 1H NMR spectrum provided direct evidence for π-π and cation-π complexation between PAHs and Nor + in solution by ring-current-induced upfield chemical shifts of amino group and methylene group of Nor +. © 2011 Elsevier B.V.


Gao Y.,CAS Chengdu Institute of Mountain Hazards and Environment | Gao Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Zhu B.,CAS Chengdu Institute of Mountain Hazards and Environment | Wang T.,CAS Chengdu Institute of Mountain Hazards and Environment | Wang Y.,CAS Research Center for Eco Environmental Sciences
Journal of Hydrology | Year: 2012

Bioavailable phosphorus (P) losses due to agriculture activity in a purple soil watershed in the Sichuan Basin of Southwestern China were monitored to define the hydrological controls of P transport. Our results indicate that the proportion of P that was transported in particulate form increased in the rainy season, and that the mass of total bioavailable P (BAP) loads exhibited seasonal fluctuations, wherein the majority (over 90%) was observed to have been exported between June and September. The proportion of bioavailable dissolved P (BDP) in the BAP discharge budget in the watershed varied between 11% and 15% during the monitoring period. The bioavailable particulate P (BPP) and BDP concentrations of stream water under rainstorm events increased by over 40% in comparison to their annual mean concentrations, and the annual BAP load was primarily dominated by the loads that occurred during rainstorm events in the study year. BAP concentration in groundwater significantly fluctuated with the seasons, and the ratio of total BAP in groundwater to that in surface water gradually increased during the rainy season. Thus, the impact of agriculture on the water quality of this watershed becomes clearly evident. © 2011 Elsevier B.V.


Yan M.,Peking University | Liu C.,Chang'an University | Wang D.,CAS Research Center for Eco Environmental Sciences | Ni J.,Peking University | Cheng J.,Chang'an University
Langmuir | Year: 2011

In this paper, a quartz crystal microbalance with dissipation monitoring (QCM-D) is used to investigate humic acid (HA) adsorption onto alumina (Al 2O 3). The amount of adsorption and layer structures of HA were determined by the real-time monitoring of resonance frequency and energy dissipation changes (Δf and ΔD). The effect of HA concentration, HA molecular characteristics (molecular weight and polarity), and pH on HA adsorption onto Al 2O 3 were investigated. The mass of HA adsorption increases as the concentration of HA increases. The masses are about 24, 60, and 87 ng cm -2 as the concentration of DOC is 1.0, 4.85, and 92.0 mg L -1, respectively. The adsorbed layer of HA is more nonrigid, and the mass of HA adsorption is higher at weakly acidic pH values. It was 20, 80, 65, and 45 ng cm -2 at pH values of 4.5, 5.5, 6.5, and 8.0, respectively. This reveals that efficient HA removal by coagulation at weakly acidic pH values is not just due to the hydrolysis of Al ions as previously presumed. The adsorbed layer of hydrophobic HA is more nonrigid than hydrophobic HA (fractionated by Amberlite XAD-8 resin), and the mass adsorption for the hydrophobic fraction is about four times higher than the hydrophilic fraction (120 ng cm -2 and 30 ng cm -2). The method is of value in the research to establish a quantified calculation model for the coagulation process. © 2011 American Chemical Society.


Ding H.,Peking University | Ding H.,CAS Research Center for Eco Environmental Sciences | Peng H.,Peking University | Yang M.,CAS Research Center for Eco Environmental Sciences | Hu J.,Peking University
Journal of Chromatography A | Year: 2012

A sensitive liquid chromatography-electrospray tandem mass spectrometry method was established for the simultaneous determination of five monosubstituted polyfluoroalkyl phosphates (monoPAPs) and eight disubstituted polyfluoroalkyl phosphates (diPAPs) in drinking water. Complete separation and good retention for 13 polyfluoroalkyls phosphates (PAPs) were achieved with a Waters ACUITY UPLC BEH C8 column using a mixture of methanol/water containing 0.1% NH 4OH as the mobile phases. Extraction of drinking water samples was performed on weak anion exchange (WAX) cartridges, and the recoveries of target compounds were from 65 to 110%. The limits of quantization (LOQs) for 13 analytes were in the range of 0.4-40ng/L. This method was applied to analyze the PAPs in drinking water samples from three cities in China. Of the 13 PAPs, six PAPs including 6:2 monoPAP (13.0ng/L), 8:2 monoPAP (3.6ng/L), 10:1 monoPAP (4.3-70.3ng/L), 10:2 monoPAP (1.4-5.6ng/L), 8:2 diPAP (0.10ng/L), and 10:1 diPAP (0.8-3.8ng/L) were detected. © 2012 Elsevier B.V.


Tian F.,CAS Research Center for Eco Environmental Sciences | Tian F.,Beijing Normal University | Qiu G.,University of Science and Technology of China | Yang Y.,CAS Institute of Genetics and Developmental Biology | And 2 more authors.
Journal of Hydrology | Year: 2013

Evapotranspiration (ET) is an energy balance component and a key component of water budget; thus, accurate estimates of ET are critical for understanding hydrological processes and water resources management. Despite growing concerns, challenges remain in estimating ET by remote sensing technology for regional applications, due to the difficulty in determination of aerodynamic, canopy and soil resistance. Instead of using resistance, ET and their partition of evaporation (Es) and transpiration (Ec) can be evaluated based on an extended three temperature model (3T model) and Moderate Resolution Imaging Spectroradiometer (MODIS) products for the period of 2001-2009. A case study was conducted in the Heihe River Basin in northwestern China. Validation results indicated that the mean absolute error was 0.08. mm/d, with a maximum and minimum absolute error of 1.28. mm/d and 0.02. mm/d, respectively, which presented a simple extended 3T model in estimating ET with adequate accuracy and could satisfy regional research requirement at large scales. Results showed that: (1) seasonally, ET was highest (varied from 0.80. mm/d to 1.27. mm/d with a mean value of 1.05. mm/d) in summer and lowest in winter (varied from 0.35. mm/d to 0.44. mm/d with a mean value of 0.37. mm/d); (2) spatially, it rendered a decrease from the Qilian Mountain of the upper reaches (515. mm/a) to the Gobi desert of the lower reaches (82. mm/a), which was closely related to land covers and climate conditions; (3) the comparison of different ecosystems indicated that forest has the highest ET (588. mm), followed by grassland (308. mm), farmland (225. mm), and desert land (160. mm); (4) ET was separated into Es and Ec, and about 38-72% soil water returned to the atmosphere in the form of Es. This information will prove to be useful for water-use efficiency of the Ecological Water Conveyances Project (EWCP) conducted in the basin. © 2013 Elsevier B.V.


Chen W.,CAS Research Center for Eco Environmental Sciences | Lu S.,CAS Research Center for Eco Environmental Sciences | Jiao W.,CAS Research Center for Eco Environmental Sciences | Wang M.,CAS Research Center for Eco Environmental Sciences | Chang A.C.,University of California at Riverside
Environmental Development | Year: 2013

Municipal wastewater reclamation and reuse provides an effective way to solve water resource problems in arid and semi-arid regions. Irrigation is the major reuse for reclaimed water. In this paper, we analyzed the benefits and risks associated with reclaimed water irrigation to demonstrate that it is a safe water resource when appropriately applied. The analysis showed that reclaimed water is an economical water resource with potential benefits in ameliorating soil health conditions and saving fertilizer. Salts, nitrogen and pathogens were the major risk sources for reclaimed water irrigation, while risks associated with heavy metals and emerging contaminants were low. Risk management practices were summarized. Given that there are huge potential benefits and the risks can be controlled by proper field management, irrigation with reclaimed water should be encouraged and promoted. © 2013 Elsevier B.V.


Jiao W.,CAS Research Center for Eco Environmental Sciences | Chen W.,CAS Research Center for Eco Environmental Sciences | Chang A.C.,University of California at Riverside | Page A.L.,University of California at Riverside
Environmental Pollution | Year: 2012

Application of phosphate fertilizer can be a significant contributor of potentially hazardous trace elements such as arsenic, cadmium, and lead in croplands. These trace elements have the potential to accumulate in soils and be transferred through the food chain. We articulated the environmental risks of trace elements associated with long-term phosphate fertilizer applications by combining data from the literature and results from model simulations. Results illustrate that under normal cropping practice, the impact of phosphate fertilizers applications on trace element accumulation in receiving soils has been limited and localized. Their plant uptake varied greatly depending on the fertilizer application rates, soil and plant characteristics. This has led to a great deal of uncertainty in characterizing soil distribution coefficients, K d, and plant uptake factors, PUF, two of the most used parameters in assessing the risks of accumulations. Therefore, the risks may be more appropriately assessed based on the probabilistic distributions of K d and PUF. © 2012 Elsevier Ltd. All rights reserved.


Wang X.,CAS Research Center for Eco Environmental Sciences | Yin R.,CAS Research Center for Eco Environmental Sciences | Shen H.,Chinese Institute of Urban Environment | Wang H.,CAS Research Center for Eco Environmental Sciences
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2011

Aberrant DNA methylation in human sperms has been proposed to be a possible mechanism associated with male infertility. We developed an ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method for rapid, sensitive, and specific detection of global DNA methylation level in human sperms. Multiple-reaction monitoring (MRM) mode was used in MS/MS detection for accurate quantification of DNA methylation. The intra-day and inter-day precision values of this method were within 1.50-5.70%. By using 2-deoxyguanosine as an internal standard, UPLC-MS/MS method was applied for the detection of global DNA methylation levels in three cultured cell lines. DNA methyltransferases inhibitor 5-aza-2′-deoxycytidine can significantly reduce global DNA methylation levels in treated cell lines, showing the reliability of our method. We further examined global DNA methylation levels in human sperms, and found that global methylation values varied from 3.79% to 4.65%. The average global DNA methylation level of sperm samples washed only by PBS (4.03%) was relatively lower than that of sperm samples in which abnormal and dead sperm cells were removed by density gradient centrifugation (4.25%), indicating the possible aberrant DNA methylation level in abnormal sperm cells. Clinical application of UPLC-MS/MS method in global DNA methylation detection of human sperms will be useful in human sperm quality evaluation and the study of epigenetic mechanisms responsible for male infertility. © 2011 Elsevier B.V.


Chen W.,CAS Research Center for Eco Environmental Sciences | Chen W.,University of California at Riverside | Hou Z.,Shihezi University | Wu L.,University of California at Riverside | And 2 more authors.
Plant and Soil | Year: 2010

The influences of different N fertilization rates and soil salinity levels on the growth and nitrogen uptake of cotton was evaluated with a pot experiment under greenhouse conditions. Results showed that cotton growth measured as plant height was significantly affected by the soil salinity and N-salinity interaction, but not by N alone. Cotton was more sensitive to salinity during the emergence and early growth stages than the later developmental stages. At low to moderate soil salinity, the growth inhibition could be alleviated by fertilizer application. Soil salinity was a dominated factor affecting cotton's above-ground dry mass and root development. Dry mass of seed was reduced by 22%, 52%, and 84% respectively, when the soil salinity level increased from control level of 2.4 dS m -1 to 7.7 dS m -1, 12.5 dS m -1 and to 17.1 dS m -1, respectively. N uptake increased with N fertilization at adequate rates at both low and medium soil salinities but was not influenced by over N fertilization. At higher salinities, N uptake was independent of N rates and mainly influenced by soil salinity. The uptake of K decreased with soil salinity. The concentration of Na, Cl and Ca in plant tissues increased with soil salinity with highest concentrations in the cotton leaf. © The Author(s) 2009.


Zheng M.-Z.,Chinese Institute of Urban Environment | Zheng M.-Z.,Wuyi University | Li G.,Chinese Institute of Urban Environment | Sun G.-X.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Plant and Soil | Year: 2013

Background and aims: Efficient accumulation of arsenic (As) in rice (Oryza sativa L.) poses a potential health risk to rice consumers. The aim of this study was to investigate the mechanisms of uptake, transport and distribution of inorganic arsenic (Asi) and dimethylarsinic acid (DMA) in rice plants. Methods: Rice was exposed to Asi (As(V)) and DMA in hydroponics. High-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and synchrotron X-ray fluorescence (SXRF) microprobe were used to determine As concentration and the in situ As distribution. Results: DMA induced abnormal florets before flowering and caused a sharp decline in the seed setting rate after flowering compared to Asi. Rice grains accumulated 2-fold higher DMA than Asi. The distribution of Asi concentration (root > leaf > husk > caryopsis) in As(V) treatments was different from that of the DMA concentration (caryopsis > husk > root ≥ leaf) in DMA treatments. SXRF showed that Asi mainly accumulated in the vascular trace of caryopsis with limited distribution to the endosperm, whereas DMA was observed in both tissues. Conclusions: DMA tended to accumulate in caryopsis and induced higher toxicity to the reproductive tissues resulting in markedly reduced grain yield, whereas Asi mainly remained in the vegetative tissues and had no significant effect on yield. DMA is more toxic than Asi to the reproductive tissues when both of them are at similar concentrations in nutrient solution. © 2012 Springer Science+Business Media B.V.


Kang J.,CAS Research Center for Eco Environmental Sciences | Kang J.,University of Chinese Academy of Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences | Zheng Y.-M.,National University of Singapore | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2010

Sorption of tetracycline and copper onto chitosan is systematically investigated in this study. The sorption of tetracycline and copper occurs rapidly in the first few hours and 90% of completed uptake occurs in the first 11-12 and 6 h, respectively. The sorption equilibrium of both contaminants is established in 24 h. The solution pH largely affects the sorption of both contaminants. The tetracycline uptake increases as pH is increased from 2.8 to 5.6, and 2.5 to 7 in the absence and the presence of copper, respectively. The presence of copper significantly improves the tetracycline adsorption likely due to the formation of cationic bridging of copper between tetracycline and chitosan. The maximum adsorption capacity and the adsorption affinity constant for tetracycline dramatically increase from 53.82 to 93.04 mmol kg-1 and from 1.22 to 10.20 L mmol-1 as the copper concentration is increased from 0 to 0.5 mmol L-1. The uptake of copper increases with an increase in pH from around 3.5-6.0 in the absence and the presence of tetracycline. The presence of tetracycline decreases the copper adsorption, which may be ascribed to the competition of tetracycline with copper ions for the adsorption sites at the chitosan surface. The adsorption isothermal data of both tetracycline and copper are fit well by the Langmuir equation. The maximum adsorption capacity and adsorption affinity constant of copper ions decrease from 1856.06 to 1486.20 mmol kg-1 and from 1.80 to 1.68 L mmol-1 in the absence and the presence of tetracycline. FTIR and XPS studies reveal that amino, hydroxyl, and ether groups in the chitosan are involved in the adsorption of tetracycline and copper. © 2009 Elsevier Inc. All rights reserved.


Li N.,CAS Research Center for Eco Environmental Sciences | Jiang W.,Shanghai Municipal Water Resource Development and Utilization National Engineering Center Co. | Ma M.,CAS Research Center for Eco Environmental Sciences | Wang D.,CAS Research Center for Eco Environmental Sciences | Wang Z.,CAS Research Center for Eco Environmental Sciences
Journal of Hazardous Materials | Year: 2016

There is increasing evidence of activities of chlorinated by-products of bisphenol A (BPA) on retinoic acid system. Their agonistic and antagonistic activities to human retinoid X receptor (RXR) were assessed by a two-hybrid yeast assay. Aqueous solutions of 1 mg/L BPA were chlorinated by sodium hypochlorite (NaClO). It showed that chlorination of BPA increased RXRβ antagonistic activity, while no agonistic activity was detected, showing chlorine might act as a toxic potentiator rather than a toxic deactivator in RXRβ disrupting effects. BPA and its byproducts including 2,2′,6,6′-tetrachlorobisphenol A (TCBPA) and 2,4,6-trichlorophenol (TCP) were quantitatively determined by gas chromatography/mass spectrometry (GC/MS). BPA rapidly degraded. With the increasing of ICC and reaction time, concentration of formed TCBPA increased initially then decreased, while concentration of formed TCP increased stably. Using the toxic equivalent (TEQ) approach, the main contributors should be mono-, di- and tri- chlorobisphenol A at initial chlorine concentration (ICC) of 1 mg/L. At ICC of 2 and 5 mg/L, the main contributors were TCBPA and TCP, being 57.7%–70.7% and 45.3%–59.4%. Molecular docking showed BPA chlorination by-products might have the same mode of action with BPA, forming hydrogen bond and pi–pi interaction with their OH group or hydrophobic ring. © 2016 Elsevier B.V.


Li T.,National University of Singapore | Li T.,CAS Research Center for Eco Environmental Sciences | He J.,National University of Singapore
Bioresource Technology | Year: 2016

Production of lignocellulosic butanol has drawn increasing attention. However, currently few microorganisms can produce biofuels, particularly butanol, from lignocellulosic biomass via simultaneous saccharification and fermentation. Here we report discovery of a wild-type, mesophilic Clostridium sp. strain MF28 that ferments xylan to produce butanol (up to 3.2 g/L) without the addition of saccharolytic enzymes and without any chemical pretreatments. Application of selective pressure from 2-deoxy-D-glucose facilitated isolation of strain MF28, which exhibits inactivation of genes (gid and ccp genes) responsible for carbon catabolite repression, thus allowing strain MF28 to simultaneously ferment a combination of glucose (30 g/L), xylose (15 g/L), and arabinose (15 g/L) to produce 11.9 g/L of butanol. Strain MF28 possesses several unique features: (i) non-sporulating, (ii) no acetone/ethanol, (iii) complete hemicellulose-binding enzymatic domain, and (iv) absence of carbon catabolite repression. These unique characteristics demonstrate the industrial potential of strain MF28 for cost-effective biofuel generation from lignocellulosic biomass. © 2016 Elsevier Ltd


Duan G.,CAS Research Center for Eco Environmental Sciences | Liu W.,Agricultural University of Hebei | Chen X.,Shanghai University | Hu Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Metallomics | Year: 2013

Rice is the main cereal crop that feeds half of the world's population, and two thirds of the Chinese population. Arsenic (As) contamination in paddy soil and irrigation water elevates As concentration in rice grains, thus rice consumption is an important As intake route for populations in south and south-east Asia, where rice is the staple food. In addition to direct toxicity of As to human, As may limit the accumulation of micro-nutrients in rice grains, such as selenium (Se) and zinc (Zn). These micro-nutrients are essential for humans, while mineral deficiencies, especially iron (Fe) and Zn, are prevalent in China. Therefore, it is important to understand the interactions between As and micro-nutrients in rice plants, which is the principal source of these nutrients for people on rice diets. In addition, during the processes of As uptake, translocation and transformation, the status of macro-nutrients (e.g. silicon (Si), phosphors (P), sulfur (S)) are important factors affecting As dynamics in soil-plant systems and As accumulation in rice grains. Recently, synchrotron-based spectroscopic techniques have been applied to map the distribution of As and nutrient elements in rice plants, which will aid to understand how As are accumulated, complexed and transported within plants. This paper reviews the interactions between As and macro-nutrients, as well as micro-nutrients in rice plants. © 2013 The Royal Society of Chemistry.


He C.,Beijing Normal University | Han L.,CAS Research Center for Eco Environmental Sciences | Zhang R.Q.,Murray State University
Environmental Pollution | Year: 2016

China's urbanization and the subsequent public vulnerability to degenerated environment is important to global public health. Among the environmental problems, fine particulate (PM2.5) pollution has become a serious hazard in rapidly urbanizing China. However, quantitative information remains inadequate. We thus collected PM2.5 concentrations and population census records, to illustrate the spatial patterns and changes in the PM2.5 hazard levels in China, and to quantify public vulnerability to the hazard during 2000–2010, following the air quality standards of World Health Organization. We found that 28% (2.72 million km2) of China's territory, including 78% of cities (154 cities) with a population of >1 million, was exposed to PM2.5 hazard in 2010; a 15% increase (1.47 million km2) from 2000 to 2010. The hazards potentially impacted the health of 72% of the total population (942 million) in 2010, including 70% of the young (206 million) and 76% of the old (71 million). This was a significant increase from the 42% of total the population (279 million) exposed in 2000. Of the total urban residents, 76% (501 million) were affected in 2010. Along with PM2.5 concentration increase, massive number of rural to urban migration also contributed greatly to China's urban public health vulnerability. © 2016 Elsevier Ltd


Chao J.-B.,CAS Research Center for Eco Environmental Sciences | Chao J.-B.,China Institute of Metrology | Liu J.-F.,CAS Research Center for Eco Environmental Sciences | Yu S.-J.,CAS Research Center for Eco Environmental Sciences | And 4 more authors.
Analytical Chemistry | Year: 2011

The rapid growth in commercial use of silver nanoparticles (AgNPs) will inevitably increase silver exposure in the environment and the general population. As the fate and toxic effects of AgNPs is related to the Ag + released from AgNPs and the transformation of Ag + into AgNPs, it is of great importance to develop methods for speciation analysis of AgNPs and Ag +. This study reports the use of Triton X-114-based cloud point extraction as an efficient separation approach for the speciation analysis of AgNPs and Ag + in antibacterial products and environmental waters. AgNPs were quantified by determining the Ag content in the Triton X-114-rich phase with inductively coupled plasma mass spectrometry (ICPMS) after microwave digestion. The concentration of total Ag +, which consists of the AgNP adsorbed, the matrix associated, and the freely dissolved, was obtained by subtracting the AgNP content from the total silver content that was determined by ICPMS after digestion. The limits of quantification (S/N = 10) for antibacterial products were 0.4 μg/kg and 0.2 μg/kg for AgNPs and total silver, respectively. The reliable quantification limit was 3 μg/kg for total Ag +. The presence of Ag + at concentrations up to 2-fold that of AgNPs caused no effects on the determination of AgNPs. In the cloud point extraction of AgNPs in antibacterial products, the spiked recoveries of AgNPs were in the range of 71.7-103% while the extraction efficiencies of Ag + were in the range of 1.2-10%. The possible coextracted other silver containing nanoparticles in the cloud point extraction of AgNPs were distinguished by transmission electron microscopy (TEM), scanning electron microscopy (SEM)- energy dispersive spectroscopy (EDS), and UV-vis spectrum. Real sample analysis indicated that even though the manufacturers claimed nanosilver products, AgNPs were detected only in three of the six tested antibacterial products. © 2011 American Chemical Society.


Qi W.,CAS Research Center for Eco Environmental Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences | Pernet-Coudrier B.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Qu J.,CAS Research Center for Eco Environmental Sciences
Environmental Science and Pollution Research | Year: 2013

In this study, surface water samples from the Wenyu River and the North Canal, effluent from major wastewater treatment plants (WWTPs) in Beijing, and wastewater from open sewers that discharge directly into the river system were collected and analyzed for 16 priority USEPA polycyclic aromatic hydrocarbons (PAHs). Concentrations of these 16 PAHs ranged from 193 to 1790 ng/L in river surface waters, 245 to 404 ng/L in WWTP effluents, and 431 to 2860 ng/L in the wastewater from the small sewers. The WWTP effluent was the main contributor of dissolved PAHs to the river, while wastewater from the small sewers contributed both dissolved and suspended particulate matter-associated PAH to the river as indicated by the high dissolved organic carbon and suspended particulate matter contents in the wastewater. Although the flow from each open sewer was small, a PAH discharge as high as 44 kg/year could occur into the river from these types of sewers. This amount was equivalent to about 22 % of the PAH loads discharged into the North Canal downstream from Beijing, whereas the remainder was mainly released by the major WWTPs in Beijing. © 2013 Springer-Verlag Berlin Heidelberg.


Hou Y.,CAS Research Center for Eco Environmental Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences | Zhao X.,CAS Research Center for Eco Environmental Sciences | Qu J.,CAS Research Center for Eco Environmental Sciences | Chen J.P.,National University of Singapore
Journal of Colloid and Interface Science | Year: 2012

Hexavalent chromium is one of the most toxic heavy metals in aqueous solutions. It has been well documented that the brown seaweed can be used as a promising biosorbent for the sequestration of this heavy metal from wastewater. However, the uptake of Cr(VI) is reportedly a rather slower process; the sorption equilibrium can only be established after a few days, much slower than a few hours for the trivalent chromium ion. In this study, we developed a novel technology of electrochemically assisted biosorption (ECAB) system for the enhancement of the treatment efficiency. It was found through our study that the removal efficiencies of Cr(VI) and total chromium were greatly enhanced by 48.1% and 51.3%, respectively, with the application of -1.0V in the ECAB system. The conversion of Cr(III) due to the electroreduction of Cr(VI) and the higher pH due to the cathodic H2 evolution created a favorable condition for the uptake of chromium onto the modified seaweed (MSW). The reduction and adsorption of Cr(VI) by MSW was proved to play a minor role in the removal. Both direct electroreduction and indirect electroreduction by atomic H* contributed to the reduction of Cr(VI). © 2012 Elsevier Inc.


Fan Z.,Peking University | Hu J.,Peking University | An W.,CAS Research Center for Eco Environmental Sciences | Yang M.,CAS Research Center for Eco Environmental Sciences
Environmental Science and Technology | Year: 2013

This study applied a sensitive dansylation LC-MS/MS method to the investigation on the occurrence of bisphenol A (BPA), nonylphenol (NP), estrogens (E1 and E2), and their 11 chlorinated byproducts in 62 drinking water treatment plants (DWTPs) of 31 major cities across China. BPA (4.7-512 ng/L), NP (8.2-918 ng/L), and E1 (ND-9.9 ng/L) were widely detected in source waters, E2 was detected in less than half of the samples (ND-3.2 ng/L), while chlorinated byproducts were only detected in source waters of two DWTPs. In drinking water, chlorinated BPAs and monochloro-NP (MCNP) were detected in more than half of the samples with concentrations of 0.2-26.7 ng/L for monochloro-BPA (MCBPA), ND-6.3 ng/L for dichloro-BPA (DCBPA), ND-7.7 ng/L for trichloro-BPA (TCBPA), ND-4.8 ng/L for tetrachloro-BPA (TBBPA), and ND-13.3 ng/L for MCNP, while dichloro-E1 (DCE1, ND-0.2 ng/L) and dichloro-NP (DCNP, ND-1.6 ng/L) were less frequently detected (10/62 and 4/62). The production of chlorinated NPs in DWTPs was mainly influenced by the amount of NP in source water and chlorine added, while the concentrations of chlorinated BPAs in drinking waters were only found to be significantly correlated with those of BPA in source waters. Advanced treatment processes could be effective techniques for reducing target chlorinated byproducts in drinking water. This is the first report on the occurrence of chlorinated byproducts of BPA, NP, and estrogens in drinking water, and these chemicals should be considered when assessing the human risk of their parent compounds. © 2013 American Chemical Society.


Li J.,Beijing Normal University | Wang Z.,CAS Research Center for Eco Environmental Sciences | Ma M.,CAS Research Center for Eco Environmental Sciences | Peng X.,CAS Guangzhou Institute of Geochemistry
Bulletin of Environmental Contamination and Toxicology | Year: 2010

A battery of in vitro recombinant yeast bioassays was conducted to assess the estrogen receptor, androgen receptor, progesterone receptor and thyroid receptor ant/agonistic activities of effluents collected from Datansha wastewater treatment plant (WWTP), furthermore to evaluate the removal efficiencies of endocrine disrupting chemicals in the WWTP. The results showed that estrogenic, anti-androgenic, anti-progesteronic and anti-thyroidic activities were observed in influent. The removal efficiencies of these compounds were more than 80%, which suggested that the present wastewater treatment processes were good enough to remove most of all kinds of endocrine disruption chemicals. © Springer Science+Business Media, LLC 2010.


Chen W.,CAS Research Center for Eco Environmental Sciences | Hou Z.,Shihezi University | Wu L.,University of California at Riverside | Liang Y.,Shihezi University | Wei C.,Shihezi University
Agricultural Water Management | Year: 2010

In arid and semi-arid regions, salinity is a serious and chronic problem for agriculture. A 3-year field experiment in the arid environment of Xinjiang, northwest China, was conducted to study the salinity change in soil resulting from deficit irrigation of cotton with non-saline, moderate saline and high saline water. The salinity profile distribution was also evaluated by an integrated water, salinity, and nitrogen model, ENVIRO-GRO. The simulated and observed salinity distributions matched well. Results indicated that after 3 years of cotton production, the average salinity in the 1.0-m soil profile was 336% and 547% of the original soil profile, respectively, for moderate saline and high saline water irrigation. If the practices continued, the average soil salinity (ECe) in the 1.0-m soil profile would approach a steady level of 1.7, 10.8, and 14.7dSm-1, respectively, for the treatments receiving irrigation waters of 0.33, 3.62, and 6.71dSm-1. It was concluded that deficit irrigation of saline water in this region was not sustainable. Model simulation showed that a big flood irrigation after harvest can significantly reduce the salt accumulation in the soil profile, and that this practice was much more efficient for salinity control than applying the same extra amount of water during the growing season. © 2010 Elsevier B.V.


Gai C.,CAS Research Center for Eco Environmental Sciences | Liu Z.,CAS Research Center for Eco Environmental Sciences | Han G.,National University of Singapore | Peng N.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Bioresource Technology | Year: 2015

Thermogravimetric analysis and differential thermal analysis were employed to investigate combustion characteristics of two low-lipid microalgae, Chlorella pyrenoidosa (CP) and Spirulina platensis (SP) and iso-conversional Starink approach was used to calculate the kinetic parameters in the present study. The results showed that three stages of mass loss, including dehydration, devolatilization and char oxidation, were observed during combustion of both of two low-lipid microalgae. The whole weight loss of combustion of two microalgae was both shifted to higher temperature zones with increased heating rates from 10 to 40. K/min. In the 0.1-0.9 conversion range, the apparent activation energy of CP increased first from 51.96 to 79.53. kJ/mol, then decreased to 55.59. kJ/mol. Finally, it slightly increased to 67.27. kJ/mol. In the case of SP, the apparent activation energy gradually increased from 68.51 to 91.06. kJ/mol. © 2015 Elsevier Ltd.


Qi W.,CAS Research Center for Eco Environmental Sciences | Muller B.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Pernet-Coudrier B.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Singer H.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | And 3 more authors.
Science of the Total Environment | Year: 2014

Twenty percent of the water run-off from China's land surface drains into the Yangtze River and carries the sewage of approximately 400million people out to sea. The lower stretch of the Yangtze therefore offers the opportunity to assess the pollutant discharge of a huge population. To establish a comprehensive assessment of micropollutants, river water samples were collected monthly from May 2009 to June 2010 along a cross-section at the lowermost hydrological station of the Yangtze River not influenced by the tide (Datong Station, Anhui province). Following a prescreening of 268 target compounds, we examined the occurrence, seasonal variation, and annual loads of 117 organic micropollutants, including 51 pesticides, 43 pharmaceuticals, 7 household and industrial chemicals, and 16 polycyclic aromatic hydrocarbons (PAHs). During the 14-month study, the maximum concentrations of particulate PAHs (1-5μg/g), pesticides (11-284ng/L), pharmaceuticals (5-224ng/L), and household and industrial chemicals (4-430ng/L) were generally lower than in other Chinese rivers due to the dilution caused of the Yangtze River's average water discharge of approximately 30,000m3/s. The loads of most pesticides, anti-infectives, and PAHs were higher in the wet season compared to the dry season, which was attributed to the increased agricultural application of chemicals in the summer, an elevated water discharge through the sewer systems and wastewater treatment plants (WWTP) as a result of high hydraulic loads and the related lower treatment efficiency, and seasonally increased deposition from the atmosphere and runoff from the catchment. The estimated annual load of PAHs in the river accounted for some 4% of the total emission of PAHs in the whole Yangtze Basin. Furthermore, by using sucralose as a tracer for domestic wastewater, we estimate a daily disposal of approximately 47million m3 of sewage into the river, corresponding to 1.8% of its average hydraulic load. In summary, the annual amounts flushed by the Yangtze River into the East China Sea were 2.9×106tons of dissolved and particulate organic carbon (DOC and POC), 369tons of PAHs, 98tons of pesticides, 152tons of pharmaceuticals, and 273tons of household and industrial chemicals. While the concentrations seem comparably moderate, the pollutant loads are considerable and pose an increasing burden to the health of the marine coastal ecosystem. © 2013 Elsevier B.V.


Yu S.-J.,CAS Research Center for Eco Environmental Sciences | Yin Y.-G.,CAS Research Center for Eco Environmental Sciences | Chao J.-B.,China Institute of Metrology | Shen M.-H.,CAS Research Center for Eco Environmental Sciences | Liu J.-F.,CAS Research Center for Eco Environmental Sciences
Environmental Science and Technology | Year: 2014

The fast growing and abundant use of silver nanoparticles (AgNPs) in commercial products alerts us to be cautious of their unknown health and environmental risks. Because of the inherent redox instability of silver, AgNPs are highly dynamic in the aquatic system, and the cycle of chemical oxidation of AgNPs to release Ag+ and reconstitution to form AgNPs is expected to occur in aquatic environments. This study investigated how inevitable environmentally relevant factors like sunlight, dissolved organic matter (DOM), pH, Ca2+/Mg2+, Cl-, and S2- individually or in combination affect the chemical transformation of AgNPs. It was demonstrated that simulated sunlight induced the aggregation of AgNPs, causing particle fusion or self-assembly to form larger structures and aggregates. Meanwhile, AgNPs were significantly stabilized by DOM, indicating that AgNPs may exist as single particles and be suspended in natural water for a long time or delivered far distances. Dissolution (ion release) kinetics of AgNPs in sunlit DOM-rich water showed that dissolved Ag concentration increased gradually first and then suddenly decreased with external light irradiation, along with the regeneration of new tiny AgNPs. pH variation and addition of Ca2+ and Mg2+ within environmental levels did not affect the tendency, showing that this phenomenon was general in real aquatic systems. Given that a great number of studies have proven the toxicity of dissolved Ag (commonly regarded as the source of AgNP toxicity) to many aquatic organisms, our finding that the effect of DOM and sunlight on AgNP dissolution can regulate AgNP toxicity under these conditions is important. The fact that the release of Ag+ and regeneration of AgNPs could both happen in sunlit DOM-rich water implies that previous results of toxicity studies gained by focusing on the original nature of AgNPs should be reconsidered and highlights the necessity to monitor the fate and toxicity of AgNPs under more environmentally relevant conditions. © 2013 American Chemical Society.


Han L.,CAS Research Center for Eco Environmental Sciences | Zhou W.,CAS Research Center for Eco Environmental Sciences | Li W.,CAS Research Center for Eco Environmental Sciences | Li L.,Peking University
Environmental Pollution | Year: 2014

We examined and compared PM2.5 concentrations in urban and the surrounding regions, and further investigated the impact of urbanization on urban PM2.5 concentrations at the Chinese prefectures. Annual PM 2.5 concentrations in most prefectures were greater than 10 μg/m3, the air quality guideline of the World Health Organization. Those prefectures were mainly distributed along the east coast and southeast of Sichuan province; The urban PM2.5 concentrations (UrbanPM 2.5) in 85 cities were greater than (>10 μg/m3) those in the surrounding area. Those cities were mainly located in the Beijing-Sichuan and Shanghai-Guangxi belts. In addition, UrbanPM2.5 was less than (<0 μg/m3) that in surrounding areas in only 41 prefectures, which were located in western China or nearby mega cities; Significant positive correlations were found between UrbanPM2.5 and urban population (R2 = 0.99, P < 0.05), and between UrbanPM 2.5 and urban second industry fraction (R2 = 0.71, P < 0.05), suggesting that urbanization had considerable impact on PM2.5 concentrations. © 2014 Elsevier Ltd. All rights reserved.


He G.,University of California at Davis | Zhao B.,University of California at Davis | Zhao B.,CAS Research Center for Eco Environmental Sciences | Denison M.S.,University of California at Davis
Environmental Toxicology and Chemistry | Year: 2011

Leachate from rubber tire material contains a complex mixture of chemicals previously shown to produce toxic and biological effects in aquatic organisms. The ability of these leachates to induce Ah receptor (AhR)-dependent cytochrome P4501A1 expression in fish indicated the presence of AhR active chemicals, but the responsible chemicals and their direct interaction with the AhR signaling pathway were not examined. Using a combination of AhR-based bioassays, we have demonstrated the ability of tire extract to stimulate both AhR DNA binding and AhR-dependent gene expression and confirmed that the responsible chemicals were metabolically labile. The application of CALUX (chemical-activated luciferase gene expression) cell bioassay-driven toxicant identification evaluation not only revealed that tire extract contained a variety of known AhR-active polycyclic aromatic hydrocarbons but also identified 2-methylthiobenzothiazole and 2-mercaptobenzothiazole as AhR agonists. Analysis of a structurally diverse series of benzothiazoles identified many that could directly stimulate AhR DNA binding and transiently activate the AhR signaling pathway and identified benzothiazoles as a new class of AhR agonists. In addition to these compounds, the relatively high AhR agonist activity of a large number of fractions strongly suggests that tire extract contains a large number of physiochemically diverse AhR agonists whose identities and toxicological/biological significances are unknown. © 2011 SETAC.


Zhuang X.,CAS Research Center for Eco Environmental Sciences | Zhuang X.,Chinese Academy of Sciences | Han Z.,CAS Research Center for Eco Environmental Sciences | Han Z.,University of Chinese Academy of Sciences | And 3 more authors.
Environmental Pollution | Year: 2010

Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. © 2010 Elsevier Ltd. All rights reserved.


Liu Y.,Environment Canada | Liu Y.,CAS Research Center for Eco Environmental Sciences | Liggio J.,Environment Canada
Atmospheric Chemistry and Physics | Year: 2014

The mixed-phase relative rates approach for determining aerosol particle organic heterogeneous reaction kinetics is often performed utilizing mass spectral tracers as a proxy for particle-phase reactant concentration. However, this approach may be influenced by signal contamination from oxidation products during the experiment. In the current study, the mixed-phase relative rates technique has been improved by combining a positive matrix factor (PMF) analysis with electron ionization aerosol mass spectrometry (unit-mass resolution), thereby removing the influence of m / z fragments from reaction products on the reactant signals. To demonstrate the advantages of this approach, the heterogeneous reaction between OH radicals and citric acid (CA) was investigated using a photochemical flow tube coupled to a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS). The measured heterogeneous rate constant (k2) of citric acid toward OH was (3.31 ± 0.29) × 10−12 cm3 moleculeg'1 sg'1 at 298 K and (30 ± 3)% relative humidity (RH) and was several times greater than the results utilizing individual m / z fragments. This phenomenon was further evaluated for particulate-phase organophosphates (triphenyl phosphate (TPhP), tris-1,3-dichloro-2-propyl phosphate (TDCPP) and tris-2-ethylhexyl phosphate (TEHP)), leading to k2 values significantly larger than previously reported. The results suggest that heterogeneous kinetics can be significantly underestimated when the structure of the products is highly similar to the reactant and when a non-molecular tracer is measured with a unit-mass resolution aerosol mass spectrometer. The results also suggest that the heterogeneous lifetime of organic aerosol in models can be overestimated due to underestimated OH uptake coefficients. Finally, a comparison of reported rate constants implies that the heterogeneous oxidation of aerosols will be dependent upon a number of factors related to the reaction system, and that a single rate constant for one system cannot be universally applied under all conditions.


Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Hebei United University | Niu H.,CAS Research Center for Eco Environmental Sciences | Pan Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2011

In this article, C18/NH2 mixed group modified Fe3O4/SiO2 magnetic nanoparticles (Fe3O4/SiO2/C18+NH2 MNPs) were successfully synthesized and used for the extraction of perfluorinated compounds (PFCs) from large volume of water solution. The Fe3O4/SiO2/C18+NH2 MNPs, about 25nm in diameter, possess high extraction ability to the anionic organic pollutants due to the dual function of hydrophobic octadecyl group and cationic aminopropyl groups at low pH. More than 90% of the targets can be extracted from 500mL of water solution with 0.1g of the MNP sorbent at pH 3. Twenty min is sufficient to reach adsorption equilibrium, and the targets can be desorbed from the sorbent readily with 12mL of alkalized methanol after magnetic separation. Simplified extraction procedure could be achieved because of the superparamagnetism and high saturation magnetization of the sorbent (44emug-1). Therefore, preconcentration of trace level of PFCs from water solution can be performed by using this Fe3O4/SiO2/C18+NH2 MNP sorbent which are stable for multiple reuses. © 2011 Elsevier Inc.


Zeng T.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Hebei United University | Guo Y.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Journal of Materials Chemistry A | Year: 2014

Development of novel nanostructure gold-based catalysts with high performance and low cost is of a great scientific interest. Here, a new controllable coordination coating was facilely integrated onto gold nanoparticles (Au NPs) using low-cost natural polyphenols and ferric ions. Heat treatment, organic solvents, special instruments, or additive chemicals were not involved in the whole synthetic procedure. Due to the presence of the unique polyphenol-Fe3+ shell, the as-prepared catalyst showed an improved catalytic performance, pH-responsive character and good stability towards the reduction of 4-NP. © the Partner Organisations 2014.


Ma Y.,CAS Research Center for Eco Environmental Sciences | Niu H.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Hebei United University | Cai Y.,CAS Research Center for Eco Environmental Sciences
Analyst | Year: 2011

In this work, we propose a simple, sensitive and reliable assay for melamine in raw milk with dopamine-stabilized silver nanoparticles (AgNPs) as a colorimetric reader. Dopamine can reduce Ag + and functionalize the produced AgNPs to form monodispersed AgNPs. The coexisting melamine in reaction solution could bind dopamine through Michael addition and Schiff base reactions, which leads to the aggregation of AgNPs and induces a colorimetric response. The one-step assay is simple, rapid and highly sensitive. The color-change is quantitatively correlated with the concentration of melamine in the range of 10 ppb to 1.26 ppm, which is below the safety limit in China (1.0 ppm) and EU (2.0 ppm). The coexisting substances including phenylalanine, dl-leucine, l-glutamate, sulfanilic acid, Mg 2+, galactose, lysine, urea and glucose do not affect the determination of melamine. The colorimetric sensor can be used for rapid monitoring of raw milk quality. © 2011 The Royal Society of Chemistry.


Wang J.,CAS Nanjing Institute of Geography and Limnology | Wang J.,CAS Research Center for Eco Environmental Sciences | Shen J.,CAS Nanjing Institute of Geography and Limnology | Wu Y.,CAS Nanjing Institute of Soil Science | And 7 more authors.
ISME Journal | Year: 2013

Increasing evidence has emerged for non-random spatial distributions of microbes, but knowledge of the processes that cause variation in microbial assemblage among ecosystems is lacking. For instance, some studies showed that deterministic processes such as habitat specialization are important, while other studies hold that bacterial communities are assembled by stochastic forces. Here we examine the relative influence of deterministic and stochastic processes for bacterial communities from subsurface environments, stream biofilm, lake water, lake sediment and soil using pyrosequencing of the 16S ribosomal RNA gene. We show that there is a general pattern in phylogenetic signal in species ecological niches across recent evolutionary time for all studied habitats, enabling us to infer the influences of community assembly processes from patterns of phylogenetic turnover in community composition. The phylogenetic dissimilarities among-habitat types were significantly higher than within them, and the communities were clustered according to their original habitat types. For communities within-habitat types, the highest phylogenetic turnover rate through space was observed in subsurface environments, followed by stream biofilm on mountainsides, whereas the sediment assemblages across regional scales showed the lowest turnover rate. Quantifying phylogenetic turnover as the deviation from a null expectation suggested that measured environmental variables imposed strong selection on bacterial communities for nearly all sample groups. For three sample groups, spatial distance reflected unmeasured environmental variables that impose selection, as opposed to spatial isolation. Such characterization of spatial and environmental variables proved essential for proper interpretation of partial Mantel results based on observed beta diversity metrics. In summary, our results clearly indicate a dominant role of deterministic processes on bacterial assemblages and highlight that bacteria show strong habitat associations that have likely emerged through evolutionary adaptation. © 2013 International Society for Microbial Ecology All rights reserved.


Zeng T.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Hebei United University | Ma Y.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Chemical Communications | Year: 2013

A novel rattle-type sorbent with a surface-modified interior cavity and a magnetic Fe3O4-C double-layered shell was synthesized and first applied for magnetic solid-phase extraction. © 2013 The Royal Society of Chemistry.


Wang H.-F.,CAS Research Center for Eco Environmental Sciences | MacGregor-Fors I.,Institute Ecologia | Lopez-Pujol J.,University of Barcelona
Plant Ecology | Year: 2012

Urbanization is one of the most environmentally damaging of human activities, producing large alterations in ecosystem structure, function, species composition and interactions. In this study, we performed a systematic investigation of the plant species richness and density in the city of Beijing, China. We also assessed which socio-economic factors have most influence on plant diversity. Within the city, we found 551 plant species of 313 genera and 103 families, of which 118 were trees, 99 shrubs, and 296 herbs. Nearly half (48. 3 %) of the total plant species were aliens. Species richness and density were positively correlated both for tree/shrub and herb taxa, which indicate that although some species predominate in our study area, there is an important array of species in relation to their densities. As expected, most of the socio-economic variables studied showed to be related to at least one of the four plant diversity variables (i. e., herb richness, herb density, tree/shrub richness, and tree/shrub density). Land-use showed a significant relationship in all four cases, which generally had lower values in cultural and education areas (areas that in Beijing are generally characterized by large extensions of urbanized land). The year of establishment was also largely related to plant diversity, with higher values for recently developed areas. This was an expected result given the dynamics of the urban development of Beijing during the last 60 years, which consisted of intense urban sprawling, followed by more environmentally-friendly urbanization practices during the 2000s related to the greening of the city for the olympic games. This dynamics also explained the negative relationship found between the distance to the city center and both tree/shrub species richness and density. © 2012 Springer Science+Business Media B.V.


Zuo X.,Nanjing University of Information Science and Technology | Liu Z.,CAS Research Center for Eco Environmental Sciences | Chen M.,Nanjing University of Information Science and Technology
Bioresource Technology | Year: 2016

This study investigated effect of H2O2 concentrations on copper removal using H2O2 modified hydrothermal carbonization Cymbopogon schoenanthus L. Spreng (HLG). Sorption behaviors of Cu (II) on the modified HLG by 20% H2O2 (mHLG2) could be the most desirable. Based on Langmuir isotherm, the maximum amount of Cu (II) uptake was in the sequence of mHLG2 (53.8 mg g-1) > mHLG1 (44.2 mg g-1) > mHLG3 (42.0 mg g-1) > mHLG0 (35.8 mg g-1), which was higher than the results from majority of previous studies, suggesting that H2O2 modification advanced sorption capacity of hydrothermal biochars evidently. Effect mechanisms exploration indicated that the difference of Cu (II) removal by biochars before and after the modification was mainly related to functional groups. Carboxylic group was responsible for the best sorption property of Cu (II) by mHLG2, which was attributed to its significant relationships with H2O2 modification and Cu (II) removal. © 2016 Elsevier Ltd.


Zeng T.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,Hebei United University | Niu H.-Y.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Applied Catalysis B: Environmental | Year: 2013

A simple and green method for the deposition of gold nanoparticles (Au NPs) on the surface of polydopamine (PDA)-encapsulated Fe3O4 nanoparticles is proposed to fabricate a core-shell Fe3O4@PDA-Au nanocatalyst. In the current approach, Fe3O4 core, about 400nm in diameter, is enveloped in a PDA coating with a thickness of about 45nm on which plenty of small Au NPs are immobilized subsequently. PDA serves as a reductant as well as a stabilizer so that additional reagents and thermo treatment are not necessary. In addition, both the size of Au NPs and the thickness of PDA layer are tunable to load more Au NPs with appropriate size on the PDA coating. The Au content on Fe3O4@PDA-Au nanocomposites is about 4.3wt.%, which endows the nanocatalyst with high catalytic performance in the reduction of o-nitroaniline to benzenediamine by NaBH4 (with a conversion of 99% in 7min). Most importantly, the catalyst can be easily recycled by using an external magnetic field due to the high magnetization (39.6emug-1) and shows excellent reusability (8 cycles with a conversion of >98% for o-nitroaniline). The as-prepared catalyst also show good activity for the reduction of other nitrobenzene analogs. These facilitate the practical application of the catalyst in reduction of nitroaromatic compounds. © 2013 Elsevier B.V.


Pan G.,CAS Research Center for Eco Environmental Sciences | Chen J.,CAS Yantai Institute of Coastal Zone Research | Anderson D.M.,Woods Hole Oceanographic Institution
Harmful Algae | Year: 2011

A new method was developed for marine harmful algal bloom (HAB) mitigation using local beach sand or silica sand modified with chitosan and polyaluminum chloride (PAC). Untreated sand was ineffective in flocculating algal cells, but 80% removal efficiency was achieved for Amphidinium carterae Hulburt and Chlorella sp. in 3min (t80=3min) using 120mgL-1 sand modified with 10mgL-1 PAC and 10mgL-1 chitosan. After several hours 92-96% removal was achieved. The t80 for removing A. carterae using the modifiers only (PAC and chitosan combined) was 60min and for Chlorella sp. 120min, which are much slower than with the corresponding modified sand. Sands were critical for speeding up the kinetic processes of flocculation and sedimentation of algal flocs. PAC was helpful in forming small flocs and chitosan is essential to bridge the small flocs into large dense flocs. Chitosan was also important in inhibiting the escape of cells from the flocs. Chitosan and PAC used together as modifiers make it possible to use local beach sands for HAB mitigation in seawater. Economical and environmental concerns could be reduced through the use of sands and biodegradable chitosan, but the potential impacts of PAC need further study. © 2011 Elsevier B.V.


Liu Y.,Environment Canada | Liu Y.,CAS Research Center for Eco Environmental Sciences | Huang L.,Environment Canada | Li S.-M.,Environment Canada | And 2 more authors.
Atmospheric Chemistry and Physics | Year: 2014

A particle-phase relative rates technique is used to investigate the heterogeneous reaction between OH radicals and tris-2-butoxyethyl phosphate (TBEP) at 298K by combining aerosol time-of-flight mass spectrometry (C-ToFMS) data and positive matrix factor (PMF) analysis. The derived second-order rate constants (k2) for the heterogeneous loss of TBEP is (4.44 ± 0.45)× 10-12 cm3 molecule-1 s-1, from which an approximate particle-phase lifetime was estimated to be 2.6 (2.3-2.9) days. However, large differences in the rate constants for TBEP relative to a reference compound were observed when comparing internally and externally mixed TBEP/organic particles, and upon changes in the RH. The heterogeneous degradation of TBEP was found to be depressed or enhanced depending upon the particle mixing state and phase, highlighting the complexity of heterogeneous oxidation in the atmosphere. The effect of gas-particle partitioning on the estimated overall lifetime (gas + particle) for several organophosphate esters (OPEs) was also examined through the explicit modeling of this process. The overall atmospheric lifetimes of TBEP, tris-2-ethylhexyl phosphate (TEHP) and tris-1,3-dichloro-2-propyl phosphate (TDCPP) were estimated to be 1.9, 1.9 and 2.4 days respectively, and are highly dependent upon particle size. These results demonstrate that modeling the atmospheric fate of particle-phase toxic compounds for the purpose of risk assessment must include the gas-particle partitioning process, and in the future include the effect of other particulate components on the evaporation kinetics and/or the heterogeneous loss rates. © Author(s) 2014.


Ma Y.-R.,CAS Research Center for Eco Environmental Sciences | Niu H.-Y.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,Hebei United University | Cai Y.-Q.,CAS Research Center for Eco Environmental Sciences
Chemical Communications | Year: 2011

A facile, economic and eco-friendly colorimetric sensor for Cu 2+ using dopamine/silver nanoparticles was developed. The sensor shows excellent sensitivity and selectivity toward Cu 2+ in the range of 3.2-512 ppb and can be applied for Cu 2+ detection in tap water. © The Royal Society of Chemistry 2011.


Zhang D.,CAS Research Center for Eco Environmental Sciences | Zhang D.,Northwest University, China | Niu H.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Journal of Hazardous Materials | Year: 2011

In this work, environmentally friendly magnetite nanoparticles (Fe 3O 4 MNPs) were used to adsorb chlorotetracycline (CTC) from aqueous media. Fe 3O 4 MNPs exhibit ultrahigh adsorption ability to this widely used antibiotic. The adsorption behavior of CTC on Fe 3O 4 MNPs fitted the pseudo-second-order kinetics model, and the adsorption equilibrium was achieved within 10h. The maximum Langmuir adsorption capacity of CTC on Fe 3O 4 (476mgg -1) was obtained at pH 6.5. Thermodynamic parameters calculated from the adsorption data at different temperature showed that the adsorption reaction was endothermic and spontaneous. Low concentration of NaCl and foreign divalent cations hardly affected the adsorption. Negative effect of coexisting humic acid (HA) on CTC adsorption was also observed when the concentration of HA was lower than 20mgL -1. But high concentration of HA (>20mgL -1) increased the CTC adsorption on Fe 3O 4 MNPs. The matrix effect of several environmental water samples on CTC adsorption was not evident. Fe 3O 4 MNPs were regenerated by treatment with H 2O 2 or calcination at 400°C in N 2 atmosphere after separation from water solution by an external magnet. This research provided a high efficient and reusable adsorbent to remove CTC selectively from aqueous media. © 2011 Elsevier B.V.


Liu R.,CAS Research Center for Eco Environmental Sciences | Liu J.-F.,CAS Research Center for Eco Environmental Sciences | Zhang Z.-M.,CAS Research Center for Eco Environmental Sciences | Zhang L.-Q.,China University of Petroleum - Beijing | And 3 more authors.
Journal of Physical Chemistry Letters | Year: 2014

For their unique properties, core-shell bimetal nanostructures are currently of immense interest. However, their synthesis is not a trivial work, and most works have been conducted on nanoparticles. We report herein a new synthetic tactic for submonolyer-Pt coated ultrathin Au nanowires (NWs). Besides providing a strong electromagnetic field for Raman signal enhancing, the underlined Au NWs markedly enhanced the catalytic activity of Pt atoms through increasing their dispersity and altering their electronic state. The integration of excellent SERS and high catalytic activity within Au@Pt NWs enable it work as platform for catalyzed reaction study. As a proof of principle, the self-organized Au@Pt NWs thin film is employed in operando SERS monitoring of the p-nitrothiophenol reduction process. In addition to providing kinetic data for structure-activity relationship study, the azo-intermidate independent path is also directly witnessed. This synthetic tactic can be extended to other metals, thus offering a general approach to modulate the physical/chemical properties of both core and shell metals. © 2014 American Chemical Society.


Sun M.,CAS Research Center for Eco Environmental Sciences | Kim G.,Kyungpook National University
Journal of Hydrologic Engineering | Year: 2016

An empirical statistical system for quantitative forecasting of monthly precipitation in Korea has been developed using the cyclostationary empirical orthogonal function s(CSEOF) and the canonical correlation analysis (CCA) with sea surface temperature (SST) data as the predictor. Monthly Korean precipitation and SST data are comprehensively analyzed using the empirical orthogonal function (EOF) technique and the CSEOF technique, respectively, and the CSEOF technique can exhibit the spatial distribution and temporal evolution characteristics of variability along with recurrent seasons of precipitation in Korea. Through a multivariate regression method, the CCA technique is used to forecast precipitation with different lead times, and the forecasting results indicate that the CSEOF-CCA forecasting model agrees well with the observation data and is particularly useful in forecasting seasonal precipitation variations in Korea. © 2015 American Society of Civil Engineers.


Zeng T.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Hebei United University | Wang S.,Northeast Normal University | And 3 more authors.
Journal of Materials Chemistry A | Year: 2013

A facile method is proposed to fabricate yolk-shell microspheres consisting of a movable silica core, a multifunctional double-layered shell, and plenty of tiny gold nanoparticles (Au NPs, ∼2 nm) confined within the interior cavity and the mesoporous shell. The presented strategy involves the one-step coating of a Fe3O4/carbon double-layered shell, the partial etching of the silica cores and the in situ immobilization of Au NPs. The inner Fe3O4 layer of the double-layered shell endows the composites with superparamagnetism and thereby simplifies the introduction procedure of a magnetic component. The outer carbon layer not only protects the Fe3O4 layer from outside harsh conditions but also provides additional adsorption sites for Au NPs besides the interior space. The large number of catalytic active sites together with the advantages of the yolk-shell architecture make the nanocomposite a perfect catalyst for the reduction of 4-nitrophenol to 4-aminophenol in the presence of NaBH4 (TOF value is 17.4 min-1). Moreover, the synthesized catalyst can be easily recovered and reused for at least nine cycles due to its magnetically separable feature and good stability. These confirm that the as-prepared yolk-like nanocomposites are promising candidates for catalytic application. © 2013 The Royal Society of Chemistry.


Zeng T.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Hebei United University | Wang S.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Chemistry - A European Journal | Year: 2014

Conventional solid catalysts for heterogeneous Fenton-like reactions in bulk solution usually suffer from aggregation and vulnerability, which greatly lower the catalytic efficiency and hamper their practical application. Herein, we demonstrate a promising yolk-shell nanostructure with both the core and the shell composed of magnetite (designated as yolk-like Fe3O 4@Fe3O4/C) as a nanoreactor capable of accommodating the Fenton-like reaction into its void space. Benefiting from the mesoporous shell and perfect interior cavity of this composite, reactants can access and be abundantly confined within the microenvironment where Fe 3O4 sites are dispersed on the entire cavity surfaces, thus leading to a higher catalytic efficiency compared with the conventional solid catalysts in bulk solution. The chosen model reaction of chlorophenols degradation in the presence of the as-prepared materials as well as hydrogen peroxide (H2O2) confirms this assumption. Under the optimal reaction conditions, more than 97 % 4-chlorophenol (4-CP) can be degraded in the Fe3O4@Fe3O4/C nanoreactor, whereas only 28 % can be achieved by using bare Fe 3O4 particles within 60min. Furthermore, owing to the existence of the outermost carbon layer and high-magnetization properties, the nanoreactor can be re-used for several runs. The synthesized nanoreactor displays superior catalytic activity toward the Fenton-like reaction compared with the bare solid catalysts, and thereby holds significant potential for practical application in environmental remediation. An unconventional shell: A novel yolk-shell nanostructure in which both the core and the shell are composed of magnetite (designated as yolk-like Fe3O4@Fe 3O4/C) functions as a nanoreactor for the Fenton-like reaction, displaying enhanced catalytic activity compared with conventional solid catalysts (see figure). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang S.,CAS Research Center for Eco Environmental Sciences | Zhang S.,Ludong University | Niu H.,CAS Research Center for Eco Environmental Sciences | Zhang Y.,Ludong University | And 5 more authors.
Journal of Chromatography A | Year: 2012

In this work, phosphatidylcholine (PC) was coated on magnetic nanoparticles to form lipid bilayer as solid-phase extraction (SPE) sorbents for the enrichment of polycyclic aromatic hydrocarbons (PAHs) from environmental water and milk samples. The lipid bilayer was coated on Fe 3O 4 nanoparticles using a modified dry lipid film hydration method. The resulted Fe 3O 4/PC could be readily isolated from solution with a magnet, and exhibited excellent adsorption performance to organic pollutants. Only 0.1g of sorbents was enough to extract PAHs from 500mL aqueous solution, and 6mL of acetonitrile was required to desorb them. The method was fast and relied on 10min extraction time and 5min magnetic separation. The proposed method was successfully applied to determine PAHs in some environmental water and milk samples. The detection limit was in the range of 0.2-0.6ngL -1. The recoveries of the spiked water samples ranged from 89% to 115% with relative standard deviations (RSD) varying from 1% to 8%. For spiked milk samples, RSD was satisfactory (1-9%), but the recoveries were relatively low (42-62%). We show the potentials of Fe 3O 4/PC sorbents in environmental water and biological sample analyses. © 2012 Elsevier B.V.


Ma Y.-R.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,Hebei United University | Zeng T.,CAS Research Center for Eco Environmental Sciences | And 5 more authors.
ACS Applied Materials and Interfaces | Year: 2013

Polydopamine-coated Fe3O4 nanoparticles (Fe 3O4@PDA NPs) were synthesized and applied as matrix for the detection of pollutants by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The synthesis of Fe 3O4@PDA NPs was accomplished in 30 min by in situ polymerization of dopamine without any toxic reagent. Using Fe3O 4@PDA NPs as matrix of MALDI-TOF, eleven small molecule pollutants (molecular weight from 251.6 to 499.3), including Benzo(a)pyrene (BaP), three perfluorinated compounds (PFCs), and seven antibiotics, were successfully detected in either positive or negative reflection mode without background interference. Furthermore, the Fe3O4@PDA NPs can also enrich trace amounts of hydrophobic target, such as BaP, from solution to nanoparticles surface. Then the Fe3O4@PDA-BaP can be isolated through magnetic sedimentation step and directly spotted on the stainless steel plate for MALDI measurement. With Fe3O 4@PDA NPs as adsorbent and matrix, we also realized the analysis of BaP in tap water and lake water samples. Thus, a magnetic solid-phase extraction (MSPE)-MALDI-TOF-MS method was established for the measurement of BaP. © 2013 American Chemical Society.


Zhang X.-L.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,Hebei United University | Niu H.-Y.,CAS Research Center for Eco Environmental Sciences | Li W.-H.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemical Communications | Year: 2011

C18-functionalized mesoporous silica shell was successfully fabricated on the surface of an Fe3O4/SiO2 core to obtain an Fe3O4/SiO2/SiO2-C 18 magnetic microsphere. The microsphere exhibited high extraction efficiency to organic targets and strong anti-interference ability to natural organic matter. It could be easily isolated from water solution after extraction. © 2011 The Royal Society of Chemistry.


Zhang M.,CAS Research Center for Eco Environmental Sciences | Chen H.,CAS Research Center for Eco Environmental Sciences | Wang J.,North China University of Water Conservancy and Electric Power | Pan G.,CAS Research Center for Eco Environmental Sciences
Journal of Environmental Sciences | Year: 2010

The characteristics of urban runoffs and their impact on rainwater utilization and storm pollution control were investigated in three different functional areas of Zhengzhou City, China. The results showed that in the same rain event the pollutant loads (chemical oxygen demand (COD) and total suspended solids (TSS)) in the sampling areas were in the order of industrial area > commercial area > residential area, and within the same area the COD and TSS concentrations of road runoffs were higher than those of roof runoffs. The first flush effects in roof and road runoffs were observed, hence the initial rainwater should be treated separately to reduce rainwater utilization cost and control storm pollution. The initial roof rainfall of 2 mm in residential area, 5 mm in commercial area and 10 mm in industrial area, and the initial road rainfall of 4 mm in residential area and all the road rainfall in commercial and industrial areas should be collected and treated accordingly before direct discharge or utilization. Based on the strong correlation between COD and TSS (R2, 0.87-0.95) and the low biodegradation capacity (biochemical oxygen demand BOD5/COD < 0.3), a sedimentation process and an effective filtration system composed of soil and slag were designed to treat the initial rainwater, which could remove over 90% of the pollutant loads. The above results may help to develop better rainwater utilization and pollution control strategies for cities with water shortages. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.


Niu H.,CAS Research Center for Eco Environmental Sciences | Wang S.,CAS Research Center for Eco Environmental Sciences | Wang S.,Northeast Normal University | Zhou Z.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Analytical Chemistry | Year: 2014

In this work, we have developed a novel sensing strategy employing mixed poly(ethylene glycol)-terminated (PEG-thiols) and perfluoroalkyl-terminated (F-thiols) alkanethiols modified gold nanoparticles (Au@PEG-F NPs) as a probe to detect perfluorinated compounds (PFCs) from water samples. PEG-thiols with high density and long carbon chains make the Au NPs probe well-dispersed in solution and stable even in high concentration of salt solution; F-thiols provide specific fluorous-fluorous interactions to PFCs, which results in adsorption of PFCs on Au@PEG-F NPs. The adsorbed PFCs cause the aggregation of Au@PEG-F NPs probes and thus induce the insolubility of probes and precipitation directly from reaction solution due to the superhydrophobicity of perfluorocarbon monolayers, leading to color and absorbance response of the assay to PFCs. The preparation of the Au@PEG-F NPs probe is very simple, and the colorimetric assay based on this mechanism for the detection of PFCs is selective and convenient. Combined with UV-vis spectrophotometry, the assay demonstrates good sensitivities to PFCs with wide linear range. In the designed concentration range, the response of the colorimetric assay to long-chain PFCs (perfluoroalkyl chain ≥7) is discerned even as the concentration of these PFCs is as low as 10 μg L-1. This low-cost and sensitive assay shows great potential to measure total PFCs in water samples. To the best of our knowledge, this is the first application of the specific fluorous-fluorous interactions and Au NPs based probes for colorimetric recognition for PFCs. © 2014 American Chemical Society.


Zeng T.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,CAS Research Center for Eco Environmental Sciences | Zhang X.-L.,Hebei United University | Ma Y.-R.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Journal of Materials Chemistry | Year: 2012

A facile, economical, and low-toxicity approach was proposed to coat gold nanoparticles (Au NPs) on the surface of graphene-encapsulated magnetic microspheres. The current method makes it possible to integrate Fe 3O 4 NPs and metal NPs with graphene without any interference or site competition. Dopamine serves as a reducing agent as well as a coupling agent for the assembly of reduced graphene oxide (RGO) and Au NPs on magnetic cores, so that no additional chemicals and thermal treatments are needed. The X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) results demonstrate that GO is successfully deoxygenated by the reduction of the PDA layer, while transmission electron microscopy (TEM), scanning electron microscopy (SEM), and inductively coupled plasma mass spectrometry (ICP-MS) results indicate that plenty of Au NPs (about 7.3 nm in diameter) are homogeneously distributed onto the surface of RGO and the Au content of the composite is 13.58 wt%. The high Au content endows the nanocatalyst with great catalytic performance towards the reduction of o-nitroaniline to benzenediamine by NaBH 4 (completely transformation within 4 min). Furthermore, the as-prepared catalyst can be easily recovered and reused at least ten times due to the high magnetization and stability. © 2012 The Royal Society of Chemistry.


Chen L.,CAS Research Center for Eco Environmental Sciences | Sun R.,CAS Research Center for Eco Environmental Sciences | Liu H.,Beijing Yongdinghe Water Resources Administrative Bureau
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

Urbanization refers to a process in which an increasing proportion of an entire population lives in cities and the suburbs of cities. A primary goal of urbanization is to develop a harmonious region between natural landscapes and human habitation. However, urbanized ecosystems and urban human populations are expanding around the world, causing many negative environmental effects, such as traffic jams, resource shortage, environmental pollution, and ecological degradation. Therefore, urban landscape changes and their eco-environmental effects have been received lots of attentions from researchers, managers, and the public. This paper presents a comprehensive review of researches on urban landscape changes and their eco-environmental effects. These eco-environmental effects identified in this study include urban heat island effect, air pollution, water issues, destruction of habitats, ecosystem service changes, and so on. The paper points out problems in current studies of urban landscape patterns: (1) Current studies are mainly implemented on the development and application of quantitative indices to quantify landscape pattern changes, whereas few has focused on the impacts of landscape pattern changes on the regional ecological security; (2) Although more recent efforts have been attempted to study the relationship between urban heat island effect and landscape pattern changes, relatively less results is available to explain the thermal mechanism of urban heat island effects; (3) Most studies focus on the effect of urban green landscape on air pollutant absorption, air particle retard, the comprehensive effects of urban landscape change on atmospheric quality and dust haze effect, are however less studied;(4) Attempts have been made to study urban ecological land uses to improve regional ecological security, but quantitative guidelines in relation to the landscape planning is also needed more integrated efforts among different disciplines. We suggest that more efforts should be implemented on integrating spatial data in multiple scales to reveal the environmental effects of landscape changes and their physical mechanisms. Moreover, multi-objective spatial optimization model for ecological land-use allocation should be developed by integrating the models of urban sprawl and ecosystem service evaluation.


Chen J.,Florida International University | Chen J.,CAS Research Center for Eco Environmental Sciences | Qin J.,Florida International University | Zhu Y.-G.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Applied and Environmental Microbiology | Year: 2013

Accumulation of arsenic has potential health risks through consumption of food. Here, we inserted the arsenite [As(III)] S-adenosylmethionine methyltransferase (ArsM) gene into the chromosome of Pseudomonas putida KT2440. Recombinantbacteria methylate inorganic arsenic into less toxic organoarsenicals. This has the potential for bioremediation of environmental arsenic and reducing arsenic contamination in food. © 2013, American Society for Microbiology.


Hao Z.,University of Burgundy | Hao Z.,China Agricultural University | Hao Z.,CAS Research Center for Eco Environmental Sciences | Fayolle L.,University of Burgundy | And 5 more authors.
Journal of Experimental Botany | Year: 2012

The ectoparasitic dagger nematode (Xiphinema index), vector of Grapevine fanleaf virus (GFLV), provokes gall formation and can cause severe damage to the root system of grapevines. Mycorrhiza formation by Glomus (syn. Rhizophagus) intraradices BEG141 reduced both gall formation on roots of the grapevine rootstock SO4 (Vitis berlandieri×V. riparia) and nematode number in the surrounding soil. Suppressive effects increased with time and were greater when the nematode was post-inoculated rather than co-inoculated with the arbuscular mycorrhizal (AM) fungus. Using a split-root system, decreased X. index development was shown in mycorrhizal and non-mycorrhizal parts of mycorrhizal root systems, indicating that both local and systemic induced bioprotection mechanisms were active against the ectoparasitic nematode. Expression analyses of ESTs (expressed sequence tags) generated in an SSH (subtractive suppressive hybridization) library, representing plant genes up-regulated during mycorrhiza-induced control of X. index, and of described grapevine defence genes showed activation of chitinase 1b, pathogenesis-related 10, glutathione S-transferase, stilbene synthase 1, 5-enolpyruvyl shikimate-3-phosphate synthase, and a heat shock proein 70-interacting protein in association with the observed local and/or systemic induced bioprotection against the nematode. Overall, the data suggest priming of grapevine defence responses by the AM fungus and transmission of a plant-mediated signal to non-mycorrhizal tissues. Grapevine gene responses during AM-induced local and systemic bioprotection against X. index point to biological processes that are related either to direct effects on the nematode or to protection against nematode-imposed stress to maintain root tissue integrity. © 2012 The Author.


Hou D.,CAS Research Center for Eco Environmental Sciences | Wang J.,CAS Research Center for Eco Environmental Sciences | Sun X.,University of Connecticut | Ji Z.,CAS Research Center for Eco Environmental Sciences | Luan Z.,CAS Research Center for Eco Environmental Sciences
Journal of Membrane Science | Year: 2012

The polyvinylidene fluoride (PVDF) composite hydrophobic hollow fiber membranes were fabricated for membrane distillation through non-solvent induced phase inversion by dispersing hydrophobic modified calcium carbonate nano-particles in the PVDF casting solution and using the mixture of LiCl and polyethylene glycol (PEG) as non-solvent additive. The influence of nano-particles on the spun hollow fiber membrane characteristics was investigated. The addition of hydrophobic nano-particles could optimize the sandwich-like morphology, narrow the pore size distribution, improve the membrane porosity and increase the membrane surface roughness and contact angle to some extent. The nano-particles also enhanced the crystallinity degree and thermal stability of the hollow fiber. In addition, the composite membranes presented stronger mechanical properties compared to the fiber without particles. During the desalination process of 3.5wt% sodium chloride solution, the maximum transmembrane permeate flux about 46.3kg/m 2h with a lower thermal loss was obtained from the composite fiber when the hot feed inlet temperature and the cold distillate inlet temperature were at 80.5°C and 20.0°C, respectively. Furthermore, the composite membrane exhibited satisfying performance stability compared with the pure PVDF membrane in the 30 days continuous desalination experiments, indicating that the as-spun composite fiber may be of great potential to be utilized in MD process for desalination. © 2012 Elsevier B.V.


Liu R.,CAS Research Center for Eco Environmental Sciences | Liu J.-F.,CAS Research Center for Eco Environmental Sciences | Zhou X.-X.,CAS Research Center for Eco Environmental Sciences | Sun M.-T.,CAS Institute of Physics | Jiang G.-B.,CAS Research Center for Eco Environmental Sciences
Analytical Chemistry | Year: 2011

Due to its demonstrated usefulness in fields such as trace analysis, biodiagnosis, and in vivo study, surface-enhanced Raman scattering (SERS) has received renewed interest in recent years. Development of SERS substrates is of great importance as the SERS intensity and reproducibility depend strongly on the SERS substrates. In this paper we report the fabrication of Au nanoporous film (NPFs) by self-organization of networked ultrathin Au nanowires for use as SERS substrates. The acquired Au NPFs display controllable thickness, low relative density, and considerable specific surface area. Furthermore, this self-organization of nanowires not only provides abundant junctions between nanowires, 5-20 nm nanopores, and three-dimensional nanowells, but also makes nanopores/nanogaps down to 1-2 nm. These nanoscale characteristics result in a high spatial density of hotspots with Raman enhancement factors up to 10 9. Combined with the uniformity and high purity, our Au NPF provides high-quality substrates for SERS sensing. © 2011 American Chemical Society.


Wu N.,CAS Research Center for Eco Environmental Sciences | Qiao M.,CAS Research Center for Eco Environmental Sciences | Zhang B.,Shandong Agricultural University | Cheng W.-D.,Jiaxing Academy of Agricultural science | And 2 more authors.
Environmental Science and Technology | Year: 2010

Tetracyclines are commonly used antibiotics in the swine industry for disease treatment and growth promotion. Tetracycline resistance was determined in soils sampled from farmlands in the vicinity of nine swine farms located in three cities in China. Totally, 15 tetracycline resistance (tet) genes were commonly detected in soil samples, including seven efflux pump genes (tetA, tetC, tetE, tetG, tetK, tetL, tetA/P), seven ribosomal protection proteins (RPPs) genes (tetM, tetO, tetQ, tetS, tetT, tetW, tetB/P), and one enzymatic modification gene (tetX). The quantitative real-time PCR was further used to quantify five RPPs genes (tetM, tetO, tetQ, tetW, tetT) and 16S rRNA gene abundances. The concentrations of total tetracyclines (5 typical tetracyclines and 10 of their degradation products) in these soils were measured using liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) and were found to range from 5.4 to 377.8 μgkg-1 dry soil. Bivariate correlation analysis confirmed that absolute tet gene copies (sum of tetM, tetO, tetQ, tetW genes) were strongly correlated with the concentrations of tetracycline residues (r2 = 0.45, P < 0.05), ambient bacterial 16S-rRNA gene copies in each soil sample (r2 = 0.65, P < 0.01), and organic matter in soil (r2 = 0.46, P < 0.05), respectively. Finally, the phylogenetic analysis on tetM combined with culture-independent molecular techniques revealed at least five genotypes of tetM in nine soil samples. © 2010 American Chemical Society.


Zhu G.,CAS Research Center for Eco Environmental Sciences | Wang S.,CAS Research Center for Eco Environmental Sciences | Wang Y.,CAS Research Center for Eco Environmental Sciences | Wang C.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
ISME Journal | Year: 2011

Evidence for anaerobic ammonium oxidation in a paddy field was obtained in Southern China using an isotope-pairing technique, quantitative PCR assays and 16S rRNA gene clone libraries, along with nutrient profiles of soil cores. A paddy field with a high load of slurry manure as fertilizer was selected for this study and was shown to contain a high amount of ammonium (6.2-178.8 mg kg 1). The anaerobic oxidation of ammonium (anammox) rates in this paddy soil ranged between 0.5 and 2.9 nmolN per gram of soil per hour in different depths of the soil core, and the specific cellular anammox activity observed in batch tests ranged from 2.9 to 21 fmol per cell per day. Anammox contributed 4-37% to soil N2 production, the remainder being due to denitrification. The 16S rRNA gene sequences of surface soil were closely related to the anammox bacteria Kuenenia, Anammoxoglobus and Jettenia. Most of the anammox 16S rRNA genes retrieved from the deeper soil were affiliated to Brocadia. The retrieval of mainly bacterial amoA sequences in the upper part of the paddy soil indicated that nitrifying bacteria may be the major source of nitrite for anammox bacteria in the cultivated horizon. In the deeper oxygen-limited parts, only archaeal amoA sequences were found, indicating that archaea may produce nitrite in this part of the soil. It is estimated that a total loss of 76 g N m 2 per year is linked to anammox in the paddy field.


Deng L.,Shaanxi Normal University | Hao Z.,CAS Research Center for Eco Environmental Sciences | Wang J.,Shaanxi Normal University | Zhu G.,Shaanxi Normal University | And 4 more authors.
Electrochimica Acta | Year: 2013

Graphene/multiwall carbon nanotubes/MnO2 (GR/MCNTs/MnO 2) hybrid material with a specific capacitance of 126 F g -1 within a potential window of 0-1.1 V vs. saturated calomel electrode has been synthesized by a simple redox reaction between graphene/multiwall carbon nanotubes (GR/MCNTs) and KMnO4 at room temperature. The morphology and structure of the obtained material are examined by XRD, SEM and TEM. The electrochemical properties are characterized by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The mass percentage of MnO2 with layered structure is 37% in the hybrid material. An asymmetrical electrochemical capacitor (EC) is assembled using GR/MCNT/MnO2 hybrid material as positive electrode and GR/MCNT material as negative electrode, respectively. The electrochemical properties of the two electrodes and the asymmetrical EC are investigated in 1 mol L-1 Na2SO4 aqueous electrolyte. The asymmetrical EC can cycle reversibly in a cell potential of 0-2.0 V and gives a high energy density of 28.33 Wh kg-1, which is much higher than those of symmetrical ECs based on GR/MCNT/MnO2 (6.20 Wh kg-1) and GR/MCNT (3.92 Wh kg-1). Moreover, the asymmetrical EC presents a high power density (5 kW kg-1 at 13.33 Wh kg-1) and excellent cycling performance of 83% retention after 2500 cycles. © 2012 Elsevier Ltd. All Rights Reserved.


Zhang M.,Shaanxi Normal University | Guo S.,Shaanxi Normal University | Zheng L.,Shaanxi Normal University | Zhang G.,Shaanxi Normal University | And 3 more authors.
Electrochimica Acta | Year: 2013

Spinel nickel manganese oxide with large specific surface area and suitable pore size has been prepared from an epoxide-driven sol-gel process and followed by calcining treatment. The structural evolution of the samples obtained at different stages has been characterized by XRD, TEM, XPS, IR and N2 adsorption-desorption. The nickel manganese oxide aerogel is firstly obtained and propylene oxide plays an important role in its formation. The nickel manganese oxide aerogel is calcined at 300 °C for 5 h, it transforms into spinel nickel manganese oxide (NiMn2O4 (300)) with a mesoporous structure, and the specific surface area is 201 m2 g -1 and the pore size is around 8-10 nm. The electrochemical properties are characterized by cyclic voltammetry in 1 mol L-1 Na2SO4 electrolyte. The prepared NiMn2O 4 (300) material not only exhibits an ideal capacitive behavior, but also shows good cycling stability in a neutral electrolyte system. The value of specific capacitance reaches as high as 243 F g-1 at a low scan rate (5 mV s-1), and a specific capacitance of 169 F g-1 is obtained and the initial capacitance value of 96% can be maintained after 5000 cycles of the operation at the scan rate of 20 mV s-1. © 2012 Elsevier Ltd.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Yue L.,CAS Research Center for Eco Environmental Sciences | Liu Z.-T.,Shaanxi Normal University | Liu Z.-H.,Shaanxi Normal University | Hao Z.,CAS Research Center for Eco Environmental Sciences
Journal of Materials Chemistry | Year: 2012

Capacitive deionization (CDI) is a promising desalination technology which has attracted enormous interest in recent years due to its economic advantages over traditional technologies. In this paper, the facilely synthesized graphene and resol (RGO-RF) nanocomposite was proposed as a CDI electrode for the removal of ferric ions. The addition of resol led to less aggregation of the graphite oxide, while after calcination the structure collapsed and the pore size distribution widened. This was confirmed by Brunauer-Emmett-Teller (BET) techniques. The electrode's performances, involving the adsorption isotherm and kinetics, were investigated through batch mode experiment. It was found that the electrosorptive capacity of the RGO-RF electrode was 3.47 mg g -1 with an electrical voltage of 2.0 V and initial solution concentration of 40 mg L -1. This is higher than the corresponding activated carbon and graphene electrode due to the presence of resol which is beneficial in restricting the aggregation of graphene, resulting in a high specific surface area and therefore a high electrosorption capacity. Further, the electrosorption of ferric ions onto RGO-RF follows the Langmuir isotherm, implying monolayer adsorption. Meanwhile, regardless of the electrical voltage, the kinetic analysis illustrated that the pseudo-first-order model can describe the electrosorption behaviour of the RGO-RF electrode very well. © 2012 The Royal Society of Chemistry.


Li Y.,Nanyang Technological University | Zhu G.,CAS Research Center for Eco Environmental Sciences | Ng W.J.,Nanyang Technological University | Ng W.J.,Nanyang Environment and Water Research Institute | Tan S.K.,Nanyang Technological University
Science of the Total Environment | Year: 2014

This paper presents a comprehensive review of the current state of research activities on the application of constructed wetlands for removing pharmaceutical contaminants from wastewater. The focus of the review was placed on the application of constructed wetlands as an alternative secondary wastewater treatment system or as a wastewater polishing treatment system. The design parameters of the reported constructed wetlands including the physical configuration, hydraulic mode, vegetation species, and targeting pharmaceuticals were summarized. The removal efficiencies of pharmaceuticals under different conditions in the wetlands were evaluated at the macroscopic level. In addition, the importance of the three main components of constructed wetlands (substrate, plants and microbes) for pharmaceutical removal was analyzed to elucidate the possible removal mechanisms involved. There is a general consensus among many researchers that constructed wetlands hold great potential of being used as an alternative secondary wastewater treatment system or as a wastewater polishing treatment system for the removal of pharmaceuticals, but relevant reported studies are scarce and are not conclusive in their findings. Current knowledge is limited on the removal efficiencies of pharmaceuticals in constructed wetlands, the removal mechanisms involved, the toxicity to constructed wetlands caused by pharmaceuticals, and the influences of certain important parameters (configuration design, hydraulic mode, temperature and seasonality, pH, oxygen and redox potential, etc.). This review promotes further research on these issues to provide more and better convincing evidences for the function and performance of larger laboratory-scale, pilot-scale or full-scale constructed wetlands. © 2013 Elsevier B.V.


Wu Z.,Hunan University | Zhang P.,Hunan University | Zhang P.,Beijing Forestry University | Zeng G.,Hunan University | And 2 more authors.
Journal of Environmental Engineering (United States) | Year: 2012

Humic acid (HA) removal from water with inorganic polyaluminum coagulants is reported in this paper. Polyaluminum chloride (PAC) and three kinds of polyaluminum chloride sulfate (PACS) with a [SO42-]/[Al3+] (S) molar ratio of 0.02, 0.06, and 0.10 were prepared. The coagulation behaviors of these coagulants were investigated in the view of coagulant dosage, initial pH, and aging time. PACS (S=0.06) showed the best HA removal efficiency, and there was no restabilization within a broad effective dosage range. The proper initial pH range was broad and was 4.0-9.0 for PACS (S=0.06). The stability of PACS (S=0.06) reduced with a long aging time, so the proper aging time should not exceed 1 month. The aluminum species distribution, particle mean size, charge neutralization, and infrared spectrum of prepared coagulants were tested. Results showed that SO42-addition promoted the hydrolysis/polymerization of aluminum and reduced the charge neutralization capacity of PACS. Besides charge neutralization, the bridge-aggregation and sweep-flocculation mechanisms may play important roles for HA removal. The coexisting Ca2+ and kaolin slightly promoted the HA removal with polyaluminum coagulants. © 2012 American Society of Civil Engineers.


Li H.,China Agricultural University | Xiang D.,CAS Research Center for Eco Environmental Sciences | Wang C.,China Agricultural University | Li X.,China Agricultural University | Lou Y.,China Agricultural University
Biology and Fertility of Soils | Year: 2012

A pot experiment was conducted to investigate the effect of epigeic earthworm (Eisenia fetida) and arbuscular mycorrhizal (AM) fungi (Glomus intraradices) on soil enzyme activities and nutrient uptake by maize, which was grown on a mixture of sterilized soil and sand. Maize plants were grown in pots inoculated or not inoculated with AMF, treated or not treated with earthworms. Wheat straw was added as a feed source for earthworms. Mycorrhizal colonization of maize was markedly increased in AM fungi inoculated pots and further increased by addition of epigeic earthworms. AM fungi and epigeic earthworms increased maize shoot and root biomass, respectively. Soil acid phosphatase activity was increased by both earthworms and mycorrhiza, while urease and cellulase activities were only affected by earthworms. Inoculation with AM fungi significantly (p < 0. 001) increased the activity of soil acid phosphatase but decreased soil available phosphorus (P) and potassium (K) concentrations at harvest. Addition of earthworms alone significantly (p < 0. 05) increased soil ammonium-N content, but decreased soil available P and K contents. AM fungi increased maize shoot weight and root P content, while earthworms improved N, P, and K contents in shoots. AM fungi and earthworm interactively increased maize shoot and root biomass through their regulation of soil enzyme activities and on the content of available soil N, P, and K. © 2012 Springer-Verlag.


Xiao P.,CAS Research Center for Eco Environmental Sciences | Xiao F.,CAS Research Center for Eco Environmental Sciences | Wang D.-S.,CAS Research Center for Eco Environmental Sciences | Qin T.,Water Supply Plant Works of Nantong | He S.-P.,Water Supply Plant Works of Nantong
Separation and Purification Technology | Year: 2012

In the present work, a ultrafiltration (UF) low pressure membrane (LPM) made of polyvinyl chloride (PVC) was used with an inline poly-ferric sulfate coagulation in a full scale drinking water treatment plant. The organic foulants and their accumulation behavior in the membrane filtration were investigated during a whole year operation. The evolutions of the surface morphology of the membranes were characterized by scanning electronic microscopy (SEM) and atomic force microscopy (AFM). The results revealed that the cake layer and pore blocked were responsible for the flux declining. Moreover, the roughness of the surface of the membranes continuously increased with the filtration. In order to identify the constitutes of organic foulants, attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), high pressure size exclusion chromatography (HPSEC) and fluorescence excitation-emission matrix (EEM) spectrometry were used to examine the desorbed organic matters from the fouled membranes. The results showed that humic substances kept a very stable situation, indicating that it would not be important in the formation of the combined organic fouling layer. Protein/protein-like substances and soluble microbial product-like (SMP-like) substances were the dominant components in the organic fouling layer in a long-term ultrafiltration of surface water used as a drinking water source. A decrease of protein/protein-like substances and an increase of SMP-like substances with the filtration time were found, which could be attributed to the transition from proteins to SMP in the fouling layer. Thus, the increase of SMP-like substances in the fouling layer would play a significant role on the accumulation of irreversible fouling. © 2012 Elsevier B.V. All rights reserved.


Bai Y.,CAS Research Center for Eco Environmental Sciences | Zhuang C.,Nanjing Institute of Environmental Sciences | Ouyang Z.,CAS Research Center for Eco Environmental Sciences | Zheng H.,CAS Research Center for Eco Environmental Sciences | Jiang B.,CAS Research Center for Eco Environmental Sciences
Ecological Complexity | Year: 2011

Biodiversity and ecosystem services are intrinsically linked. Since human activities have both intensive and extensive impacts on the environment, it is critical to understand spatial relationships between conservation priorities for biodiversity and ecosystem services. The manner in which various aspects of biodiversity relate to ecosystem services and the spatial congruence between biodiversity and these services, is, however, unclear. In the present study in the Baiyangdian watershed, China, we investigated spatial characteristics of biodiversity and ecosystem services using correlation, overlap, and principal component, analyses. The spatial correlations between biodiversity and ecosystem services were found to be high. Biodiversity was positively correlated with soil retention, water yield and carbon sequestration and negatively correlated with N/P retention and pollination. Pairwise overlap was found to be the highest between N and P retention, biodiversity and carbon sequestration, and biodiversity and water yield. Other couples indicated moderate or small overlap. Principal component analysis indicated that biodiversity and six ecosystem services could be divided into two groups, which could be managed and conserved separately. It can be concluded that biodiversity priorities co-occur with water yield, soil retention and carbon sequestration, and do not co-occur with N/P retention and pollination. Conservation of a biodiversity hotspot was associated with maintaining 45.02% of a carbon sequestration hotspot, 42.05% of a water yield hotspot, and 23.29% of a soil retention hotspot, indicating that conserving biodiversity will also result in the protection of these services. The bundling of biodiversity and ecosystem services is thus both possible and practical. Our findings provide valuable information on congruence and divergence among conservation hotspots and the protection of ecosystem services. They also indicate that a systematic and comprehensive approach that can have wide-ranging policy implications in terms of optimizing conservation strategies for multiple ecosystem services. © 2011 Elsevier B.V.


Li H.,Qingdao Agricultural University | Li H.,China Agricultural University | Wang C.,China Agricultural University | Li X.,China Agricultural University | Xiang D.,CAS Research Center for Eco Environmental Sciences
Biology and Fertility of Soils | Year: 2013

Earthworms and arbuscular mycorrhizal fungi (AMF) are important macrofauna and microorganisms of the rhizosphere. The effect of the inoculation of soil with earthworms (Aporrectodea trapezoides) and mycorrhiza (Rhizophagus intraradices) on the community structure of mycorrhizal fungi and plant nutrient uptake was determined with split plots in a maize field. Maize plants were inoculated or not inoculated with AMF, each treated with or without earthworms. Wheat straw was added as a feed source for earthworms. Inoculating AMF significantly increased maize yield (p < 0.05), and the yield was further enhanced by the addition of earthworms. Alkaline phosphomonoesterase activities, soil microbial biomass carbon (SMBC) and nitrogen (SMBN) increased with the addition of both earthworms and AMF. Soil inorganic N and available K were positively affected by earthworms, while available P showed a negative relationship with AMF. Treatment with both AMF and earthworms increased shoot and root biomass as well as their N and P uptake by affecting soil phosphomonoesterase and urease activities, SMBC, SMBN, and the content of available nutrients in soil. The applied fungal inoculants were successfully traced by polymerase chain reaction with novel primers (AML1 and AML2) which target the small subunit rRNA gene. The amplicons were classified by restriction fragment length polymorphism and sequencing. Moreover, field inoculation with inocula of non-native isolates of R. intraradices appeared to have stimulated root colonization and yield of maize. Adding earthworms might influence native AMF community, and the corresponding abundance increased after earthworms were inoculated, which has positive effects on maize growth. © 2013 Springer-Verlag Berlin Heidelberg.


Wang S.,CAS Research Center for Eco Environmental Sciences | Wang S.,University of Science and Technology Beijing | Wang Y.,CAS Research Center for Eco Environmental Sciences | Feng X.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2011

With the rapid development of ammonia-synthesizing industry, the ammonia-nitrogen pollution in wetlands acting as the sink of point and diffuse pollution has been increased dramatically. Most of ammonia-nitrogen is oxidized at least once by ammonia-oxidizing prokaryotes to complete the nitrogen cycle. Current research findings have expanded the known ammonia-oxidizing prokaryotes from the domain Bacteria to Archaea. However, in the complex wetlands environment, it remains unclear whether ammonia oxidation is exclusively or predominantly linked to Archaea or Bacteria as implied by specific high abundance. In this research, the abundance and composition of Archaea and Bacteria in sediments of four kinds of wetlands with different nitrogen concentration were investigated by using quantitative real-time polymerase chain reaction, cloning, and sequencing approaches based on amoA genes. The results indicated that AOA distributed widely in wetland sediments, and the phylogenetic tree revealed that archaeal amoA functional gene sequences from wetlands sediments cluster as two major evolutionary branches: soil/sediment and sediment/water. The bacteria functionally dominated microbial ammonia oxidation in different wetlands sediments on the basis of molecule analysis, potential nitrification rate, and soil chemistry. Moreover, the factors influencing AOA and AOB abundances with environmental indicator were also analyzed, and the results addressed the copy numbers of archaeal and bacterial amoA functional gene having the higher correlation with pH and ammonia concentration. The pH had relatively great negative impact on the abundance of AOA and AOB, while ammonia concentration showed positive impact on AOB abundance only. These findings could be fundamental to improve understanding of the importance of AOB and AOA in nitrogen and other nutrients cycle in wetland ecosystems. © 2011 Springer-Verlag.


Han Y.,Beijing Forestry University | Fan Y.,Chinese Academy of Agricultural Sciences | Yang P.,China Agricultural University | Wang X.,CAS Research Center for Eco Environmental Sciences | And 4 more authors.
Geoderma | Year: 2014

This study provides a new understanding to sources of nitrogen (N), and may serve as a foundation for further exploration of anthropogenic effects on N inputs. Estimation of net anthropogenic nitrogen inputs (NANI) was based on an inventory of atmospheric N deposition, N fertilizer use, N in human food and animal feed, seeding N and N fixation. This study took a step forward to calculate NANI in detail on a regional scale, and analyzed its temporal variations and geographic differences. Over the past 28years, NANI increased significantly in Mainland China, from 2360kgNkm-2yr-1 to 5013kgNkm-2yr-1. On a geographical basis, NANI was higher in southeast where China's eight major watersheds are located than in northwest, and the largest NANI, 26160kgNkm-2yr-1, appeared in Shanghai. The administrative regions corresponding to Haihe watershed, Huaihe watershed and Tai lake watershed have the largest NANI. N input of fertilizer is the largest source of NANI, followed by atmospheric N deposition and N fixation. The primary factor in relation to the change in NANI is total population density, followed by cultivated land area and total grain yield. In those densely populated large cities and watersheds, reasonably allocating the social resources to reduce the existing population density is the most effective way to address the problem of high N inputs, while in those agriculture-dominated regions and watersheds, the most effective way for reducing NANI is to improve fertilizer utilization efficiency in agriculture. © 2013 Elsevier B.V.


Oda Y.,CAS Research Center for Eco Environmental Sciences | Zhang Y.,CAS Research Center for Eco Environmental Sciences | Buchinger S.,Federal Institute of Hydrology BfG | Reifferscheid G.,Federal Institute of Hydrology BfG | Yang M.,CAS Research Center for Eco Environmental Sciences
Environmental and Molecular Mutagenesis | Year: 2012

Human sulfotransferase (SULT) 1A1, 1A2, and 1A3 cDNA genes were subcloned separately into the pTrc99A KM vector. The generated plasmids were introduced into the Salmonella typhimurium O-acetyltransferase-deficient strain NM6000 (TA1538/1,8-DNP/pSK1002), resulting in the new strains NM7001, NM7002, and NM7003. We compared the sensitivities of these three strains with the parental strain NM7000 against 51 chemicals including aromatic amines, nitroarenes, alkenylbenzenes, estrogens-like chemicals, and other compounds with and without S9 mix by making use of the umu test system that is based on the bacterial SOS induction. 2-Amino-6-methyl-dipyrido[1,2-α:3′,2′-d]imidazole, 3-methoxy-4-aminoazobenzene, 3-nitrobenzanthrone, 5-nitroacenaphthene, and 3,9-dinitrofluoranthene caused high genotoxicity in the NM7001 strain. The genotoxic effects of 2-aminofluorene, 2-acetylaminofluorene, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-nitrofluorene, 1-nitropyrene, and 2-nitropropane were stronger in the NM7002 strain compared with the NM7001 and NM7003 strains. Among the tested benzylic and allylic compounds, 1-hydroxymethylpyrene was detected in the NM7001 strain with the highest sensitivity. Estragole and 1′-hydroxysafrole exhibited strong genotoxicity in the NM7003 strain. The estrogen-like chemicals such as bisphenol A, genistein, p,n-nonylphenol, and 4-hydroxytamoxifen were not detected as genotoxins in any strain used. Collectively, the present results suggest that the generated test strains are valuable tools in order to elucidate the role of SULT enzymes in the bioactivation of chemicals to environmental carcinogens. © 2011 Wiley Periodicals, Inc.


Zhu G.,CAS Research Center for Eco Environmental Sciences | Wang S.,CAS Research Center for Eco Environmental Sciences | Wang S.,Harbin Institute of Technology | Wang W.,CAS Research Center for Eco Environmental Sciences | And 10 more authors.
Nature Geoscience | Year: 2013

For decades, the conversion of organic nitrogen to dinitrogen gas by heterotrophic bacteria, termed heterotrophic denitrification, was assumed to be the main pathway of nitrogen loss in natural ecosystems. Recently, however, autotrophic bacteria have been shown to oxidize ammonium in the absence of oxygen, yielding dinitrogen gas. This process, termed anammox, accounts for over 50% of nitrogen loss in marine ecosystems. However, the significance of anammox in freshwater ecosystems has remained uncertain. Here, we report the occurrence of anammox hotspots at land-freshwater interfaces of lake riparian zones in North China, using molecular and isotopic tracing technologies. Laboratory incubations measuring anammox activity at substrate concentrations no more than 10% of those observed in situ yielded some of the highest potential activities reported for natural environments to date. Potential rates of anammox peaked in sediments sampled from the interface between land and water, as did the abundance of annamox bacteria. Scaling our findings up to the entire lake system, we estimate that interfacial anammox hotspots account for the loss of 103 g Nm-2 yr-1 from this lake region, and around one fifth of the nitrogen lost from the land-water interface. © 2013 Macmillan Publishers Limited. All rights reserved.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Li Y.,CAS Research Center for Eco Environmental Sciences | Liu Z.,Shaanxi Normal University | Hao Z.,CAS Research Center for Eco Environmental Sciences
Journal of Materials Chemistry A | Year: 2013

Reduced graphite oxide-NiFe2O4 (RGO-NiFe 2O4) composites were synthesized by adding different amounts of NH3·H2O into a mixed aqueous solution of graphite oxide, Ni(NO3)2 and Fe(NO3) 3 at room temperature. NH3·H2O was used to adjust the synthesis system's pH value. The morphology and the microstructure of the as-prepared composites were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscope (TEM) techniques. The structure characterizations indicate that NiFe2O 4 successfully deposited on the surface of the RGO and the morphologies of RGO-NiFe2O4 show a transparent structure with NiFe2O4 homogeneously distributed on the RGO surfaces. Capacitive properties of the synthesized electrodes were studied using cyclic voltammetry and electrochemical impedance spectroscopy in a three-electrode experimental setup using 1 M Na2SO4 aqueous solution as electrolyte. It is found that the pH value plays an important role in controlling the electrochemical properties of these electrodes. Among the synthesized electrodes, RGO-NiFe10 (pH = 10) shows the best capacitive properties because of its suitable particle size and good dispersion property. It could be anticipated that the synthesized electrodes will gain promising applications as novel electrode materials in supercapacitors and other devices by virtue of their outstanding characteristics of controllable capacitance and facile synthesis. This journal is © The Royal Society of Chemistry 2013.


Feng Z.,CAS Research Center for Eco Environmental Sciences | Hu E.,CAS Research Center for Eco Environmental Sciences | Wang X.,CAS Research Center for Eco Environmental Sciences | Jiang L.,CAS Research Center for Eco Environmental Sciences | Liu X.,China Agricultural University
Environmental Pollution | Year: 2015

Ground-level ozone (O3) pollution has become one of the top environmental issues in China, especially in those economically vibrant and densely populated regions. In this paper, we reviewed studies on the O3 concentration observation and O3 effects on food crops throughout China. Data from 118 O3 monitoring sites reported in the literature show that the variability of O3 concentration is a function of geographic location. The impacts of O3 on food crops (wheat and rice) were studied at five sites, equipped with Open Top Chamber or O3-FACE (free-air O3 concentration enrichment) system. Based on exposure concentration and stomatal O3 flux-response relationships obtained from the O3-FACE experimental results in China, we found that throughout China current and future O3 levels induce wheat yield loss by 6.4-14.9% and 14.8-23.0% respectively. Some policies to reduce ozone pollution and impacts are suggested. © 2015 Elsevier Ltd. All rights reserved.


Deng L.,Shaanxi Normal University | Wang J.,Shaanxi Normal University | Zhu G.,Shaanxi Normal University | Kang L.,Shaanxi Normal University | And 5 more authors.
Journal of Power Sources | Year: 2014

Ruthenium oxide/graphene (RuO2/GR) hybrid materials for high performance electrochemical capacitor have been prepared by a solution-phase assembly technology between RuO2 nanosheets and GR nanosheets at room temperature. The high dispersion of RuO2 and GR nanosheets maintains a high structural stability for the hybrid material, and causes an obvious synergistic effect between the RuO2 and GR nanosheets. A specific capacitance of 479 F g-1 has been obtained for the hybrid material with RuO2 mass content of 40% (abbreviated as RuGR46), and a high specific capacitance of 998 F g-1 obtained for RuO2 in the electrode. The utilization of RuO2 in the RuGR46 hybrid material increases by adding GR, and the capacitance of RuGR46 is quite comparable to that of the pristine RuO2·xH2O while 60 wt% of RuO2 can be saved. A symmetrical electrochemical capacitor based on the RuGR46 electrode is assembled with 0.5 mol L-1 H 2SO4 solution as the electrolyte in a voltage of 0-1.2 V. It can give a high energy density of 20.28 Wh kg-1 at a power density of 600 W kg-1. Moreover, it presents a high power density (14.03 Wh kg-1 at 12 kW kg-1) and excellent cycle performance. © 2013 Elsevier B.V. All rights reserved.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Zhang X.,CAS Research Center for Eco Environmental Sciences | Wang J.,CAS Research Center for Eco Environmental Sciences | Zou L.,University of South Australia | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2013

Graphene/NiAl layered double-hydroxide (LDH) composite with high capacitive properties has been prepared in a friendly one-step process. It is found that NiAl-LDH is formed in the addition of precipitator agent (NaOH and NaNO3) by hydrothermal method, at the same time graphene oxide (GO) is reduced to graphene. The morphology and structure of the obtained material are examined by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), transmission electron microscope (TEM), and scanning electron microscope (SEM) techniques. It is revealed that the NiAl-LDH disperses well on the surface of graphene and the formation of NiAl-LDH nanoparticles is beneficial to the peeling of graphene (RGO). More importantly, the addition of NiAl-LDH to graphene endows the materials with desirable specific surface areas and higher porosity. These structural advantages result in higher specific capacitance compared with pristine graphene. Electrochemical property investigations show that the graphene/NiAl-LDH had a higher specific capacitance than graphene. © 2013.


Song M.,CAS Research Center for Eco Environmental Sciences | Zeng L.,CAS Research Center for Eco Environmental Sciences | Yuan S.,Peking Union Medical College | Yin J.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemosphere | Year: 2013

Functionalization is an important technique to increase the solubility and biocompatibility of single-wall carbon nanotubes (SWCNTs). In this study, we investigated the cytotoxicity of four types of SWCNTs functionalized with hydroxyl, amino, carboxyl and polyethyleneglycol on MCF7 cells. These functionalized SWCNTs (f-SWCNTs) have insignificant effects on mitochondrial activity and ROS production in MCF7 cells at all test concentrations. However, explicit results revealed that all the tested f-SWCNTs could cause changes of cell morphology, induce cell membrane damage, decrease cell adhesion, and increase cell apoptosis. Therefore, this study shows the potential side effects of f-SWCNTs accompanying with the increase of dispersibility and stability in environment or serum (to prevent their aggregation), and highlights the need for further research to examine the potential toxicity of f-SWCNTs before they are used in the environmental and biomedical fields. © 2013 Elsevier Ltd.


Lu A.,CAS Research Center for Eco Environmental Sciences | Lu A.,Center for Monitoring Research | Wang J.,Center for Monitoring Research | Qin X.,Chinese National Engineering Research Center for Information Technology in Agriculture | And 3 more authors.
Science of the Total Environment | Year: 2012

An extensive survey was conducted in this study to determine the spatial distribution and possible sources of heavy metals in the agricultural soils in Shunyi, a representative agricultural suburb in Beijing, China. A total of 412 surface soil samples were collected at a density of one sample per km2, and concentrations of As, Cd, Cu, Hg, Pb and Zn were analyzed. The mean values of the heavy metals were 7.85±2.13, 0.136±0.061, 22.4±6.31, 0.073±0.049, 20.4±5.2, and 69.8±16.5mgkg-1 for As, Cd, Cu, Hg, Pb, and Zn, respectively, slightly higher than their background values of Beijing topsoil with the exception of Pb, but lower than the guideline values of Chinese Environmental Quality Standard for Soils. Multivariate and geostatistical analyses suggested that soil contamination of Cd, Cu and Zn was mainly derived from agricultural practices. Whereas, As and Pb were due mainly to soil parent materials, and Hg was caused by the atmospheric deposits from Beijing City. The identification of heavy metal sources in agricultural soils is a basis for undertaking appropriate action to protect soil quality. © 2012 Elsevier B.V.


Xue W.J.,CAS Research Center for Eco Environmental Sciences | Wang Y.F.,CAS Research Center for Eco Environmental Sciences | Li P.,CAS Research Center for Eco Environmental Sciences | Liu Z.-T.,Shaanxi Normal University | And 2 more authors.
Catalysis Communications | Year: 2011

Au/Co3O4 catalysts with different morphologies (nanorods, nanopolyhedra and nanocubes) were successfully synthesized and evaluated for ethylene complete oxidation. We found that support morphology has a significant effect on catalytic activity, which is related to the exposed planes of different morphological Co3O4. HRTEM revealed the Co3O4-nanorods predominantly exposes {110} planes, while the dominant exposed planes of Co3O4-nanopolyhedra and -nanocubes are {011} and {001} planes, respectively. Compared with {011} and {001} planes, {110} planes exhibit the maximum amount of oxygen vacancies, which play a major role in ethylene oxidation. Therefore, Au/Co 3O4-nanorods exhibits extraordinary catalytic activity, yielding 93.7% ethylene conversion at 0 °C. © 2011 Elsevier B.V.


Zhang G.,China Agricultural University | Cao Z.-P.,China Agricultural University | Hu C.-J.,CAS Research Center for Eco Environmental Sciences
Chinese Journal of Applied Ecology | Year: 2011

Soil organic carbon is of heterogeneity in components. The active components are sensitive to agricultural management, while the inert components play an important role in carbon fixation. Soil organic carbon fractionation mainly includes physical, chemical, and biological fractionations. Physical fractionation is to separate the organic carbon into active and inert components based on the density, particle size, and its spatial distribution; chemical fractionation is to separate the organic carbon into various components based on the solubility, hydrolizability, and chemical reactivity of organic carbon in a variety of extracting agents. In chemical fractionation, the dissolved organic carbon is bio-available, including organic acids, phenols, and carbohydrates, and the acid- hydrolyzed organic carbon can be divided into active and inert organic carbons. Simulated enzymatic oxidation by using KMnO4 can separate organic carbon into active and non-active carbon. Biological fractionation can differentiate microbial biomass carbon and potential mineralizable carbon. Under different farmland management practices, the chemical composition and pool capacity of soil organic carbon fractions will have different variations, giving different effects on soil quality. To identify the qualitative or quantitative relationships between soil organic carbon components and carbon deposition, we should strengthen the standardization study of various fractionation methods, explore the integrated application of different fractionation methods, and sum up the most appropriate organic carbon fractionation method or the appropriate combined fractionation methods for different farmland management practices.


Shi Y.,CAS Research Center for Eco Environmental Sciences | Lu Y.,CAS Research Center for Eco Environmental Sciences | Meng F.,China Agricultural University | Guo F.,China Agricultural University | Zheng X.,CAS Research Center for Eco Environmental Sciences
Ecotoxicology and Environmental Safety | Year: 2013

The occurrence of ∑HCHs, ∑DDTs, protozoa abundance and their community structure in surface soils of orchards, vegetable lands, and barren lands in northern west outskirts of Beijing were detected in order to investigate the protozoa responses to low dose organic chlorinated Pesticides (OCPs) after long-term field-based exposure. Significant differences in total concentrations of HCHs and DDTs were found among the three general groups ranking in decreasing order of concentration from orchard>vegetable lands >barren lands. Ciliate was the rare group in surface soils of all the sampling groups. The abundance of flagellate, ciliate, and amoebae in vegetable soils were significantly higher than those in orchard soils. The abundance of all the taxa of protozoa was strongly negative correlated with the residue level of ∑HCHs and ∑DDTs (P<0.05) in agricultural soils. However, no negative correlation between the residue levels of OCPs and protozoa abundance was shown in both the orchard and the barren soils. This field study demonstrated a considerable long-term impact of the OCPs residue on the abundance of protozoa in soils, and that the abundance of soil protozoa was much more influenced by land use type in association with different soil properties. © 2013 Elsevier Inc..


Ren W.,Auburn University | Tian H.,Auburn University | Tao B.,Auburn University | Huang Y.,CAS Institute of Botany | And 2 more authors.
Global Change Biology | Year: 2012

Much concern has been raised about how multifactor global change has affected food security and carbon sequestration capacity in China. By using a process-based ecosystem model, the Dynamic Land Ecosystem Model (DLEM), in conjunction with the newly developed driving information on multiple environmental factors (climate, atmospheric CO 2, tropospheric ozone, nitrogen deposition, and land cover/land use change), we quantified spatial and temporal patterns of net primary production (NPP) and soil organic carbon storage (SOC) across China's croplands during 1980-2005 and investigated the underlying mechanisms. Simulated results showed that both crop NPP and SOC increased from 1980 to 2005, and the highest annual NPP occurred in the Southeast (SE) region (0.32 Pg C yr -1, 35.4% of the total NPP) whereas the largest annual SOC (2.29 Pg C yr -1, 35.4% of the total SOC) was found in the Northeast (NE) region. Land management practices, particularly nitrogen fertilizer application, appear to be the most important factor in stimulating increase in NPP and SOC. However, tropospheric ozone pollution and climate change led to NPP reduction and SOC loss. Our results suggest that China's crop productivity and soil carbon storage could be enhanced through minimizing tropospheric ozone pollution and improving nitrogen fertilizer use efficiency. © 2012 Blackwell Publishing Ltd.


Shao J.,CAS Research Center for Eco Environmental Sciences | Huang C.-H.,CAS Research Center for Eco Environmental Sciences | Kalyanaraman B.,Medical College of Wisconsin | Zhu B.-Z.,CAS Research Center for Eco Environmental Sciences | Zhu B.-Z.,Oregon State University
Free Radical Biology and Medicine | Year: 2013

Halogenated quinones are a class of carcinogenic intermediates and are newly identified chlorination disinfection by-products in drinking water. We found recently that the highly reactive and biologically important hydroxyl radical (•OH) can be produced by halogenated quinones and H 2O2 independent of transition metal ions. However, it is not clear whether these quinoid carcinogens and H2O2 can oxidize the nucleoside 5-methyl-2′-deoxycytidine (5mdC) to its methyl oxidation products and, if so, what the underlying molecular mechanism is. Here we show that three methyl oxidation products, 5-(hydroperoxymethyl)-, 5-(hydroxymethyl)-, and 5-formyl-2′-deoxycytidine, could be produced when 5mdC was treated with tetrachloro-1,4-benzoquinone (TCBQ) and H 2O2. The formation of the oxidation products was markedly inhibited by typical •OH scavengers and under anaerobic conditions. Analogous effects were observed with other halogenated quinones and the classic Fenton system. Based on these data, we propose that the oxidation of 5mdC by TCBQ/H2O2 might be through the following mechanism: •OH produced by TCBQ/H2O2 may first abstract hydrogen from the methyl group of 5mdC, leading to the formation of 5-(2′-deoxycytidylyl)methyl radical, which may combine with O 2 to form the peroxyl radical. The unstable peroxyl radical transforms into the corresponding hydroperoxide 5-(hydroperoxymethyl)-2′- deoxycytidine, which reacts with TCBQ and results in the formation of 5-(hydroxymethyl)-2′-deoxycytidine and 5-formyl-2′-deoxycytidine. This is the first report that halogenated quinoid carcinogens and H 2O2 can induce potent methyl oxidation of 5mdC via a metal-independent mechanism, which may partly explain their potential carcinogenicity. © 2013 Elsevier Inc.


Luo L.,Nanjing University of Aeronautics and Astronautics | Shen K.,Nanjing University of Aeronautics and Astronautics | Xu Q.,Nanjing Southeast University | Zhou Q.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Journal of Alloys and Compounds | Year: 2013

Multiferroic Co substituted BiFeO3 (BiFe0.95Co 0.05O3) compound was synthesized by complex sol-gel method and its potential application as an efficient magnetic adsorbent in sorption removal of organic contaminants (like Rhodamine B as a model compound) was investigated. The XRD, Raman, and PPMS measurement revealed that Co substituted BiFeO3 enhances magnetic properties dramatically at room temperature without inducing any impurity phase. This aspect is very useful for many applications of Co substituted BiFeO3 especially in magnetic separation of this catalyst after its utilization in water purification. The adsorption kinetics, isotherm, thermodynamic as well as the possible sorption mechanism was studied through batch experiments. Almost no negative effect on the sorption performance (i.e. the sorption rate and saturated sorption capacity) was found after substitution of Co in BiFeO3. In addition, this substitution give rise to much higher coercive force of BiFe 0.95Co0.05O3 which can be recycled more easily by magnetic separation technology. © 2012 Elsevier B.V. All rights reserved.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Ma C.,CAS Research Center for Eco Environmental Sciences | Wang H.,CAS Research Center for Eco Environmental Sciences | Liu Z.,Shaanxi Normal University | Hao Z.,CAS Research Center for Eco Environmental Sciences
Journal of Alloys and Compounds | Year: 2013

Fe2O3-graphene nanocomposite with high capacitive properties had been prepared friendly and facilely by hydrothermal method in one-step. The morphology and structure of the obtained material were examined by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscope (TEM) techniques. It was revealed by TEM images that Fe 2O3 nanoparticles grow well on the surface of graphene and the formation of Fe2O3 nanoparticles hinders the aggregation of graphene (reduced graphene oxide, namely, RGO). Electrochemical properties of the synthesized materials were characterized by serials of electrochemical measurements in 1 M Na2SO4 electrolyte. Fe2O3-graphene nanocomposite electrode show higher specific capacitance than graphene, indicating an accelerative effect of Fe 2O3 and graphene on improving the electrochemical performance of the electrode. The specific capacitance of Fe2O 3-graphene nanocomposite is 226 F/g at a current density of 1 A/g. These attractive results indicate it is possible to seek and develop the promising, environmentally benign and commercial electrodes material based on Fe2O3 and graphene. Crown Copyright © 2012 Published by Elsevier B.V. All rights reserved.


Qian H.,University of Illinois at Springfield | Chen S.,Nanjing Institute of Environmental Sciences | Chen S.,CAS Research Center for Eco Environmental Sciences | Mao L.,CAS Institute of Botany | And 2 more authors.
Global Ecology and Biogeography | Year: 2013

Aim: Ecologists have generally agreed that β-diversity is driven at least in part by ecological processes and mechanisms of community assembly and is a key determinant of global patterns of species richness. This idea has been challenged by a recent study based on an individual-based null model approach, which aims to account for the species pool. The goal of the present study is twofold: (1) to analyse data sets from different parts of the world to determine whether there are significant latitude-β-diversity gradients after accounting for the species pool, and (2) to evaluate the validity of the null model. Location: Global. Methods: A total of 257 forest plots, each being 0.1 ha in size and having 10 0.01-ha subplots, were used. We conducted four sets of analyses. A modified version of Whittaker's β-diversity index was used to quantify β-diversity for each forest plot. A randomization procedure was used to determine expected β-diversity. Results: The number of individuals per species, which characterizes species abundance distribution, alone explains 56.8-84.2% of the variation in observed β-diversity. Species pool (γ-diversity) explained only an additional 2.6-15.2% of the variation in observed β-diversity. Latitude explains 18.6% of the variation in raw β deviation in Gentry's global data set, and explains 11.0-11.6% of the variation in standardized β deviation in the global and three regional analyses. Latitude explains 33.2-46.2% of the variation in the number of individuals per species. Main conclusions: Species abundance distribution, rather than species pool size, plays a key role in driving latitude-β-diversity gradients for β-diversity in local forest communities. The individual-based null model is not a valid null model for investigating β-diversity gradients driven by mechanisms of local community assembly because the null model incorporates species abundance distributions, which are driven by mechanisms of local community assembly and in turn generate β-diversity gradients. © 2012 John Wiley & Sons Ltd.


Hartono S.B.,University of Queensland | Qiao S.Z.,University of Queensland | Liu J.,University of Queensland | Jack K.,University of Queensland | And 4 more authors.
Journal of Physical Chemistry C | Year: 2010

Organo-functionalized FDU-12 type silicas exhibiting large pore sizes and ordered mesoporous structures were synthesized at low reaction (15 °C) and high hydrothermal (160 °C) temperatures via the co-condensation of tetraethoxysilane (TEOS) with a suite of organosilanes, i.e., 3-aminopropyltriethoxysilane (APTES), 3-mercaptopropyltrimethoxysilane (MPTMS), vinyltrimethoxysilane (VTMS), and phenyltrimethoxysilane (PTMS), in the presence of structure directing micelles formed using the surfactant pluronic F127 and the pore enlarging reagent trimethylbenzene (TMB). Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) confirmed that all synthesized materials possessed a face-centered cubic mesostructure (space group Fm3̄ m), while nitrogen sorption analyses showed that the synthesized materials had extra large pores with cavity sizes of up to 25.4 nm and entrance sizes of up to 10.8 nm. X-ray photoelectron spectroscopy (XPS) and 13C solid-state magic-angle spinning nuclear magnetic resonance (13C-MAS NMR) measurements verified the incorporation of the different organosilanes into the silica network and more importantly on the inner and outer surfaces of the materials. As-obtained mesoporous silicas were tested in protein immobilization studies using bovine serum albumin and the cellulose-hydrolyzing enzyme cellulase, which in itself is a mixture of three large enzymes. Enzyme immobilization efficiency, activity, and stability varied significantly with organic functionality due to size exclusion effects at pore entries, electrostatic and hydrophobic interactions between the organo-functionalized surfaces and the enzymes, and conformational changes of the enzymes which can occur on some of the material surfaces. As a result, phenyl (PTMS)- and thiol (MPTMS)-functionalized FDU-12 mesoporous silicas had a very low adsorption capacity of proteins because of their small pore sizes. Amino (APTES)-functionalized FDU-12 mesoporous silica showed the highest adsorption amount of proteins yet the lowest activity of immobilized cellulase. Cellulase immobilization on vinyl (VTMS)-functionalized FDU-12 mesoporous silica appeared to be the most promising approach, since it occurred with high efficiency, maintained enzyme activity, and provided temporal enzyme stability. © 2010 American Chemical Society.


Roonasi P.,Lulea University of Technology | Yang X.,Lulea University of Technology | Yang X.,CAS Research Center for Eco Environmental Sciences | Holmgren A.,Lulea University of Technology
Journal of Colloid and Interface Science | Year: 2010

Attenuated Total Reflection (ATR) IR spectroscopy was utilized to monitor adsorption of sodium oleate and sodium silicate onto synthetic magnetite at pH = 8.5, both individually and in a competitive manner. Oleate was adsorbed within a concentration range of 0.01-0.5 mM. It was observed that adsorption of oleate increased linearly with increasing concentration of oleate in solution up to a concentration of 0.1 mM. The infrared spectrum of oleate showed a broad single band at 1535 cm-1 assigned to the asymmetric stretching vibration of carboxylate, implying chemisorption of oleate to the magnetite surface. The kinetics of oleate adsorption followed a pseudo first-order reaction with an apparent rate constant of k1 = 0.030 ± 0.002 min-1. Competitve adsorption of silicate and oleate was performed either by adding silicate solution to a magnetite film initially equilibrated with 0.1 mM oleate or adding oleate solution to magnetite treated with silicate solutions in the concentration range 0.1-5 mM. It was shown that silicate, within reasonable time, had only minor effect on the amount of oleate already adsorbed on magnetite. On the other hand, oleate did not efficiently compete with silicate if the latter substance was already adsorbed on the iron oxide. © 2009 Elsevier Inc. All rights reserved.


Chen L.,CAS Institute of Botany | Li P.,CAS Research Center for Eco Environmental Sciences | Yang Y.,CAS Institute of Botany
Journal of Geophysical Research G: Biogeosciences | Year: 2016

Knowledge of nitrogen (N) and phosphorus (P) stoichiometry is essential for understanding biogeochemical cycle and ecosystem functioning. However, large-scale patterns in soil stoichiometry are not yet fully understood along environmental gradients nor over the temporal scale. Using a comprehensive data set and artificial neural network approach, we evaluated spatial and temporal patterns in topsoil N and P concentrations and N:P ratio across China's forests. Our results revealed that soil weathering stage, climatic factors (i.e., temperature and precipitation), and forest types jointly explained approximately 34.1% and 30.4% of spatial variations in soil N and P, respectively. By contrast, only precipitation could explain the variation in N:P ratio, with soil N:P ratio exhibiting a trend of increase along the precipitation gradient. The observed spatial patterns in soil N:P ratio were consistent with previous findings derived from plants and microbes, suggesting that variation in precipitation may induce the imbalance of N:P stoichiometry in forest ecosystems. Our results also indicated that topsoil N:P ratios exhibited a significant increase from the 1980s to 2000s. However, the associations of N:P dynamics with a single element largely depended on forest type. In evergreen forests, soil N:P dynamics were caused by increasing N and decreasing P. Conversely, N:P changes in deciduous broadleaf forests were triggered only by soil N accumulation. Overall, these results demonstrated a stoichiometric shift in soil N:P both spatially and temporally, implying that nutrient imbalance between soil N and P may be accelerated under global change scenarios. ©2016. American Geophysical Union. All Rights Reserved.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Dou B.,CAS Research Center for Eco Environmental Sciences | Zheng L.,Shaanxi Normal University | Zhang G.,Shaanxi Normal University | And 2 more authors.
Desalination | Year: 2012

In this work, functional graphene nanocomposite (reduced graphite oxidate-resol like material, named RGO-RF) was successfully synthesized and used as electrode in capacitive deionization (CDI) process. The porosity, morphology and electrochemical characteristics of RGO-RF were confirmed by N 2 adsorption-desorption curve, transmission electron microscopy and cyclic voltammetry, respectively. Further, the deionization performances of the RGO-RF electrode, reduced graphite oxidate (RGO) and activated carbon (AC) were examined for comparison by a lab-scale CDI experimental system. It is found that the RGO-RF shows the best deionization performance among the three target materials, indicating that it is a novel electrode material which has a great potential as effective electrode for CDI. Besides, the electrosorption isotherms and electrosorption kinetics were studied, and it is found that the ion sorption behaviour of RGO-RF follows a Langmuir adsorption isotherm, implying monolayer adsorption. © 2012 Elsevier B.V.


Hao Q.-Q.,Shaanxi Normal University | Liu Z.-W.,Shaanxi Normal University | Zhang B.,Fritz Haber Institute of the Max Planck Society | Wang G.-W.,Shaanxi Normal University | And 6 more authors.
Chemistry of Materials | Year: 2012

A single template of alkyl ammonium is sufficient to assemble porous clay heterostructures intercalated with metal oxide (PCH), and its mild acidity and small mesopores make Co/PCH a good catalyst for controlling the product distribution of Fischer-Tropsch synthesis with a very high selectivity of liquid hydrocarbons. © 2012 American Chemical Society.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Liu S.,CAS Research Center for Eco Environmental Sciences | Ma J.,CAS Research Center for Eco Environmental Sciences | Qu G.,CAS Research Center for Eco Environmental Sciences | And 6 more authors.
ACS Nano | Year: 2013

Due to its antimicrobial activity, nanosilver (nAg) has become the most widely used nanomaterial. Thus far, the mechanisms responsible for nAg-induced antimicrobial properties and nAg-mediated toxicity to organisms have not been clearly recognized. Silver (Ag) ions certainly play a crucial role, and the form of nanoparticles can change the dissolution rate, bioavailability, biodistribution, and cellular uptake of Ag. However, whether nAg exerts direct "particle-specific" effects has been under debate. Here we demonstrated that nAg exhibited a robust inhibition on RNA polymerase activity and overall RNA transcription through direct Ag binding to RNA polymerase, which is separated from the cytotoxicity pathway induced by Ag ions. nAg treatment in vitro resulted in reduced hemoglobin concentration in erythroid cells; in vivo administration of nAg in mice caused profound reduction of hemoglobin content in embryonic erythrocytes, associated with anemia in the embryos. Embryonic anemia and general proliferation deficit due to the significant inhibition on RNA synthesis, at least partially, accounted for embryonic developmental retardation upon nAg administration. To date, there is no conclusive answer to the sources of nAg-mediated toxicity: Ag ions or "particle-specific" effects, or both. We here demonstrated that both Ag ions and nAg particles simultaneously existed inside cells, demonstrating the "Trojan horse" effects of nAg particles in posing biological impacts on erythroid cells. Moreover, our results suggested that "particle-specific" effects could be the predominant mediator in eliciting biological influences on erythroid cells under relatively low concentrations of nAg exposure. The combined data highlighted the inhibitory effect of nAg on RNA polymerase activity through a direct reciprocal interaction. © 2013 American Chemical Society.


Wang Y.,CAS Research Center for Eco Environmental Sciences | Wang Y.,Tsinghua University | Holler S.,Wuppertal Institute for Climate | Viebahn P.,Wuppertal Institute for Climate | Hao Z.,CAS Research Center for Eco Environmental Sciences
International Journal of Greenhouse Gas Control | Year: 2014

The main objective of this article is to evaluate CO2 mitigation potential and to calculate costs avoided by the use of different CO2 mitigation technologies in China's cement sector, namely energy efficiency improvements, use of alternative fuels, clinker substitution and carbon capture and storage (CCS). Three scenarios are designed based on the projection of cement output and technology development over the next 40 years (2010-2050). 2.5, 4.7 and 4.3Gttonnes of CO2 will be saved totally in basic scenario and two low carbon scenarios up to 2050. By comparing these technologies along the scenarios, it can be concluded that CO2 emissions can mainly be reduced by energy efficiency improvements and use of alternative fuels. Clinker substitution, which reduces the clinker-to-cement ratio as well as energy intensity, results in significant cost advantages. CCS, including post-combustion capture and oxy-fuel combustion capture, could play an important role in the capture of CO2 in the cement industry, and is expected to be in commercial use by 2030. © 2013.


Hou D.,CAS Research Center for Eco Environmental Sciences | Dai G.,Tsinghua University | Wang J.,CAS Research Center for Eco Environmental Sciences | Fan H.,Nanchang University | And 2 more authors.
Separation and Purification Technology | Year: 2012

The polyvinylidene fluoride (PVDF) flat-sheet composite membranes were prepared for membrane distillation using hydrophilic polyester nonwoven fabric as a support through coating and wet phase inversion process. The influence of non-solvent additive on membrane morphology, porosity, pore size and pore size distribution, hydrophobicity and permeability were evaluated. It was found that the membrane with a mixture of acetone and H 3PO 4 as non-solvent additive had a thinner top skin and a more porous network sponge-like layer from the morphology study. This membrane also exhibited a narrow pore size distribution and its mean pore size was about 0.22 μm in diameter. The rough membrane surface with smaller nodules produced a higher contact angle of 82.6 ± 0.7°with water according to atomic force microscope images analysis. During the direct contact membrane distillation (DCMD) process of 35 g/L sodium chloride solution, the maximum transmembrane permeate flux about 47.6 kg/m 2 h was obtained with the feed solution at 80.5 °C and the cold distillate water at 20.0°C. Furthermore, the membrane showed satisfying performance stability in the 240 h continuous desalination experiment, indicating that the prepared PVDF/nonwoven fabric flat-sheet composite membrane may be of great potential to be utilized in DCMD process for desalination.© 2012 Elsevier B.V. All rights reserved.


Qu G.,CAS Research Center for Eco Environmental Sciences | Liu S.,CAS Research Center for Eco Environmental Sciences | Zhang S.,CAS Research Center for Eco Environmental Sciences | Wang L.,CAS Research Center for Eco Environmental Sciences | And 7 more authors.
ACS Nano | Year: 2013

Graphene and graphene-based nanomaterials display novel and beneficial chemical, electrical, mechanical, and optical characteristics, which endow these nanomaterials with promising applications in a wide spectrum of areas such as electronics and biomedicine. However, its toxicity on health remains unknown and is of great concern. In the present study, we demonstrated that graphene oxide (GO) induced necrotic cell death to macrophages. This toxicity is mediated by activation of toll-like receptor 4 (TLR4) signaling and subsequently in part via autocrine TNF-α production. Inhibition of TLR4 signaling with a selective inhibitor prevented cell death nearly completely. Furthermore, TLR4-deficient bone marrow-derived macrophages were resistant to GO-triggered necrosis. Similarly, GO did not induce necrosis of HEK293T/TLR4-null cells. Macrophagic cell death upon GO treatment was partially attributed to RIP1-RIP3 complex-mediated programmed necrosis downstream of TNF-α induction. Additionally, upon uptake into macrophages, GO accumulated primarily in cytoplasm causing dramatic morphologic alterations and a significant reduction of the macrophagic ability in phagocytosis. However, macrophagic uptake of GO may not be required for induction of necrosis. GO exposure also caused a large increase of intracellular reactive oxygen species (ROS), which contributed to the cause of cell death. The combined data reveal that interaction of GO with TLR4 is the predominant molecular mechanism underlying GO-induced macrophagic necrosis; also, cytoskeletal damage and oxidative stress contribute to decreased viability and function of macrophages upon GO treatment. © 2013 American Chemical Society.


Yang X.,Florida State University | Chen L.,CAS Research Center for Eco Environmental Sciences
International Journal of Applied Earth Observation and Geoinformation | Year: 2010

Landslides are a major type of geohazards claiming thousands of casualties and billions of dollars in property damages every year. Catastrophic landslide activities are often triggered by some extreme events such as earthquakes, excessive precipitations, or volcanic eruptions. Quickly identifying the spatial distribution of landslides induced by these extreme events is crucial for coordinating rescue efforts and planning in situ investigations. In this study, we propose an automated method for detecting the spatial distribution of earthquake-triggered landslides by examining after-event vegetation changes. Central to this method is the use of pre- and post-event remote sensor images covering the same area. Geometric correction and radiometric normalization are performed before deriving a vegetation index from each image. Then, an image differencing procedure is applied to the two derived indices. With the resultant difference image, an initial landslide distribution map is generated by highlighting the pixels with a threshold percentage decrease in the brightness values as a direct result of the image subtraction. The threshold percentage value is interactively determined by using a visual interpretation method. The final landslide distribution map is produced after using a modal filter to suppress boundary errors in the initial map. This method has been implemented in a test site, approximately 30 km from the epicenter of the Sichuan earthquake (7.9. Ms) that struck on 12 May 2008. A pre-event Thematic Mapper image and a post-event Advanced Spaceborne Thermal Emission and Reflection Radiometer scene are used. The thematic accuracy assessment indicates that 90% of the landslides have correctly been mapped. Given the relatively simple procedures and the good mapping accuracy, the image processing and change detection method identified in this study seems to be promising from an operational perspective. © 2010 Elsevier B.V.


Li B.,Tsinghua University | Qiu Y.,Tsinghua University | Glidle A.,University of Glasgow | McIlvenna D.,University of Glasgow | And 4 more authors.
Analytical Chemistry | Year: 2014

Bacterial growth inhibition tests have become a standard measure of the adverse effects of inhibitors for a wide range of applications, such as toxicity testing in the medical and environmental sciences. However, conventional well-plate formats for these tests are laborious and provide limited information (often being restricted to an end-point assay). In this study, we have developed a microfluidic system that enables fast quantification of the effect of an inhibitor on bacteria growth and survival, within a single experiment. This format offers a unique combination of advantages, including long-term continuous flow culture, generation of concentration gradients, and single cell morphology tracking. Using Escherichia coli and the inhibitor amoxicillin as one model system, we show excellent agreement between an on-chip single cell-based assay and conventional methods to obtain quantitative measures of antibiotic inhibition (for example, minimum inhibition concentration). Furthermore, we show that our methods can provide additional information, over and above that of the standard well-plate assay, including kinetic information on growth inhibition and measurements of bacterial morphological dynamics over a wide range of inhibitor concentrations. Finally, using a second model system, we show that this chip-based systems does not require the bacteria to be labeled and is well suited for the study of naturally occurring species. We illustrate this using Nitrosomonas europaea, an environmentally important bacteria, and show that the chip system can lead to a significant reduction in the period required for growth and inhibition measurements (<4 days, compared to weeks in a culture flask). © 2014 American Chemical Society.


Fang J.,Zhejiang GongShang University | Shan X.-Q.,CAS Research Center for Eco Environmental Sciences | Wen B.,CAS Research Center for Eco Environmental Sciences | Lin J.-M.,Tsinghua University | And 2 more authors.
Environmental Pollution | Year: 2011

The effects of TiO2 nanoparticles on the transport of Cu through four different soil columns were studied. For two soils (HB and DX), TiO 2 nanoparticles acted as a Cu carrier and facilitated the transport of Cu. For a third soil (BJ) TiO2 nanoparticles also facilitated Cu transport but to a much lesser degree, but for a fourth soil (HLJ) TiO 2 nanoparticles retarded the transport of Cu. Linear correlation analysis indicated that soil properties rather than sorption capacities for Cu primary governed whether TiO2 nanoparticles-facilitated Cu transport. The TiO2-associated Cu of outflow in the Cu-contaminated soil columns was significantly positively correlated with soil pH and negatively correlated with CEC and DOC. During passage through the soil columns 46.6-99.9% of Cu initially adsorbed onto TiO2 could be "stripped" from nanoparticles depending on soil, where Cu desorption from TiO2 nanoparticles increased with decreasing flow velocity and soil pH. © 2011 Elsevier Ltd. All rights reserved.


Ma Y.,CAS Research Center for Eco Environmental Sciences | Hashi Y.,Shimadzu Global COE for Application and Technical Development | Ji F.,Shimadzu Global COE for Application and Technical Development | Lin J.-M.,Tsinghua University
Journal of Separation Science | Year: 2010

In this study, a simple, rapid and sensitive method for the determination of five phthalates including dimethyl phthalate, diethyl phthalate, dipropyl phthalate, benzyl butyl phthalate, and dicyclohexyl phthalate in fruit jellies by LC coupled with MS has been developed. Samples were pretreated by a dispersive SPE method, termed QuEChERS, which is an acronym for quick, easy, cheap, effective, rugged, and safe. The standard calibration curves were linear for all the analytes over the concentration range of 10-250 ng/mL, and the correlation coefficients ranged from 0.9976 to 0.9991. The LODs and LOQs were in the ranges of 0.09-3.68 ng/mL and 0.28-11.25 ng/mL, respectively. The accuracy of this method was evaluated by measuring the recovery from spiked samples. The recoveries of all five phthalates from samples spiked at three different concentrations (0.01, 0.03, and 0.05 mg/kg), were in the ranges of 83.5-103.9%, 86.7-95.8%, and 87.1-95.2%, respectively. The RSD values for the samples spiked at 0.01, 0.03 , and 0.05 mg/kg ranged from 2.0-7.6%, 1.4-6.4%, and 1.2-3.8%, respectively. The method has been used for the analysis of real samples and BBP and DEP were found in real samples. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.


Wang Z.,CAS Research Center for Eco Environmental Sciences | Wang Z.,Tufts University | Xia T.,University of California at Los Angeles | Liu S.,CAS Research Center for Eco Environmental Sciences
Nanoscale | Year: 2015

Due to its unique physicochemical properties and remarkable antimicrobial activity, nanosilver (nAg) is increasingly being used in a wide array of fields, including medicine and personal care products. Despite substantial progress being made towards the understanding of the acute toxicity of nAg, large knowledge gaps still exist on the assessment of its chronic toxicity to humans. Chronic effects of nAg, typically at low doses (i.e. sublethal doses) should be different from the acute toxicity at high doses (i.e., lethal doses), which is analogous to other environmental pollutants. Although a few review papers have elaborated the findings on nAg-mediated toxicity, most of them only discussed overt toxicity of nAg at high-level exposure and failed to evaluate the chronic and cumulative effects of nAg at sublethal doses. Therefore, it is necessary to more stringently scrutinize the sublethal toxicity of nAg under environmentally relevant conditions. Herein, we recapitulated recent findings on the sublethal effects of nAg toxicity performed by our groups and others. We then discussed the molecular mechanisms by which nAg exerts its toxicity under low concentrations and compared that with nAg-induced cell death. © The Royal Society of Chemistry 2015.


Wang A.,Tohoku University | Wang A.,CAS Research Center for Eco Environmental Sciences | Li Y.-Y.,Tohoku University | Li Y.-Y.,Tianjin Institute of Urban Construction | Estrada A.L.,Tohoku University
Applied Catalysis B: Environmental | Year: 2011

The mineralization of antibiotic sulfamethoxazole (SMX) of concentrations up to 300mgL-1 was examined by photoelectro-Fenton (PEF) using an activated carbon fiber (ACF) cathode with UVA (365nm) irradiation. Comparative mineralization has been studied by different methods: RuO2/Ti anodic oxidation (AO), AO in the presence of electrogenerated H2O2 (AO-H2O2), AO-H2O2 in the presence of UVA (AO-H2O2-UVA), and both the electro-Fenton (EF) and PEF processes. PEF treatment at a low applied current of 0.36A yields a faster and more complete depollution with 80% of the TOC removed after 6h of electrolysis. The higher oxidative ability of the PEF process can be attributed to the additional hydroxyl radicals (·OH) produced by the photo-Fenton reaction. The 63% mineralization in the case of EF treatment was due to the formation of short intermediates, such as carboxylic acids, which were difficult to oxidise with ·OH. In the AO-H2O2-UVA process, about 36% of the TOC was removed after 6h electrolysis, while 28% of the TOC was removed in the AO-H2O2 process. SMX is only slightly mineralized by the AO process, with only 25% of the TOC removed. HPLC-MS analysis allowed for up to six aromatic reaction products to be identified during the SMX degradation in the PEF process, mainly formed from the hydroxylation of the aromatic ring or/and isoxazole ring, accompanied by the substitution of the amine group (on aromatic cycle) or methyl group (on isoxazole ring) by ·OH. The carboxylic acids generated, including oxalic, maleic, oxamic, formic and acetic acids, were detected by ion-exclusion chromatography. The initial organic nitrogen was mainly converted into NH4 + along with a very small proportion of NO3 - ion. Considering all the oxidation intermediates and end products for SMX degradation in the PEF process, a general mineralization mechanism by ·OH and UVA was proposed. © 2010 Elsevier B.V.


Suragani R.N.V.S.,Harvard-MIT Division of Health Sciences and Technology | Zachariah R.S.,Harvard-MIT Division of Health Sciences and Technology | Velazquez J.G.,Harvard-MIT Division of Health Sciences and Technology | Liu S.,Harvard-MIT Division of Health Sciences and Technology | And 4 more authors.
Blood | Year: 2012

Heme-regulated eIF2α kinase (Hri) is necessary for balanced synthesis of heme and globin. In addition, Hri deficiency exacerbates the phenotypic severity of β-thalassemia intermedia in mice. Activation of Hri during heme deficiency and in β-thalassemia increases eIF2α phosphorylation and inhibits globin translation. Under endoplasmic reticulum stress and nutrient starvation, eIF2α phosphorylation also induces the Atf4 signaling pathway to mitigate stress. Although the function of Hri in regulating globin translation is well established, its role in Atf4 signaling in erythroid precursors is not known. Here, we report the role of the Hri-activated Atf4 signaling pathway in reducing oxidative stress and in promoting erythroid differentiation during erythropoiesis. On acute oxidative stress, Hri -/-erythroblasts suffered from increased levels of reactive oxygen species (ROS) and apoptosis. During chronic iron deficiency in vivo, Hri is necessary both to reduce oxidative stress and to promote erythroid differentiation. Hri -/- mice developed ineffective erythropoiesis during iron deficiency with inhibition of differentiation at the basophilic erythroblast stage. This inhibition is recapitulated during ex vivo differentiation of Hri -/- fetal liver erythroid progenitors. Importantly, the HrieIF2αP-Atf4 pathway was activated and required for erythroid differentiation. We further demonstrate the potential of modulating Hri-eIF2αP-Atf4 signaling with chemical compounds as pharmaceutical therapies for β-thalassemia. © 2012 by The American Society of Hematology.


Li D.,CAS Research Center for Eco Environmental Sciences | Li Z.,CAS Research Center for Eco Environmental Sciences | Yu J.,CAS Research Center for Eco Environmental Sciences | Cao N.,Water Quality Monitoring Center | And 2 more authors.
Applied and Environmental Microbiology | Year: 2010

The role of bacteria in the occasional emergence of red water, which has been documented worldwide, has yet to be determined. To better understand the mechanisms that drive occurrences of red water, the bacterial community composition and the relative abundance of several functional bacterial groups in a water distribution system of Beijing during a large-scale red water event were determined using several molecular methods. Individual clone libraries of the 16S rRNA gene were constructed for three red water samples and one sample of normal water. Beta-, Alpha-, and Gammaproteobacteria comprised the major bacterial communities in both red water and normal water samples, in agreement with previous reports. A high percentage of red water clones (25.2 to 57.1%) were affiliated with or closely related to a diverse array of iron-oxidizing bacteria, including the neutrophilic microaerobic genera Gallionella and Sideroxydans, the acidophilic species Acidothiobacillus ferrooxidans, and the anaerobic denitrifying Thermomonas bacteria. The genus Gallionella comprised 18.7 to 28.6% of all clones in the three red water libraries. Quantitative real-time PCR analysis showed that the 16S rRNA gene copy concentration of Gallionella spp. was between (4.1 ± 0.9) × 107 (mean ± standard deviation) and (1.6 ± 0.3) × 108 per liter in red water, accounting for 13.1% ± 2.9% to 17.2% ± 3.6% of the total Bacteria spp. in these samples. By comparison, the percentages of Gallionella spp. in the normal water samples were 0.1% or lower (below the limit of detection), suggesting an important role of Gallionella spp. in the formation of red water. Copyright © 2010, American Society for Microbiology.


Yang L.,CAS Research Center for Eco Environmental Sciences | Wei W.,CAS Research Center for Eco Environmental Sciences | Chen L.,CAS Research Center for Eco Environmental Sciences | Chen W.,Syngenta | Wang J.,Tsinghua University
Catena | Year: 2014

Soil moisture is fundamental to ecosystem sustainability in semi-arid regions, and characterizing the response of temporal soil moisture variation to different vegetation types is important for assessing the sustainability of vegetation restoration. In this study, the soil moisture among eight typical types of vegetation is investigated and compared during three rainy seasons. The temporal variations of soil moisture in the near-surface (0-0.4. m), sub-surface (0.4-1.0. m), and deep layers (1.0-2.0. m) are explored to evaluate the ecohydrological effect of vegetation restoration in the semi-arid Loess Plateau of China. The results show that soil moisture content decreases drastically after vegetation restoration, with no significant difference in near-surface soil moisture among the vegetation types but significant differences in the sub-surface and deep soil layers. Introduced vegetation is the main factor affecting the soil moisture deficit below near-surface layers. Secondly, soil moisture is temporally stable in the sub-surface and deep layers, especially in introduced vegetation. This indicates that introduced vegetation consumes excessive amount of soil moisture and induces temporally stable soil desiccation. Soil desiccation with temporal stability cannot provide enough available soil moisture for plants and will inevitably threaten the sustainability of vegetation restoration and the associated ecosystem services. Lastly, high planting density is the main cause of severe soil moisture deficit on a long-term temporal scale. Our study results suggest that the current planting density of introduced vegetation is too high in specific cases and should be optimized with local soil moisture conditions in semi-arid regions. © 2013 Elsevier B.V.


Meng M.,CAS Research Center for Eco Environmental Sciences | Li B.,Chinese Research Academy of Environmental Sciences | Shao J.-J.,CAS Research Center for Eco Environmental Sciences | Wang T.,CAS Research Center for Eco Environmental Sciences | And 4 more authors.
Environmental Pollution | Year: 2014

A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk & leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants. © 2013 Elsevier Ltd. All rights reserved.


Sun M.,CAS Research Center for Eco Environmental Sciences | Sun M.,University of Chinese Academy of Sciences | Liu H.,CAS Research Center for Eco Environmental Sciences | Liu Y.,Tsinghua University | And 2 more authors.
Nanoscale | Year: 2015

The development of low cost, durable and efficient nanocatalysts to substitute expensive and rare noble metals (e.g. Pt, Au and Pd) in overcoming the sluggish kinetic process of the oxygen reduction reaction (ORR) is essential to satisfy the demand for sustainable energy conversion and storage in the future. Graphene based transition metal oxide nanocomposites have extensively been proven to be a type of promising highly efficient and economic nanocatalyst for optimizing the ORR to solve the world-wide energy crisis. Synthesized nanocomposites exhibit synergetic advantages and avoid the respective disadvantages. In this feature article, we concentrate on the recent leading works of different categories of introduced transition metal oxides on graphene: from the commonly-used classes (FeOx, MnOx, and CoOx) to some rare and heat-studied issues (TiOx, NiCoOx and Co-MnOx). Moreover, the morphologies of the supported oxides on graphene with various dimensional nanostructures, such as one dimensional nanocrystals, two dimensional nanosheets/nanoplates and some special multidimensional frameworks are further reviewed. The strategies used to synthesize and characterize these well-designed nanocomposites and their superior properties for the ORR compared to the traditional catalysts are carefully summarized. This work aims to highlight the meaning of the multiphase establishment of graphene-based transition metal oxide nanocomposites and its structural-dependent ORR performance and mechanisms. © 2015 The Royal Society of Chemistry.


Sun G.-X.,CAS Research Center for Eco Environmental Sciences | Liu X.,CAS Research Center for Eco Environmental Sciences | Liu X.,University of Aberdeen | Williams P.N.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Environmental Science and Technology | Year: 2010

Selenium, an essential micronutrient for humans, is insufficient in dietary intake for millions of people worldwide. Rice as the most popular staple food in the world is one of the dominant selenium (Se) sources for people. The distribution and translocation of Se from soil to grain were investigated in a Se-rich environment in this study. The Se levels in soils ranged widely from 0.5 to 47.7 mg kg-1. Selenium concentration in rice bran was 1.94 times higher than that in corresponding polished rice. The total Se concentrations in the rice fractions were in the following order: straw > bran > whole grain > polished rice > husk. Significant linear relationships between different rice fractions were observed with each other, and Se in the soil has a linear relationship with different rice fractions as well. Se concentration in rice can easily be predicted by soil Se concentrations or any rice fractions and vice versa according to their linear relationships. In all rice samples for Se speciation, SeMet was the major Se species, followed by MeSeCys and SeCys. The average percentage for SeMet (82.9%) and MeSeCys (6.2%) was similar in the range of total Se from 2.2 to 8.4 mg kg-1 tested. The percentage of SeCys decreased from 6.3 to 2.8%, although its concentration elevated with the increase in total Se in rice. This could be due to the fact that SeCys is the precursor for the formation of other organic Se compounds. The information obtained may have considerable significance for assessing translocation and accumulation of Se in plant. © 2010 American Chemical Society.


Xu W.,University of Jinan | Xu W.,CAS Research Center for Eco Environmental Sciences | Yue Q.,Shandong University | Gao B.,Shandong University | Du B.,University of Jinan
Desalination | Year: 2015

Effects of polydimethyldiallylammonium chloride (PD) on coagulation behaviors of different Al-based coagulants were investigated in coagulation-ultrafiltration (C-UF) hybrid process, regarding the impurity removal efficiency, floc properties and membrane foulings. Floc characteristics, including floc size, compact degree, strength and re-growth ability were studied using a laser diffraction particle sizing device. Resistance analyses were implemented to explore the membrane fouling mechanisms. The results indicated that PD aid could increase the purification efficiency of C-UF, especially at low coagulant doses. PD-alum/PD-PACl contributed to large flocs, while alum-PD/PACl-PD gave rise to flocs with high Rf and Df values. The results of ultrafiltration experiments showed that conventional coagulant, i.e., alum led to a flux reduction of 52%; while the reductions for alum-PD and PD-alum were 53% and 34%, respectively. The flux reductions for PACl, PACl-PD and PD-PACl were 60%, 57% and 39%. Flux declines became more severe when the coagulated suspensions were exposed to increased shears and the suspensions coagulated by aluminum plus PD resulted in the least reductions in fluxes. © 2014 Elsevier B.V.


Tian Z.,CAS Research Center for Eco Environmental Sciences | Zhang Y.,CAS Research Center for Eco Environmental Sciences | Li Y.,Tohoku University | Chi Y.,CAS Research Center for Eco Environmental Sciences | Yang M.,CAS Research Center for Eco Environmental Sciences
Water Research | Year: 2015

The purpose of this study was to explore how fast the thermophilic anaerobic microbial community could be established during the one-step startup of thermophilic anaerobic digestion from a mesophilic digester. Stable thermophilic anaerobic digestion was achieved within 20 days from a mesophilic digester treating sewage sludge by adopting the one-step startup strategy. The succession of archaeal and bacterial populations over a period of 60 days after the temperature increment was followed by using 454-pyrosequencing and quantitative PCR. After the increase of temperature, thermophilic methanogenic community was established within 11 days, which was characterized by the fast colonization of Methanosarcina thermophila and two hydrogenotrophic methanogens (. Methanothermobacter spp. and Methanoculleus spp.). At the same time, the bacterial community was dominated by Fervidobacterium, whose relative abundance rapidly increased from 0 to 28.52 % in 18 days, followed by other potential thermophilic genera, such as Clostridium, Coprothermobacter, Anaerobaculum and EM3. The above result demonstrated that the one-step startup strategy could allow the rapid establishment of the thermophilic anaerobic microbial community. © 2014 Elsevier Ltd.


Fang J.,Zhejiang GongShang University | Xu M.-J.,Zhejiang GongShang University | Wang D.-J.,CAS Nanjing Institute of Soil Science | Wen B.,CAS Research Center for Eco Environmental Sciences | Han J.-Y.,Zhejiang GongShang University
Water Research | Year: 2013

This study aims to explore the mechanisms governing the transport and retention kinetics of TiO2 nanoparticle aggregates (NPAs) in flow-through columns of packed sand, particularly under unsaturated conditions. The study was carried out at different pHs (2.6, 7.1, and 9.6) and ionic strengths (ISs) (1.0, 10, and 50 mM). A two-site kinetic attachment model was used to describe transport behaviors of TiO2 NPAs. At low ISs (i.e., 1.0 and 10 mM) and in neutral/alkaline conditions, high mobility of TiO2 NPAs was observed in both saturated and unsaturated conditions. However, the retention of TiO2 NPAs was substantially enhanced at the high IS (50 mM) and in extremely acidity condition (pH = 2.6), because of increased aggregation and straining of TiO2 NPAs during their transport course. The breakthrough curves (BTCs) of TiO2 NPAs under unsaturated and saturated conditions almost overlapped, suggesting that decreasing the water saturation did not enhance the retention of TiO2 NPAs in sand columns. This was probably due to the repulsive interactions existed between negatively charged air-water and TiO2 NPAs systems that resulted in unfavorable attachment conditions. The two-site kinetic attachment model provided a good description for the BTCs of TiO2 NPAs both in saturated and unsaturated conditions. The fitted parameters could successfully explain the transport behaviors of TiO2 NPAs under various solution chemistries. © 2012 Elsevier Ltd.


Yao H.,Zhejiang University | Gao Y.,Zhejiang University | Nicol G.W.,University of Aberdeen | Campbell C.D.,James Hutton Institute | And 6 more authors.
Applied and Environmental Microbiology | Year: 2011

Ammonia oxidation is the first and rate-limiting step of nitrification and is performed by both ammoniaoxidizing archaea (AOA) and bacteria (AOB). However, the environmental drivers controlling the abundance, composition, and activity of AOA and AOB communities are not well characterized, and the relative importance of these two groups in soil nitrification is still debated. Chinese tea orchard soils provide an excellent system for investigating the long-term effects of low pH and nitrogen fertilization strategies. AOA and AOB abundance and community composition were therefore investigated in tea soils and adjacent pine forest soils, using quantitative PCR (qPCR), terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of respective ammonia monooxygenase (amoA) genes. There was strong evidence that soil pH was an important factor controlling AOB but not AOA abundance, and the ratio of AOA to AOB amoA gene abundance increased with decreasing soil pH in the tea orchard soils. In contrast, T-RFLP analysis suggested that soil pH was a key explanatory variable for both AOA and AOB community structure, but a significant relationship between community abundance and nitrification potential was observed only for AOA. High potential nitrification rates indicated that nitrification was mainly driven by AOA in these acidic soils. Dominant AOA amoA sequences in the highly acidic tea soils were all placed within a specific clade, and one AOA genotype appears to be well adapted to growth in highly acidic soils. Specific AOA and AOB populations dominated in soils at particular pH values and N content, suggesting adaptation to specific niches. © 2011, American Society for Microbiology.


Han J.,Zhejiang GongShang University | Han J.,Wageningen University | Han J.,CAS Research Center for Eco Environmental Sciences | Mol A.P.J.,Wageningen University | Lu Y.,CAS Research Center for Eco Environmental Sciences
Energy Policy | Year: 2010

Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively affluent province, as a case study area to assess the performance of solar water heater utilization in China. The study will focus on institutional setting, economic and technological performance, energy performance, and environmental and social impact. Results show that China has greatly increased solar water heater utilization, which has brought China great economic, environmental and social benefits. However, China is confronted with malfeasant market competition, technical flaws in solar water heater products and social conflict concerning solar water heater installation. For further development of the solar water heater, China should clarify the compulsory installation policy and include solar water heaters into the current "Home Appliances Going to the Countryside" project; most of the widely used vacuum tube products should be replaced by flat plate products, and the technology improvement should focus on anti-freezing and water saving; the resources of solar water heater market should be consolidated and most of the OEM manufacturers should evolve to ODM and OBM enterprises. © 2009 Elsevier Ltd. All rights reserved.


Wang X.,CAS Research Center for Eco Environmental Sciences | McCarty P.L.,Stanford University | Liu J.,CAS Research Center for Eco Environmental Sciences | Ren N.-Q.,Harbin Institute of Technology | And 4 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

Global or expectations for wastewater service infrastructure have evolved over time, and the standard treatment methods used by wastewater treatment plants (WWTPs) are facing issues related to problem shifting due to the current emphasis on sustainability. A transition in WWTPs toward reuse of wastewater-derived resources is recognized as a promising solution for overcoming these obstacles. However, it remains uncertain whether this approach can reduce the environmental footprint of WWTPs. To test this hypothesis, we conducted a net environmental benefit calculation for several scenarios for more than 50 individual countries over a 20-y time frame. For developed countries, the resource recovery approach resulted in ∼154% net increase in the environmental performance of WWTPs compared with the traditional substance elimination approach, whereas this value decreased to ∼60% for developing countries. Subsequently, we conducted a probabilistic analysis integrating these estimates with national values and determined that, if this transition was attempted for WWTPs in developed countries, it would have a ∼65% probability of attaining net environmental benefits. However, this estimate decreased greatly to ∼10% for developing countries, implying a substantial risk of failure. These results suggest that implementation of this transition for WWTPs should be studied carefully in different temporal and spatial contexts. Developing countries should customize their approach to realizing more sustainable WWTPs, rather than attempting to simply replicate the successful models of developed countries. Results derived from the model forecasting highlight the role of bioenergy generation and reduced use of chemicals in improving the sustainability of WWTPs in developing countries.


Wu C.,Hong Kong Baptist University | Ye Z.,Sun Yat Sen University | Shu W.,Sun Yat Sen University | Zhu Y.,CAS Research Center for Eco Environmental Sciences | Wong M.,Hong Kong Baptist University
Journal of Experimental Botany | Year: 2011

Root aeration, arsenic (As) accumulation, and speciation in rice of 20 different genotypes with regular irrigation of water containing 0.4 mg As l -1 were investigated. Different genotypes had different root anatomy demonstrated by entire root porosity (ranging from 12.43% to 33.21%), which was significantly correlated with radial oxygen loss (ROL) (R=0.64, P<0.01). Arsenic accumulation differed between genotypes, but there were no significant differences between Indica and Japonica subspecies, as well as paddy and upland rice. Total ROL from entire roots was correlated with metal tolerance (expressed as percentage mean of control straw biomass, R=0.69, P<0.01) among the 20 genotypes; total As concentration (R=-0.67, P<0.01) and inorganic As concentration (R=-0.47, P<0.05) in rice grains of different genotypes were negatively correlated with ROL. There were also significant genotype effects in percentage inorganic As (F=15.8, P<0.001) and percentage cacodylic acid (F=22.1, P<0.001), respectively. Root aeration of different genotypes and variation of genotypes on As accumulation and speciation would be useful for selecting genotypes to grow in areas contaminated by As. © 2011 The Author(s).


Hou D.,CAS Research Center for Eco Environmental Sciences | Dai G.,Tsinghua University | Fan H.,Nanchang University | Wang J.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Desalination | Year: 2014

The polyvinylidene fluoride (PVDF) flat-sheet composite membranes were prepared for membrane distillation using hydrophilic polyester nonwoven fabric as a support and the mixture of LiCl and PEG as non-solvent additive through coating and wet phase inversion process. The effects of hydrophobic calcium carbonate nano-particles on membrane morphology, porosity, pore size, pore size distribution, hydrophobicity, thermal properties and permeability were investigated. The nano-particles optimized membrane structure, enlarged pore diameter, narrowed pore size distribution and improved membrane porosity to some extent. In addition, the nano-particles could also enhance membrane surface roughness and contact angle while increasing the crystallinity degree of the prepared membranes. Nonetheless, the excess nano-particles addition would deteriorate membrane structure, reduce membrane porosity and decrease pore size. During the desalination process of 35g/L sodium chloride solution, the maximum transmembrane permeate flux about 49.37kg/m2h was obtained with the feed solution at 83C and the cold distillate water at 20.0C. Furthermore, the flat-sheet composite membrane exhibited satisfying performance stability compared with the membrane without nano-particles addition in the 300h continuous desalination experiments, indicating that the prepared PVDF/nonwoven fabric flat-sheet composite membrane may be of great potential to be utilized in membrane distillation process for desalination. © 2014 Elsevier B.V.


Tian F.,CAS Research Center for Eco Environmental Sciences | Qiu G.,University of Science and Technology of China | Lu Y.,CAS Research Center for Eco Environmental Sciences | Yang Y.,CAS Institute of Genetics and Developmental Biology | Xiong Y.,Sun Yat Sen University
Journal of Hydrology | Year: 2014

Based on high-resolution thermal infrared remote sensing and the three-temperature model (3T model), we developed a new algorithm for mapping transpiration. The necessary input parameters were surface temperature, air temperature, and solar radiation only. Therefore, in comparison with conventional methods, it is a simple and potentially valuable way to employ the thermal infrared remote sensing application. By using the proposed method, transpiration of sixteen types of typical vegetation in the upper and middle reaches of the Heihe River Basin in Northwestern China were calculated pixel by pixel. We evaluated modeled evapotranspiration with an eddy covariance (EC) result from the established regression equation, and a scatter correlation plot for the measured and estimated transpiration indicated that the model estimate is within acceptable limits, with a correlation coefficient of R2=0.796. Compared with the desert-oasis transitional zone, the maximum transpiration rate at the Gobi Desert presented a little earlier but was smaller. This great difference may imply that different types of plants have different water-use abilities and drought tolerances. Thus, the transpiration estimation with the 3T model, using high-resolution thermal infrared remote sensing data, can provide not only a bridge between large-scale and point observation with a measure of m2 from the infrared thermal imager, but also provide decision support for operational water management issues. © 2014 Elsevier B.V.


Zhang S.,CAS Research Center for Eco Environmental Sciences | Zhang S.,Massachusetts Institute of Technology | Chen Y.,CAS Research Center for Eco Environmental Sciences | Chen Y.,Tianjin Medical University | And 7 more authors.
Cellular Signalling | Year: 2014

Iron homeostasis is strictly governed in mammals; however, disordered iron metabolism (such as excess iron burden) is recognized as a risk factor for various types of diseases including cancers. Burgeoning evidence indicates that the central signaling of iron homeostasis, the hepcidin-ferroportin axis, is misregulated in cancers. Nonetheless, the mechanisms of misregulated expression of iron-related genes along this signaling in cancers remain largely unknown. In the current study, we found increased levels of serum hepcidin in breast cancer patients. Reduction of hepatic hepcidin through administration of heparin restrained tumorigenic properties of breast tumor cells. Mechanistic investigation revealed that increased iron, bone morphogenetic protein-6 (BMP6) and interleukin-6 (IL-6) jointly promoted the synthesis of hepatic hepcidin. Tumor hepcidin expression was marginally increased in breast tumors relative to adjacent tissues. In contrast, tumor ferroportin concentration was greatly reduced in breast tumors, especially in malignant tumors, compared to adjacent tissues. Elevation of ferroportin concentration inhibited cell proliferation in vitro and in vivo by knocking down tumor hepcidin expression. Additionally, increased IL-6 was demonstrated to jointly enhance the tumorigenic effects of iron through enforcing cell growth. Our combined data overall deciphered the machinery that altered the hepcidin-ferroportin signaling in breast cancers. Thus, targeting the hepcidin-ferroportin signaling would represent a promising therapeutics to restrain breast cancer growth. © 2014 Elsevier Inc.


Khan S.,University of Peshawar | Khan S.,CAS Research Center for Eco Environmental Sciences | Hesham A.E.-L.,Assiut University | Qiao M.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Environmental Science and Pollution Research | Year: 2010

Background, aim, and scope: Soil contamination with heavy metals occurs as a result of both anthropogenic and natural activities. Heavy metals could have long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. Soil enzymatic activities are recognized as sensors towards any natural and anthropogenic disturbance occurring in the soil ecosystem. Similarly, microbial biomass carbon (MBC) is also considered as one of the important soil biological activities frequently influenced by heavy metal contamination. The polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) has recently been used to investigate changes in soil microbial community composition in response to environmental stresses. Soil microbial community structure and activities are difficult to elucidate using single monitoring approach; therefore, for a better insight and complete depiction of the soil microbial situation, different approaches need to be used. This study was conducted in a greenhouse for a period of 12 weeks to evaluate the changes in indigenous microbial community structure and activities in the soil amended with different application rates of Cd, Pb, and Cd/Pb mix. In a field environment, soil is contaminated with single or mixed heavy metals; so that, in this research, we used the selected metals in both single and mixed forms at different application rates and investigated their toxic effects on microbial community structure and activities, using soil enzyme assays, plate counting, and advanced molecular DGGE technique. Soil microbial activities, including acid phosphatase (ACP), urease (URE), and MBC, and microbial community structure were studied. Materials and methods: A soil sample (0-20 cm) with an unknown history of heavy metal contamination was collected and amended with Cd, Pb, and Cd/Pb mix using the CdSO4 and Pb(NO3)2 solutions at different application rates. The amended soils were incubated in the greenhouse at 25±4°C and 60% water-holding capacity for 12 weeks. During the incubation period, samples were collected from each pot at 0, 2, 9, and 12 weeks for enzyme assays, MBC, numeration of microbes, and DNA extraction. Fumigation-extraction method was used to measure the MBC, while plate counting techniques were used to numerate viable heterotrophic bacteria, fungi, and actinomycetes. Soil DNAs were extracted from the samples and used for DGGE analysis. Results: ACP, URE, and MBC activities of microbial community were significantly lower (p < 0.05) in the metal-amended samples than those in the control. The enzyme inhibition extent was obvious between different incubation periods and varied as the incubation proceeded, and the highest rate was detected in the samples after 2 weeks. However, the lowest values of ACP and URE activities (35.6% and 36.6% of the control, respectively) were found in the Cd3/Pb3-treated sample after 2 weeks. Similarly, MBC was strongly decreased in both Cd/Pb-amended samples and highest reduction (52.4%) was detected for Cd3/Pb3 treatment. The number of bacteria and actinomycetes were significantly decreased in the heavy metal-amended samples compared to the control, while fungal cells were not significantly different (from 2.3% to 23.87%). In this study, the DGGE profile indicated that the high dose of metal amendment caused a greater change in the number of bands. DGGE banding patterns confirmed that the addition of metals had a significant impact on microbial community structure. Discussion: In soil ecosystem, heavy metals exhibit toxicological effects on soil microbes which may lead to the decrease of their numbers and activities. This study demonstrated that toxicological effects of heavy metals on soil microbial community structure and activities depend largely on the type and concentration of metal and incubation time. The inhibition extent varied widely among different incubation periods for these enzymes. Furthermore, the rapid inhibition in microbial activities such as ACP, URE, and MBC were observed in the 2 weeks, which should be related to the fact that the microbes were suddenly exposed to heavy metals. The increased inhibition of soil microbial activities is likely to be related to tolerance and adaptation of the microbial community, concentration of pollutants, and mechanisms of heavy metals. The DGGE profile has shown that the structure of the bacterial community changed in amended heavy metal samples. In this research, the microbial community structure was highly affected, consistent with the lower microbial activities in different levels of heavy metals. Furthermore, a great community change in this study, particularly at a high level of contamination, was probably a result of metal toxicity and also unavailability of nutrients because no nutrients were supplied during the whole incubation period. Conclusions: The added concentrations of heavy metals have changed the soil microbial community structure and activities. The highest inhibitory effects on soil microbial activities were observed at 2 weeks of incubation. The bacteria were more sensitive than actinomycetes and fungi. The DGGE profile indicated that bacterial community structure was changed in the Cd/Pb-amended samples, particularly at high concentrations. Recommendations and perspectives: The investigation of soil microbial community structure and activities together could give more reliable and accurate information about the toxic effects of heavy metals on soil health. © Springer-Verlag 2009.


Fang J.,Zhejiang GongShang University | Shan X.-Q.,CAS Research Center for Eco Environmental Sciences | Wen B.,CAS Research Center for Eco Environmental Sciences | Huang R.-X.,Baylor University
Geoderma | Year: 2013

The transport behavior of TX100 suspended multiwalled carbon nanotubes (MWCNTs) through different soil columns as well as their effects on the mobility of phenanthrene was systematically studied. Results showed that the mobility of MWCNTs varied with soils, which was found to be correlated positively to the average soil particle diameters and soil sand contents, while correlated negatively to soil clay contents. The retention of MWCNTs on soil columns is most likely due to surface deposition and physical straining. Co-transport of phenanthrene with MWCNTs was tested in three selected soils (soil HB, DX and BJ), where MWCNTs could act as carriers of phenanthrene and enhance the mobility of phenanthrene in soils. However, during passing through the soil columns phenanthrene initially adsorbed onto MWCNTs could be partially "stripped" off. In soil with the lowest phenanthrene sorption affinity and highest water velocity (soil HB), only 8.5% phenanthrene was desorbed during transport, suggesting that a strong MWCNT-associated phenanthrene mobile may occur in this soil. More than 80% of phenanthrene was stripped off in soils with higher sorption affinity (soil DX and BJ), indicating the limitation of the co-transport of phenanthrene and MWCNTs in such soils. © 2013 The Authors.


Han X.B.,CAS Research Center for Eco Environmental Sciences | Han X.B.,Shenzhen Water Group CO. | Yuen K.W.Y.,University of Hong Kong | Wu R.S.S.,University of Hong Kong
Environmental Pollution | Year: 2013

Polybrominated diphenyl ethers (PBDEs) have been commonly used as flame retardants and now become ubiquitous in the global environment. Using zebrafish as a model, we tested the hypothesis that PBDEs may affect the reproduction and development of fish. Zebrafish were exposed to environmentally relevant concentrations of DE-71 (a congener of PBDE commonly found in the environment) throughout their whole life cycle, and the effects of DE-71 on gonadal development, gamete quality, fertilization success, hatching success, embryonic development and sex ratio were investigated. Despite gonadal development was enhanced, reductions in spawning, fertilization success, hatching success and larval survival rate were evident, while significant increases in malformation and percentage of male were also observed in the F1 generation. Our laboratory results suggest that PBDEs may pose a risk to reproductive success and alter the sex ratio of fish in environments highly contaminated with PBDEs. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.


Xiong L.-Y.,Nanjing Normal University | Tang G.-A.,Nanjing Normal University | Li F.-Y.,Nanjing Normal University | Yuan B.-Y.,CAS Institute of Geology and Geophysics | Lu Z.-C.,CAS Research Center for Eco Environmental Sciences
Geomorphology | Year: 2014

The evolution of loess-covered landforms is largely controlled by the pre-Quaternary underlying bedrock terrain, which is one of the most important factors in understanding the formation mechanism of the landforms. This study used multiple data sources to detect 1729 outcropping points of underlying terrain, in order to construct a digital elevation model (DEM) of the paleotopography of an area of the Loess Plateau subject to severe soil erosion. Four terrain characteristics, including terrain texture, slope gradient, the hypsometric curve, and slope aspect, were used to quantify topographic differences and reveal the loess-deposition process during the Quaternary. A loess thickness map was then created to show the spatial distribution of loess deposits in the test area. Finally, the geomorphological inheritance characteristics of the loess-covered landforms were evaluated in different landform divisions. The results showed the significant inheritance of modern topography from the underlying topography with a similar general relief trends. The average thickness of loess deposits was computed to be 104.6. m, with the thickest part located in the Xifeng loess tableland area. In addition, the slope aspects of the North and Northwest seem to have favored Quaternary loess deposition, which supported the hypothesis of an eolian origin for loess in China. The modern surface has lower topographic relief compared to the underlying terrain due to loess deposition. © 2013.


Zhang B.-T.,CAS Research Center for Eco Environmental Sciences | Lin J.,Tsinghua University
Luminescence | Year: 2010

The chemiluminescence (CL) phenomena of lanthanide (Ln) ions and their coordinate complexes in peroxomonosulfate system and the energy transfer mechanism during the process were investigated in this work. A strong and sharp CL signal was yielded when the Eu(III) or Tb(III) solution was added to the peroxymonosulfate solution. The CL intensity was greatly enhanced by 2,6-pyridinedicarboxylic acid (DPA) ligand [maximum enhancement reached when Ln(III):DPA was 1:1] and hexadecyltrimethylammonium chloride micelles. The degree of enhancement of DPA and micelles on Ln(III) CL was related to the fluorescence lifetimes of Ln(III) in different media. According to the ESR spin-trapping experiments of 2,2,6,6- tetramethyl-4-piperidone and the specific quenching experiments of 1,4-diazabicyclo[2.2.2]octane and sodium azide, singlet oxygen was generated though the Ln(III) ion-catalyzed decomposition of peroxymonosulfate. From the comparisons of the fluorescence and CL spectra, lanthanide ions were the luminescence emitter and the ligand DPA absorbed the energy from singlet oxygen and transferred it to Ln(III) ions in the coordinate complexes. Micelles can enhance the CL intensity by improving intermolecular energy transfer efficiencies, removing the quenching effect of water and prolonging the lifetime of singlet oxygen. © 2009 John Wiley & Sons, Ltd.


Carlton E.J.,University of California at Berkeley | Liang S.,University of Florida | McDowell J.Z.,Emory University | Li H.,U.S. Center for Disease Control and Prevention | And 2 more authors.
Bulletin of the World Health Organization | Year: 2012

Objective To estimate the disease burden attributable to unsafe water and poor sanitation and hygiene in China, to identify high-burden groups and to inform improvement measures. Methods The disease burden attributable to unsafe water and poor sanitation and hygiene in China was estimated for diseases resulting from exposure to biologically contaminated soil and water (diarrhoeal disease, helminthiases and schistosomiasis) and vector transmission resulting from inadequate management of water resources (malaria, dengue and Japanese encephalitis). The data were obtained from China's national infectious disease reporting system, national helminthiasis surveys and national water and sanitation surveys. The fraction of each health condition attributable to unsafe water and poor sanitation and hygiene in China was estimated from data in the Chinese and international literature. Findings In 2008, 327 million people in China lacked access to piped drinking water and 535 million lacked access to improved sanitation. The same year, unsafe water and poor sanitation and hygiene accounted for 2.81 million disability-adjusted life years (DALYs) and 62 800 deaths in the country, and 83% of the attributable burden was found in children less than 5 years old. Per capita DALYs increased along an east-west gradient, with the highest burden in inland provinces having the lowest income per capita. Conclusion Despite remarkable progress, China still needs to conduct infrastructural improvement projects targeting provinces that have experienced slower economic development. Improved monitoring, increased regulatory oversight and more government transparency are needed to better estimate the effects of microbiologically and chemically contaminated water and poor sanitation and hygiene on human health.


Wang Y.-Z.,Harbin Institute of Technology | Wang A.-J.,Harbin Institute of Technology | Wang A.-J.,CAS Research Center for Eco Environmental Sciences | Liu W.-Z.,CAS Research Center for Eco Environmental Sciences | Sun Q.,Harbin Institute of Technology
Bioresource Technology | Year: 2013

Azo dye is widely used in printing and dyeing process as one of refractory wastewaters for its high chroma, stable chemical property and toxicity for aquatic organism. Biocatalyzed electrolysis system (BES) is a new developed technology to degrade organic waste in bioanode and recover recalcitrant contaminants in cathode with effective decoloration. The ion exchange membrane (IEM) separate anode and cathode for biofilm formation protection. Azo removal efficiency was up to 60.8%, but decreased to 20.5% when IEM was removed. However, expensive ion exchange membrane (IEM) not suitable for further practical application, bioelectrochemical activity of bioanode is sensitive to the toxicity of azo dye. A gradient increase of azo dye concentration was used to acclimate anode biofilm to pollutant toxicity. The azo removal efficiency can be enhanced to 73.3% in 10. h reaction period after acclimation. The highest removal efficiency reached 83.7% and removal rates were increased to 8.37 from 3.04. g/h/L of dual-chamber. That indicated the feasibility for azo dye removal by single-chamber BES. The IEM cancellation not only decreased the internal resistance, but increased the current density and azo dye removal. © 2013 Elsevier Ltd.


Kong F.,Harbin Institute of Technology | Wang A.,Harbin Institute of Technology | Liang B.,Harbin Institute of Technology | Liu W.,CAS Research Center for Eco Environmental Sciences | Cheng H.,Harbin Institute of Technology
Bioresource Technology | Year: 2013

Bioelectrochemical system (BES) that removes recalcitrant pollutant out of wastewater is of special interest for practice. This study modified the configuration of BES to be a sleeve-type with compact structure. Azo dye (acid orange 7, AO7) in the outer cathode chamber performed a complete decolorization by electrons supplied from acetate oxidized with electricigens in the inner anode chamber. The AO7 decolorization efficiency (DEAO7) was enhanced to be higher than 98% from 0.14 to 2.00mM. Electrochemical impedance spectroscopy (EIS) analysis showed that the internal resistance of anode, cathode and the whole cell was 26.4, 38.3, and 64.6Ω, respectively, indicating that the modified configuration with large area and small distance between anode and cathode can result in a lower internal resistance and higher decolorization performance. This is the first study for azo dye decolorization using sleeve-type configuration with highly efficient decolorization by abiotic cathode BES. © 2013 Elsevier Ltd.


Wu L.,Shandong University | Zhang Y.,Shandong University | Zhang C.,Shandong University | Cui X.,Shandong University | And 8 more authors.
ACS Nano | Year: 2014

The induction of autophagy by nanoparticles causes nanotoxicity, but appropriate modulation of autophagy by nanoparticles may have therapeutic potential. Multiwalled carbon nanotubes (MWCNTs) interact with cell membranes and membrane-associated molecules before and after internalization. These interactions alter cellular signaling and impact major cell functions such as cell cycle, apoptosis, and autophagy. In this work, we demonstrated that MWCNT-cell interactions can be modulated by varying densely distributed surface ligands on MWCNTs. Using a fluorescent autophagy-reporting cell line, we evaluated the autophagy induction capability of 81 surface-modified MWCNTs. We identified strong and moderate autophagy-inducing MWCNTs as well as those that did not induce autophagy. Variation of the surface ligand structure of strong autophagy nanoinducers led to the induction of different autophagy-activating signaling pathways, presumably through their different interactions with cell surface receptors. © 2014 American Chemical Society.


Wang X.,CAS Research Center for Eco Environmental Sciences | Li Y.,CAS Research Center for Eco Environmental Sciences | Liu J.,CAS Research Center for Eco Environmental Sciences | Ren N.-Q.,Harbin Institute of Technology | Qu J.,CAS Research Center for Eco Environmental Sciences
Water Research | Year: 2016

Waste-derived acetic acid (HAc) is an attractive feedstock for microbe-mediated biofuel production. However, fermentative conversion of HAc from waste-activated sludge (WAS) has low yield because of the high concentration of proteins not readily utilizable by microorganisms without prior hydrolysis. We investigated a combined technology for HAc augmentation during sludge protein fermentation. The maximal HAc yield increased over two-fold, reaching 0.502 ± 0.021 g/g protein (0.36 ± 0.01 g COD/g COD, ~52% of the total volatile fatty acids) when synthetic sludge protein was heated at 120 °C for 30 min, treated at pH 12 for 24 h, and fermented at pH 9 for 72 h. Comprehensive analysis illustrated that the heat-alkaline pretreatment significantly induced protein fragmentation, simultaneously increasing the efficiency of protein biohydrolysis (from 35.5% to 85.9%) by inducing conformational changes indicative of protein unfolding. Consequently, the native α-helix content was decreased from 67.3% to 32.5% by conversion to an unordered shape, whose content increased from 27.5% to 45.5%; disulfide bonds were cleaved, whereas the main S-S stretching pattern was altered from gauche-gauche-gauche to gauche-gauche-trans, consequently causing increased protein susceptibility to proteolytic hydrolysis (76.3% vs. 47.0%). Economic analysis indicated that anaerobic fermentation with appropriate heat-alkaline pretreatment is a cost-effective approach for waste conversion to energy sources such as HAc. © 2015 Elsevier Ltd.


Di H.J.,Lincoln University at Christchurch | Cameron K.C.,Lincoln University at Christchurch | Sherlock R.R.,Lincoln University at Christchurch | Shen J.-P.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Journal of Soils and Sediments | Year: 2010

Purpose: Nitrous oxide (N2O) is a potent greenhouse gas and, in grazed grassland systems where animals graze outdoor pastures, most of the N2O is emitted from animal urine nitrogen (N) deposited during grazing. Recently, ammonia-oxidizing archaea (AOA) were found to be present in large numbers in soils as well in the ocean, suggesting a potentially important role for AOA, in addition to ammonia-oxidizing bacteria (AOB), in the nitrogen cycle. The relationship between N2O emissions and AOB and AOA populations is unknown. The objective of this study was to determine the quantitative relationship between N2O emissions and AOB and AOA populations in nitrogen-rich grassland soils. Materials and methods: We determined N2O emissions and the abundance and activity of AOB and AOA in four different soils as affected by the applications of animal urine N and dicyandiamide (DCD) as a nitrification inhibitor. Relationships were then determined between N2O emissions and the AOB and AOA populations. Results and discussion: Total N2O emissions from the urine N applied at 1,000 kg N ha-1 varied significantly in these soils, from 13.9 to 39.8 kg N2O-N ha-1. The DCD treatment reduced these N2O emissions to between 2.8 and 15.3 kg N2O-N ha-1. The average emission factor of the urine N (EF3) was 2.2% and this was decreased to 0.8%, representing a 64% reduction. Total N2O emissions were significantly related to the amoA gene copy numbers of the AOB population and to the amount of nitrate-N in the soil, but not related to the abundance of AOA. Conclusions: These results demonstrate that the N2O flux is mainly associated with the dynamics of the AOB population rather than the AOA in these nitrogen-rich grassland soils, and therefore, it is the AOB that should be the target of inhibition when mitigating N2O emissions using nitrification inhibitors. © 2010 Springer-Verlag.


Zhang Z.,CAS Research Center for Eco Environmental Sciences | Liu J.-F.,CAS Research Center for Eco Environmental Sciences | Shao B.,U.S. Center for Disease Control and Prevention | Jiang G.-B.,CAS Research Center for Eco Environmental Sciences
Environmental Science and Technology | Year: 2010

Using monoclonal antibodies labeled with Eu3+ chelates, time-resolved fluoroimmunoassay (TRFIA) methodsweredeveloped for the determination of trace sulfamethazine (SMZ), sulfamethoxazole (SMX), and sulfadiazine (SDZ) in environmental waters. Under the optimized conditions, the developed methods offered (i) low detection limits (9.8 ng/L SMZ, 6.1 ng/L SMX, and 5.4 ng/L SDZ, based on 90% inhibition) which were about 1 order of magnitude lower than that of the enzyme-linked immunosorbent assay (ELISA), (ii) high selectivity with no cross-reactivity (<0.05%) to similarly structured sulfonamides; (iii) high tolerance to variation of the sample pH (6.0-9.0) and salinity (0-100 mM), as well as the presence of humic acid (0-100 mg/L DOC) and heavy metals (0-1 mg/L concentration each of Cu2+, Cd2+, Hg2+, Pb2+, and As(V)) in the samples, and (iv) direct determination with low cost, high sample throughput, and low sample consumption (50-100 μL). The proposed TRFIA procedures were applied to determine sulfonamides in a variety of surface water and wastewater samples without sample pretreatment other than filtration. The satisfactory recoveries (64-127%) and reproducibilities (CV ) 0.2-16%) achieved, as well as the good agreement with those given by liquid chromatography-tandem mass spectroscopy and ELISA methods, demonstrated the applicability of the proposed TRFIA methods for routine screening/quantification of sulfonamides in environmental waters. © 2010 American Chemical Society.


Yu W.-Z.,CAS Research Center for Eco Environmental Sciences | Liu H.-J.,CAS Research Center for Eco Environmental Sciences | Liu T.,Harbin Institute of Technology | Liu R.-P.,CAS Research Center for Eco Environmental Sciences | Qu J.-H.,CAS Research Center for Eco Environmental Sciences
Desalination | Year: 2013

Coagulation in submerged ultrafiltration tank (sub-CUF) with continuous low aeration was compared with traditional coagulation by alum in flocculation system and subsequent ultrafiltration (CUF), for treating synthetic humic acid water. The transmembrane pressure (TMP) in sub-CUF was much lower comparing with the one in CUF. Humic acid was removed significantly by coagulation process in two membrane systems, but there was no difference of removal efficiency between these two membrane tanks. Active flocs formed in sub-CUF were significantly larger than those formed in CUF, and the frequency of small flocs was also lower than that in CUF. The coagulation process in jar test confirmed that continuous precipitate of alum can significantly increase the activity of flocs, causing dramatically higher growth ability of flocs. The fractal dimension of flocs formed in sub-CUF (2.53) was lower than that in CUF (2.65) as the continuous new coagulant activated the surface of flocs and increased the branches of flocs, which may induce lower density of cake layer. The image of scanning electron microscope (SEM) further confirmed that the density of cake layer on the sub-CUF membrane surface was lower than that by CUF. Therefore, the characteristic of flocs and cake layer, changed by continuous freshly formed hydroxide precipitate of alum by re-activating the inactive surface sites of aged flocs, caused lower increase of TMP development. © 2012 Elsevier B.V.


Wang X.,CAS Research Center for Eco Environmental Sciences | Liu J.,CAS Research Center for Eco Environmental Sciences | Ren N.-Q.,Harbin Institute of Technology | Duan Z.,AECOM Technology Corporation
Bioresource Technology | Year: 2012

Stringent new legislation for wastewater treatment plants (WWTPs) is currently motivating innovation and optimization of wastewater treatment technologies. Evaluating the environmental performance of a wastewater treatment system is a necessary precursor before proposing implementation of WWTPs designed to address the global requirements for reduced resource use, energy consumption and environmental emissions. However, developing overly-sophisticated treatment methods may lead to negative environmental effects. This study was conducted to employ a process modeling approach from a life cycle perspective to construct and evaluate six anaerobic/anoxic/oxic wastewater treatment systems that include a water line, sludge line and bioenergy recovery system and was designed to meet different treatment standards in China. The results revealed that improved treatments optimized for local receiving watercourses can be realized at the cost of higher resource consumption and greenhouse gas emissions. Optimal Scenarios were also identified from different positive perspectives. © 2012 Elsevier Ltd.


Peng C.,CAS Research Center for Eco Environmental Sciences | Chen W.,CAS Research Center for Eco Environmental Sciences | Liao X.,Hunan Agricultural University | Wang M.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Environmental Pollution | Year: 2011

We studied the source, concentration, spatial distribution and health risk of 16 polycyclic aromatic hydrocarbons (PAHs) in urban soils of Beijing. The total mass concentration of 16 PAHs ranged from 93 to 13 141 μg kg -1 with a mean of 1228 μg kg-1. The contour map of soil PAH concentrations showed that the industrial zone, the historical Hutong district and the university district of Beijing have significantly higher concentrations than those in remainder of the city. The results of sources identification suggested that the primary sources of PAHs were vehicle exhaust and coal combustion and the secondary source was the atmospheric deposition of long-range transported PAHs. The incremental lifetime cancer risks (ILCRs) of exposing to PAHs in the urban soils of Beijing for adult were 1.77 × 10-6 and 2.48 × 10-5, respectively under normal and extreme conditions. For child, they were 8.87 × 10-7 and 6.72 × 10-6, respectively under normal and extreme conditions. © 2010 Elsevier Ltd. All rights reserved.


Okkenhaug G.,Norwegian University of Life Sciences | Okkenhaug G.,Norwegian Geotechnical Institute | Zhu Y.-G.,CAS Research Center for Eco Environmental Sciences | Luo L.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Environmental Pollution | Year: 2011

Here, we present one of the first studies investigating the mobility, solubility and the speciation-dependent in-situ bioaccumulation of antimony (Sb) in an active Sb mining area (Xikuangshan, China). Total Sb concentrations in soils are high (527-11,798 mg kg -1), and all soils, including those taken from a paddy field and a vegetable garden, show a high bioavailable Sb fraction (6.3-748 mg kg -1), dominated by Sb(V). Elevated concentrations in native plant species (109-4029 mg kg -1) underpin this. Both chemical equilibrium studies and XANES data suggest the presence of Ca[Sb(OH) 6] 2, controlling Sb solubility. A very close relationship was found between the citric acid extractable Sb in plants and water or sulfate extractable Sb in soil, indicating that citric acid extractable Sb content in plants may be a better predictor for bioavailable Sb in soil than total acid digestible Sb plant content. © 2010 Published by Elsevier Ltd.


Li Y.,CAS Research Center for Eco Environmental Sciences | Geng D.,CAS Research Center for Eco Environmental Sciences | Geng D.,China University of Geosciences | Liu F.,National Marine Environmental Forecasting Center | And 4 more authors.
Atmospheric Environment | Year: 2012

Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ∑ indicator PCBs and ∑ 14 PBDEs ranged from 1.66 to 6.50 pg m -3 and from 0.67 to 2.98 pg m -3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m -3 (average 15.2 pg m -3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere. © 2012 Elsevier Ltd.


Du B.,CAS Research Center for Eco Environmental Sciences | Du B.,Chinese Research Academy of Environmental Sciences | Zhou C.,Chinese Research Academy of Environmental Sciences | Dan Z.,Chinese Research Academy of Environmental Sciences | And 2 more authors.
Construction and Building Materials | Year: 2014

Electrolytic manganese solid waste (EMSW) is a sort of hydrometallurgical process residue from sulfuric acid leaching for rhodochrosite. The objective of this study was to investigate the feasibility of producing steam-autoclaved bricks with EMSW, and to determine the most appropriate preparation conditions. We tested the compressive strength (CS), dry shrinkage (DS) and frost resistance (FR), using microstructure change analysis combined with component reactions. The crystalline components of raw materials and bricks were examined by X-ray diffraction. Other properties of the brick, including leaching toxicity and radioactivity, were also measured to examine the environmental safety of EMSW steam-autoclaved bricks. The results show that the most appropriate conditions were: EMSW content of 30-40% by mass ratio, cement content of 10.5-12%, formation pressure of 15-20 MPa, W/C ratio of 0.4 and steam pressure of 1.2-1.5 MPa. Under those conditions, the compressive strength can be higher than 15 MPa, dry shrinkage lower than 0.11%, and compressive strength loss and weight loss lower than 10% and 2%, respectively. The compressive strength, leaching toxicity and radioactivity of the brick manufactured under the aforementioned conditions met the standards of GB 11945-1999 MU 15, GB 5085.3-2007 and GB 6566-2010, respectively. The compressive strength mechanism was formed by C-S-H gel and ettringite detected in the brick samples. Dry shrinkage was caused mainly by the removal of gaseous components and the shrinkage of cementitious materials. Frost resistance was influenced mainly by an increase in hydraulic pressure within the pore spaces. © 2013 Elsevier Ltd. All rights reserved.


Zhao X.,CAS Research Center for Eco Environmental Sciences | Zhao X.,Chinese Research Academy of Environmental Sciences | Wang J.,CAS Research Center for Eco Environmental Sciences | Wu F.,Chinese Research Academy of Environmental Sciences | And 4 more authors.
Journal of Hazardous Materials | Year: 2010

A novel magnetic nanosized adsorbent using hydrous aluminum oxide embedded with Fe3O4 nanoparticle (Fe3O4@Al(OH)3 NPs), was prepared and applied to remove excessive fluoride from aqueous solution. This adsorbent combines the advantages of magnetic nanoparticle and hydrous aluminum oxide floc with magnetic separability and high affinity toward fluoride, which provides distinctive merits including easy preparation, high adsorption capacity, easy isolation from sample solutions by the application of an external magnetic field. The adsorption capacity calculated by Langmuir equation was 88.48 mg g-1 at pH 6.5. Main factors affecting the removal of fluoride, such as solution pH, temperature, adsorption time, initial fluoride concentration and co-existing anions were investigated. The adsorption capacity increased with temperature and the kinetics followed a pseudo-second-order rate equation. The enthalpy change (ΔH0) and entropy change (ΔS0) was 6.836 kJ mol-1 and 41.65 J mol-1 K-1, which substantiates the endothermic and spontaneous nature of the fluoride adsorption process. Furthermore, the residual concentration of fluoride using Fe3O4@Al(OH)3 NPs as adsorbent could reach 0.3 mg L-1 with an initial concentration of 20 mg L-1, which met the standard of World Health Organization (WHO) norms for drinking water quality. All of the results suggested that the Fe3O4@Al(OH)3 NPs with strong and specific affinity to fluoride could be excellent adsorbents for fluoride contaminated water treatment. © 2009 Elsevier B.V. All rights reserved.


Zhang Y.,CAS Research Center for Eco Environmental Sciences | Liu J.,CAS Research Center for Eco Environmental Sciences | Mu Y.,CAS Research Center for Eco Environmental Sciences | Pei S.,Beijing Forestry University | And 2 more authors.
Atmospheric Environment | Year: 2011

The exchange fluxes of nitrous oxide (N2O), nitrogen oxides (NOx) and ammonia (NH3) from a maize field with three different treatments were simultaneously measured using static and dynamic chambers in the North China Plain (NCP) from June 28 to October 11, 2009. The three treatments included control plot (CK, without crop, fertilization and irrigation), fertilizer N plot (NP) and wheat straw returning plus fertilizer N plot (SN). N-fertilizer application greatly stimulated the emissions of N2O, NOx and NH3, with durations of about 10 days for N2O and NO, and about 7 days for NH3. Fertilizer loss rates were 1.08% (NP plot) and 1.20% (SN plot) as N2O-N, were 1.93% (NP plot) and 0.76% (SN plot) as NO-N, and were 5.24% (NP plot) and 3.03% (SN plot) as NH3-N. In comparison with the NP plot, the significant low fertilizer loss rates as NO-N and NH3-N from the SN plot indicated that the wheat straw returning to the field could reduce NOx and NH3 emissions. The molar ratio of NO/N2O was greater than unity for most data during the pulse emission periods induced by fertilization, and thus, nitrification was the dominant process for N2O and NO emissions during these periods. Considering the significant amount (>80%) of N2O and NOx emissions occurred during the pulse emission periods, the emissions of NOx and N2O from the investigated field were mainly ascribed to nitrification process. © 2010 Elsevier Ltd.


Qu D.,Beijing Forestry University | Qiang Z.,CAS Research Center for Eco Environmental Sciences | Xiao S.,Chinese Research Academy of Environmental Sciences | Liu Q.,Beijing Forestry University | And 2 more authors.
Separation and Purification Technology | Year: 2014

A novel submerged photocatalytic membrane distillation reactor (SPMDR) was developed and microwave electrodeless lamps were applied as the source light. Reactive Black 5 was used as a model dye with an initial concentration of 400 mg/L. The effects of TiO2 dose and feed temperature on the photodegradation efficiency and permeate flux were first investigated. The highest degradation rate was observed at 2.0 g/L TiO2 and 65 C. The permeate flux decreased by 15.8% when the TiO2 dose increased from 0.5 to 6.0 g/L. The permeate flux of the SPMDR in the presence of 2.0 g/L TiO2 was higher than the pure water flux using conventional heating, which confirms the enhancement of microwave irradiation to the membrane distillation mass transfer. The SPMDR achieved a high color (100%) and TOC (80.1%) removal efficiency after 300 min reaction. The byproducts identified in the feed included aliphatic acids (formic, acetic and maleic) and inorganic ions (SO42-, NH4+ and NO3-). The SPMDR produced high quality water because dye, TiO2 and inorganic ions were completely retained in the feed side. Formic and acetic acids were detected in the permeate side with amounts of 0.08 and 0.25 mg (i.e., 1.83 and 5.29 mg/L), respectively. Scanning electron microscope (SEM) images showed that a loose TiO2 cake layer was formed on the membrane surface, which decreased the membrane porosity and contact angle to some extent. However, the module efficiency, porosity and contact angle could be largely recovered after 30 min of washing with distilled water. © 2013 Elsevier B.V. All rights reserved.


Wang F.-H.,CAS Research Center for Eco Environmental Sciences | Qiao M.,CAS Research Center for Eco Environmental Sciences | Lv Z.-E.,Xinjiang University | Guo G.-X.,CAS Research Center for Eco Environmental Sciences | And 4 more authors.
Environmental Pollution | Year: 2014

The abundance and distribution of antibiotics and antibiotic resistance genes (ARGs) in soils from six parks using reclaimed water in Beijing, China, were characterized. Three classes of commonly used antibiotics (tetracycles, quinolones, and sulfonamides) were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The highest concentrations of tetracyclines and quinolones were 145.2 μg kg-1 and 79.2 μg kg-1, respectively. Detected tetG, tetW, sulI, and sulII genes were quantified by quantitative PCR. ARGs exhibited various abundances for different park soils. The integrase gene (intI1) as an indicator of horizontal gene transfer potential was also detected in high abundance, and had significant positive correlation with tetG, sulI, and sulII genes, suggesting that intI1 may be involved in ARGs dissemination. Both sulII and intI1 clones had high homology with some classes of pathogenic bacteria, such as Klebsiella oxytoca, Acinetobacter baumannii, Shigella flexneri, which could trigger potential public health concern. © 2013 Elsevier Ltd. All rights reserved.


Sun G.-X.,CAS Research Center for Eco Environmental Sciences | Van De Wiele T.,Ghent University | Alava P.,Ghent University | Tack F.,Ghent University | Du Laing G.,Ghent University
Environmental Pollution | Year: 2012

Rice, used as staple food for half of the world population, can easily accumulate arsenic (As) into its grain, which often leads to As contamination. The health risk induced by presence of As in food depends on its release from the food matrix, i.e., its bioaccessibility. Using an in vitro gastrointestinal simulator, we incubated two types of cooked rice (total As: 0.389 and 0.314 mg/kg). Arsenic bioaccessibility and speciation changes were determined upon gastrointestinal digestion. Washing with deionized water and cooking did not result in changes of As speciation in the rice although the arsenic content dropped by 7.1-20.6%. Arsenic bioaccessibility of the cooked rice in the small intestine ranged between 38 and 57%. Bioaccessibility slightly increased during digestion in the simulated small intestine and decreased with time in the simulated colon. Significant speciation changes were noted in the simulated colon, with trivalent monomethylarsonate (MMA III) becoming an important species. © 2011 Elsevier Ltd. All rights reserved.


Zheng X.,CAS Research Center for Eco Environmental Sciences | Zheng X.,China National Environmental Monitoring Center | Liu X.,Chinese Research Academy of Environmental Sciences | Jiang G.,CAS Research Center for Eco Environmental Sciences | And 4 more authors.
Environmental Pollution | Year: 2012

Surface soils were collected in Balang Mountain to explore the environmental process of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) during air transport. The average concentrations of ∑ 25PCBs and ∑ 13PBDEs in soils were 163 pg/g and 26 pg/g, respectively. The significant correlations between the concentrations of pollutants and total organic carbon (TOC) indicated the importance of TOC in accumulation potential of POPs. The slopes from fitted curves of PCBs were highly related with logK oa, demonstrating that TOC dominates the soil-air exchange of PCBs. The TOC-normalized concentrations of contaminants in samples from below-treeline were higher than those from alpine meadow, probably due to the forest filter effect. The increasing trends of the concentrations with altitude from the alpine meadow samples, could be attributed to the mountain cold-trapping effect. And the weak cold-trapping effect of POPs might be due to the less precipitation in 2008 when comparing with those in 2006. © 2011 Elsevier Ltd. All rights reserved.


Lu C.,Beijing University of Chemical Technology | Li Q.,Beijing University of Chemical Technology | Chen S.,Beijing University of Chemical Technology | Zhao L.,CAS Research Center for Eco Environmental Sciences | Zheng Z.,Chinese Research Academy of Environmental Sciences
Talanta | Year: 2011

In this study, gold nanorods were firstly found to exhibit a tremendously higher catalytic activity towards luminol chemiluminescence (CL) than spherical gold nanoparticles. More importantly, ultra-trace aminothiols can cause a great CL decrease in the gold nanorod-catalyzed luminol system by the formation of Au-S covalent bonds on the ends of gold nanorods. Aminothiols can occupy the active sites of gold nanorods, and further interrupt the generation of the active oxygen intermediates. Other biomolecules including 19 standard amino acids, alcohols, organic acids and saccharides have no effect on gold nanorod-catalyzed luminol CL signals. Moreover, in order to evaluate the applicability and reliability of the proposed method, it was applied to the determination of glutathione in the cell extracts of Saccharomyces cerevisiae. Good agreements were obtained for the determination of glutathione in the cell extracts of S. cerevisiae between the present approach and a standard Alloxan method. The recoveries of glutathione were found to fall in the range between 96 and 105%. The calibration curve for glutathione was found to be linear from 0.05 to 100 nM, and the detection limit (S/N = 3) was 0.01 nM. The relative standard deviation (RSD) for five repeated measurements of 5.0 nM glutathione was 2.1%. © 2011 Elsevier B.V. All rights reserved.


Zhou A.,Harbin Institute of Technology | Guo Z.,Harbin Institute of Technology | Yang C.,Harbin Institute of Technology | Kong F.,Harbin Institute of Technology | And 3 more authors.
Journal of Biotechnology | Year: 2013

Volatile fatty acids (VFAs) are the most suitable and biodegradable carbon substrates for many bioprocesses. This study explored a new approach to improve the VFAs production from anaerobic co-digesting waste activated sludge (WAS) with corn straw (CS). The effect of feedstock proportion on the acidification efficiency was investigated. The maximum VFAs yield (corresponding fermentation time) was substantially increased 69% (96h), 45% (72h), 13% (120h) and 12% (120h) with 50%, 35%, 25% and 20% CS proportion of feedstock, respectively. HAc (acetic acid) was consistently the most abundant, followed by HPr (propionic acid) and n-HBu (butyric acid) in the co-digesting tests. The increase of CS in feedstock led to more production of HAc and HPr. Moreover, the consumption of protein and carbohydrate were also improved remarkably from 2955 and 249mg COD/L (individual WAS fermentation) to 6575 and 815mg COD/L (50%WAS:50%CS co-digestion) from 120 onward, respectively. The highest contribution of CS to additional VFAs production was1113mg VFAs (as COD)/g CS/L in the 65%WAS:35%CS co-digesting test. Our study indicated a valuable method to improve VFAs production from anaerobic co-digesting WAS and CS. © 2013.


Zhang S.-Y.,CAS Research Center for Eco Environmental Sciences | Zhang S.-Y.,University of Chinese Academy of Sciences | Sun G.-X.,CAS Research Center for Eco Environmental Sciences | Yin X.-X.,Chinese Research Academy of Environmental Sciences | And 3 more authors.
Chemosphere | Year: 2013

Ostreococcus tauri is a marine green microalga, recognized as a model organism of the marine phytoplankton assemblage and widely distributed from coastal to oligotrophic waters. This study showed it could tolerate both arsenite and arsenate concentrations of up to 100. μM, and cellular As concentration increased significantly (P<. 0.01) with increasing concentration of As(V) in the medium (0-50. μM). It was revealed that As biotransformations were mediated by algal cells. Volatilized As was detected and the ability of As biovolatilization by O. tauri was demonstrated. The reduction of As(V) to As(III) might be the limiting step for As methylation and volatilization from seawater since the treatment with As(III) yielded five times more volatile As as compared to that with As(V). Arsenic biogeochemical cycle in the marine environment might play an important role based on the huge surface area of ocean (71%) and the massive number of marine phytoplankton. © 2013 Elsevier Ltd.


Kong F.,Harbin Institute of Technology | Wang A.,Harbin Institute of Technology | Wang A.,CAS Research Center for Eco Environmental Sciences | Ren H.-Y.,Harbin Institute of Technology
Bioresource Technology | Year: 2014

This modular design could be scalable with successive modules for BES scale-up. This study developed and optimized a modular biocathode materials design in bioelectrochemical system (BES) using composite metal and carbon-based materials. The 4-chlorophenol (4-CP) dechlorination could be improved with such composite materials. Results showed that stainless steel basket (SSB) filled with graphite granules (GG) and carbon brush (CB) (SSB/GG/CB) was optimum for dechlorination, followed by SSB/CB and SSB/GG, with rate constant k of 0.0418±0.0002, 0.0374±0.0004, and 0.0239±0.0002h-1, respectively. Electrochemical impedance spectroscopy (EIS) demonstrated that the composite materials with metal can benefit the electron transfer and decrease the charge transfer resistance to be 80.4Ω in BES-SSB/GG/CB, much lower than that in BES-SSB (1674.3Ω), BES-GG (387.3Ω), and BES-CB (193.8Ω). This modular cathode design would be scalable with successive modules for BES scale-up, and may offer useful information to guide the selection and design of BES materials towards dechlorination improvement in wastewater treatment. © 2014 Elsevier Ltd.


Yin R.,CAS Research Center for Eco Environmental Sciences | Mo J.,CAS Research Center for Eco Environmental Sciences | Lu M.,Agilent Technologies | Wang H.,CAS Research Center for Eco Environmental Sciences
Analytical Chemistry | Year: 2015

The sixth DNA base 5-hydroxymethylcytosine (5hmC) is the major oxidation product of the epigenetic modification 5-methylcytosine (5mC), mediating DNA demethylation in mammals. Reduced 5hmC levels are found to be linked with various tumors and neurological diseases; therefore, 5hmC is an emerging biomarker for disease diagnosis, treatment, and prognosis. Due to its advantages of being sterile, easily accessible in large volumes, and noninvasive to patients, urine is a favored diagnostic biofluid for 5hmC analysis. Here we developed an accurate, sensitive, and specific assay for quantification of 5mC, 5hmC, and other DNA demethylation intermediates in human urine. The urinary samples were desalted and enriched using off-line solid-phase extraction, followed by stable isotope dilution HPLC-MS/MS analysis for 5hmC and 5mC. By the use of ammonium bicarbonate (NH4HCO3) as an additive to the mobile phase, we improved the online-coupled MS/MS detection of 5mC, 5hmC, and 5-formylcytosine (5fC) by 1.8-14.3 times. The recovery of the method is approximately 100% for 5hmC, and 70-90% for 5mC. The relative standard deviation (RSD) of the interday precision is about 2.9-10.6%, and that of the intraday precision is about 1.4-7.7%. By the analysis of 13 volunteers using the developed method, we for the first time demonstrate the presence of 5hmC in human urine. Unexpectedly, we observed that the level of 5hmC (22.6 ± 13.7 nmol/L) is comparable to that of its precursor 5mC (52.4 ± 50.2 nmol/L) in human urine. Since the abundance of 5hmC (as a rare DNA base) is 1 or 2 orders of magnitude lower than 5mC in genomic DNA, our finding probably implicates a much higher turnover of 5hmC than 5mC in mammalian genomic DNA and underscores the importance of DNA demethylation in daily life. © 2014 American Chemical Society.


Guo F.,CAS Research Center for Eco Environmental Sciences | Liu Q.,CAS Research Center for Eco Environmental Sciences | Shi J.-B.,CAS Research Center for Eco Environmental Sciences | Wei F.-S.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Talanta | Year: 2014

A novel method for determining eight chlorophenols (CPs) by large volume injection online turbulent flow solid-phase extraction high performance liquid chromatography in urine samples was developed. An aliquot of 1.0 mL urine sample could be analyzed directly after centrifugation. The analytes were preconcentrated online on a Turboflow C18-P SPE column, eluted in back-flush mode, and then separated on an Acclaim PA2 analytical column. Major parameters such as SPE column type, sample loading flow rate and elution time were optimized in detail. Eight CPs from monochlorophenol to pentacholophenol were measured by multiple-wavelength UV detection at four different wavelengths. The limits of detection (LODs) were between 0.5 and 2 ng/mL. The linearity range was from the limit of quantification to 1000 ng/mL for each compound, with the coefficients of determination (r2) ranging from 0.9990 to 0.9996. The reproducibility of intraday and interday relative standard deviations (RSDs) ranged from 0.6% to 4.5% (n=5). The method was successfully applied to analyze eight CPs in urine samples. Good recoveries, ranging from 76.3% to 122.9%, were obtained. This simple, sensitive and accurate method provides an alternative way to rapidly analyze and monitor CPs in urine samples, especially for matters of occupational exposure. © 2013 Elsevier B.V.


Kong F.,Harbin Institute of Technology | Wang A.,Harbin Institute of Technology | Cheng H.,CAS Research Center for Eco Environmental Sciences | Liang B.,Harbin Institute of Technology
Bioresource Technology | Year: 2014

In this study, BES with bioanode and biocathode was applied to decolorize an azo dye Congo red (CR). Results showed that the Congo red decolorization efficiency (CR-DE) within 23. h in a combined bioanode-biocathode single chamber BES was 98.3. ±. 1.3%, significantly higher than that of mixed solution in a dual chamber BES (67.2. ±. 3.5%) (. P<. 0.005). Various electrodes deployments (horizontal, vertical and surrounding) in the combined bioanode-biocathode BES were further compared based on the decolorization performance and electrochemical characterization. Results indicated that CR-DE within 11. h improved from 87.4. ±. 1.3% to 97.5. ±. 2.3%, meanwhile the internal resistance decreased from 236.6 to 42.2. Ω as modifying the horizontal deployment to be a surrounding deployment. It proved that the combination of bioanode and biocathode with suitable electrodes deployment could accelerate the decolorization of azo dye Congo red, which would be great potential for the application of bioelectrochemical technology in azo dye wastewater treatment. © 2013 Elsevier Ltd.


Zhang H.,Beijing University of Chemical Technology | Zhang L.,Beijing University of Chemical Technology | Lu C.,Beijing University of Chemical Technology | Zhao L.,CAS Research Center for Eco Environmental Sciences | Zheng Z.,Chinese Research Academy of Environmental Sciences
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

It was found that CdTe semiconductor nanocrystals (NCs) can induce a great sensitized effect on chemiluminescence (CL) emission from peroxynitrous acid (ONOOH)-Na 2CO 3 system. CL spectra, fluorescence (FL) spectra, and the quenching effect of reactive oxygen species were used to investigate the CL reaction mechanism. The CL intensity was proportional to the concentration of nitrite in the range from 0.05 to 50 μM. The detection limit (S/N = 3) was 0.024 μM and the relative standard deviation (RSD) for five repeated measurements of 0.5 μM nitrite was 4.2%. This method has been successfully applied to determine nitrite in well water samples with recoveries of 94.0-100.5%. This was the first work for direct (not inhibition effect) determination of analytes using semiconductor NCs-based CL sensor. © 2011 Elsevier B.V. All rights reserved.


He C.,Chinese Institute of Urban Environment | He C.,Xi'an Jiaotong University | Yu Y.,Chinese Institute of Urban Environment | Yue L.,CAS Research Center for Eco Environmental Sciences | And 6 more authors.
Applied Catalysis B: Environmental | Year: 2014

A series of CuCeOx binary oxide catalysts with high specific surface area and mesoporous structure were synthesized by a facile self-precipitation approach. Toluene and propanal were adopted as the probe pollutants to evaluate their catalytic performance. The techniques such as XRD, N2 adsorption/desorption, FE-SEM, TEM, H2-TPR, XPS, Raman, DRUV-vis, and XANES, were employed for catalyst characterization. It is shown that plenty of Cu2+ ions in mesoporous CuCeOx oxides are incorporated into CeO2 lattice in the form of CuxCe1-xO2-δ solid solution, which produces large amounts of oxygen vacancies in the interface of CuOx and CeO2 oxides. Meanwhile, the Cu2+-O2--Ce4+ connection in the solid solution can act as a bridge for oxygen transfer between Cu and Ce, and enhance the reducibility of both components. The activity of mesoporous CuCeOx catalysts exhibits a volcano-type behavior with the increase of the Cu content, and the sample with Cu/Ce atomic ratio of 3/7 exhibits the highest catalytic efficiency. At GHSV of 36,000h-1, the temperatures for 90% toluene and propanal conversion over Cu0.3Ce0.7Ox sample are 212 and 192°C, respectively, which are much lower than the catalysts synthesized via the incipient impregnation and thermal combustion methods. The co-combustion result demonstrates that propanal oxidation can be remarkably suppressed by the introduction of toluene due to the stronger surface affinity of toluene molecules. It can be concluded that both the higher surface oxygen adspeices concentration and better low-temperature reducibility were responsible for the superior activity of mesoporous CuCeOx catalysts. © 2013 Elsevier B.V.


Dai Y.,CAS Research Center for Eco Environmental Sciences | Dai Y.,University of Chinese Academy of Sciences | Di H.J.,Lincoln University at Christchurch | Cameron K.C.,Lincoln University at Christchurch | He J.-Z.,CAS Research Center for Eco Environmental Sciences
Science of the Total Environment | Year: 2013

Ammonia oxidizers, including ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) are important drivers of a key step of the nitrogen cycle - nitrification, which affects the production of the potent greenhouse gas, nitrous oxide (N2O). A field experiment was conducted to determine the effect of nitrogen application rates and the nitrification inhibitor dicyandiamide (DCD) on the abundance of AOB and AOA and on N2O emissions in a grazed pasture soil. Nitrogen (N) was applied at four different rates, with urea applied at 50 and 100kgNha-1 and animal urine at 300 and 600kgNha-1. DCD was applied to some of the N treatments at 10kgha-1. The results showed that the AOB amoA gene copy numbers were greater than those of AOA. The highest ratio of the AOB to AOA amoA gene copy numbers was 106.6 which occurred in the urine-N 600 treatment. The AOB amoA gene copy numbers increased with increasing nitrogen application rates. DCD had a significant impact in reducing the AOB amoA gene copy numbers especially in the high nitrogen application rates. N2O emissions increased with the N application rates. DCD had the most significant effect in reducing the daily and total N2O emissions in the highest nitrogen application rate. The greatest reduction of total N2O emissions by DCD was 69% in the urine-N 600 treatment. The reduction in the N2O emission factor by DCD ranged from 58% to 83%. The N2O flux and NO3 --N concentrations were significantly correlated to the growth of AOB, rather than AOA. This study confirms the importance of AOB in nitrification and the effect of DCD in inhibiting AOB growth and in decreasing N2O emissions in grazed pasture soils under field conditions. © 2012 Elsevier B.V.


Kaiser D.,Leibniz Center for Tropical Marine Ecology | Unger D.,Leibniz Center for Tropical Marine Ecology | Qiu G.,Guangxi Mangrove Research Center | Qiu G.,CAS Research Center for Eco Environmental Sciences
Continental Shelf Research | Year: 2014

Estuarine particle fluxes are an integral part of land-ocean-connectivity and influence coastal environmental conditions. In areas with strong anthropogenic impact they may contribute to coastal eutrophication. To investigate the particulate biogeochemistry of a human affected estuary, we sampled suspended, sedimentary and plant particulate matter along the land-ocean continuum from Nanliu River to Lianzhou Bay in southern China. Riverine particle fluxes exceed inputs from land based pond aquaculture. Elemental (C/N) and isotopic composition of particulate organic carbon (δ13C) and total nitrogen (δ15N) showed that suspended and sedimentary organic matter (OM) mainly derive from freshwater and marine phytoplankton, with minor contributions from terrestrial and aquaculture derived particles. Amino acid composition indicates subseasonal variability of production and freshness of phytoplankton OM. Strongest compositional changes of suspended particles are associated with storm-related extreme precipitation events, which introduce soil derived OM. High concentrations of chlorophyll a reflect eutrophic conditions in riverine and coastal waters. Human impact results in high δ15N signals in suspended, sedimentary and plant particulate matter. Using these in a comparison with two little affected sites shows that anthropogenic influence disperses from the Nanliu River to remote estuaries and mangrove areas. Our results suggest that autochthonous production binds anthropogenic nutrients in particles that are transported along the coast. © 2014 Elsevier Ltd.


Feng Z.,CAS Research Center for Eco Environmental Sciences | Wang S.,Beijing University of Chemical Technology | Szantoi Z.,University of Florida | Chen S.,CAS Research Center for Eco Environmental Sciences | Wang X.,CAS Research Center for Eco Environmental Sciences
Environmental Pollution | Year: 2010

A meta-analysis was conducted to quantitatively assess the effects of ethylenediurea (EDU) on ozone (O3) injury, growth, physiology and productivity of plants grown in ambient air conditions. Results indicated that EDU significantly reduced O3-caused visible injury by 76%, and increased photosynthetic rate by 8%, above-ground biomass by 7% and crop yield by 15% in comparison with non-EDU treated plants, suggesting that ozone reduces growth and yield under current ambient conditions. EDU significantly ameliorated the biomass and yield of crops and grasses, but had no significant effect on tree growth with an exception of stem diameter. EDU applied as a soil drench at a concentration of 200-400 mg/L has the highest positive effect on crops grown in the field. Long-term research on full-grown tree species is needed. In conclusion, EDU is a powerful tool for assessing effects of ambient [O 3] on vegetation. © 2010 Elsevier Ltd. All rights reserved.


Hu H.-W.,CAS Research Center for Eco Environmental Sciences | Hu H.-W.,University of Chinese Academy of Sciences | Zhang L.-M.,CAS Research Center for Eco Environmental Sciences | Dai Y.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Journal of Soils and Sediments | Year: 2013

Purpose: Ammonia-oxidizing archaea (AOA) and bacteria (AOB) are ubiquitous and important for nitrogen transformations in terrestrial ecosystems. However, the distribution patterns of these microorganisms as affected by the terrestrial environments across a large geographical scale are not well understood. This study was designed to gain insights into the ecological characteristics of AOA and AOB in 65 soils, collected from a wide range of soil and ecosystem types. Materials and methods: Barcoded pyrosequencing in combination with quantitative PCR was employed to characterize the relative abundance, diversity, and community composition of archaeal 16S rRNA gene, and AOA and AOB amoA genes in 65 soil samples. Results and discussion: The operational taxonomic unit richness and Shannon diversity of Thaumarchaeota, AOA, and AOB were highly variable among different soils, but their variations were best explained by soil pH. Soil pH was strongly correlated with the overall community composition of ammonia oxidizers, as measured by the pairwise Bray-Curtis dissimilarity across all sites. These findings were further corroborated by the evident pH-dependent distribution patterns of four thaumarchaeal groups (I.1a-associated, I.1b, I.1c, and I.1c-associated) and four AOB clusters (2, 3a.1, 10, and 12). The ratios of AOA to AOB amoA gene copy numbers significantly decreased with increasing pH, suggesting a competitive advantage of AOA over AOB in acidic soils. Conclusions: These results suggest that the distribution of ammonia oxidizers across large-scale biogeographical settings can be largely predicted along the soil pH gradient, thus providing important indications for the ecological characteristics of AOA and AOB in different soils. © 2013 Springer-Verlag Berlin Heidelberg.


Yin R.,CAS Research Center for Eco Environmental Sciences | Liu S.,CAS Research Center for Eco Environmental Sciences | Zhao C.,CAS Research Center for Eco Environmental Sciences | Lu M.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Analytical Chemistry | Year: 2013

Acrolein (Acr), a ubiquitous environmental pollutant, can react directly with genomic DNA to form mutagenic adducts without undergoing metabolic activation. To sensitively and accurately quantify Acr-DNA adducts (including structural isomers and stereoisomers) in human leukocytes, we developed an enhanced stable isotope dilution ultrahigh performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) method using ammonium bicarbonate (NH4HCO3), which is thermally unstable and degrades readily to carbon dioxide and ammonia in heated gas phase. Interestingly, ammonium bicarbonate (as an additive to the mobile phase) not only improves the protonation of AcrdG adducts but also suppresses the formation of MS signal-deteriorating metal-AcrdG complexes during electrospray ionization, leading to the enhancement of their MS detection by 2.3-8.7 times. In contrast, routinely used ammonium salts (ammonium acetate and ammonium formate) and formic acid do not show similar enhancement. The developed method is potentially useful for enhancing ESI-MS detection of other modified 2′- deoxyribonucleosides that have difficulty in protonation and may form excess metal complexes during electrospray ionization. The limits of detection (LODs, S/N = 3) are estimated to be about 40-80 amol. By the use of the developed method, we found that the Acr adducts of three nucleotides (dG, dA, and dC) can be detected in human leukocytes. In addition to the known γ-AcrdG, α-AcrdA is also identified as an Acr-adduct of high abundance (2.5-20 adducts per108 nts). © 2013 American Chemical Society.


Ouyang Z.,CAS Research Center for Eco Environmental Sciences | Zheng H.,CAS Research Center for Eco Environmental Sciences | Yue P.,Chinese Research Academy of Environmental Sciences
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

Ecological compensation institution plays a key role in promoting ecological protection and coordinating regional development. However, how to establishing effective and operational ecological compensation framework is still a great challenge. We summarized the ecological compensation practices in China and analyzed their problem, including lack of systematic institution design, deficient participation of stakeholders, lacking for scientific identification of ecological compensation scope, lower ecological compensation standards and absent supervision mechanism. Finally, the following strategies for ecological compensation institution establishment were put forward: fundamental principle for establishing ecological compensation institution, scientific definition of compensatory scope, identification of the compensatory carrier and object, building scientific method for compensatory standard accounting, and corresponding policy measures.


Shen J.-P.,CAS Research Center for Eco Environmental Sciences | Zhang L.-M.,CAS Research Center for Eco Environmental Sciences | Di H.J.,Lincoln University at Christchurch | He J.-Z.,CAS Research Center for Eco Environmental Sciences
Frontiers in Microbiology | Year: 2012

Ammonia (NH3) oxidation, the first and rate-limiting step of nitrification, is a key step in the global Nitrogen (N) cycle. Major advances have been made in recent years in our knowledge and understanding of the microbial communities involved in ammonia oxidation in a wide range of habitats, including Chinese agricultural soils. In this mini-review, we focus our attention on the distribution and community diversity of ammonia-oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) in Chinese soils with variable soil properties and soil management practices. The niche differentiation of AOB and AOA in contrasting soils have been functionally demonstrated using DNA-SIP (stable isotope probing) methods, which have shown that AOA dominate nitrification processes in acidic soils, while AOB dominated in neutral, alkaline and N-rich soils. Finally, we discuss the composition and activity of ammonia oxidizers in paddy soils, as well as the mitigation of the greenhouse gas nitrous oxide (N2O) emissions and nitrate leaching via inhibition of nitrification by both AOB and AOA. © 2012 Shen, Zhang, Di and He.


Sun R.,CAS Research Center for Eco Environmental Sciences | Wang Z.,CAS Research Center for Eco Environmental Sciences | Chen L.,CAS Research Center for Eco Environmental Sciences | Wang W.,Chinese Research Academy of Environmental Sciences
Journal of the American Water Resources Association | Year: 2013

Understanding the impacts that influence water quality is critical to the development of best management practices at the large watershed scale. This study describes the spatiotemporal variation in surface water quality and identifies their main impact in the Haihe River basin, China. Multivariate statistical techniques are applied to analyze the similarities among the sampling sites and to identify the main pollution sources in surface water. Results show that: (1) the basin can be clustered into two regions, water quality being better in the mountainous vs. plain regions; (2) water quality improves due to implementation of a strict state policy on environmental pollution control, prodded by the hosting of the Olympic games in the cities of Beijing and Tianjin; and (3) agricultural and residential land uses as well as livestock-breeding are the main sources affecting water quality in the mountainous regions, whereas rural waste discharge - including domestic waste sewage, human and animal feces, and solid waste - significantly influences water quality in the plain regions. The waste discharge of industrial factories may be a significant source of water pollution in the plain regions. Results indicate that the environmental management from pollution sinks and sources, long-lasting legal framework, and adequate economic incentives should be improved to optimize the large-scale watershed management under the background of the rapid development of countries like China. © 2013 American Water Resources Association.


Xu Y.D.,CAS Research Center for Eco Environmental Sciences | Xu Y.D.,Chinese Research Academy of Environmental Sciences | Fu B.J.,CAS Research Center for Eco Environmental Sciences | He C.S.,Lanzhou University | He C.S.,Western Michigan University
Hydrology and Earth System Sciences | Year: 2013

Check dams are commonly used for soil conservation. In the Loess Plateau of China, check dams have been widely constructed as the principal means to retain floodwa-ter and intercept soil sediments since the 1970s. For instance, there are more than 6572 check dams in the Yanhe watershed with an area of 7725 km2 in the Loess Plateau. However, little research has been done to quantify the hydrological effects of the check dams. In this research, the SWAT model (Soil and Water Assessment Tool) was applied to simulate the runoff and sediment in the Yanhe watershed. We treated the 1950s to 1960s as the reference period since there were very few check dams during the period. The model was firstly calibrated and validated in the reference period. The calibrated model was then used in the later periods to simulate the hydrological effects of the check dams. The results showed that the check dams had a regulation effect on runoff and a retention effect on sediment. From 1984 to 1987, the runoff in rainy season (from May to October) decreased by 1.54 m3 s -1 (14.7 %) to 3.13 m3 s-1 (25.9 %) due to the check dams; while in dry season (from November to the following April), runoff increased by 1.46 m3 s-1 (60.5%) to 1.95 m3 s-1 (101.2 %); the sediment in rainy season decreased by 2.49 × 106 ton (34.6 %) to 4.35 × 106 ton (48.0 %). From 2006 to 2008, the runoff in rainy season decreased by 0.79 m3 s -1 (15.5 %) to 1.75 m3 s-1 (28.9 %), and the runoff in dry season increased by 0.51 m3 s-1 (20.1 %) to 0.97 m3 s-1 (46.4 %); the sediment in rainy season decreased by 2.03× 106 ton (79.4 %) to 3.12 × 10 6 ton (85.5 %). Construction of the large number of check dams in the Loess Plateau has enhanced the region's capacity to control the runoff and sediment. In the Yanhe watershed, the annual runoff was reduced by less than 14.3 % due to the check dams; and the sediment in rainy season was blocked by up to 85.5 %. Thus, check dams are effective measures for soil erosion control in the Loess Plateau. © Author(s) 2013.


Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Tangshan College | Niu H.,CAS Research Center for Eco Environmental Sciences | Pan Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Analytical Chemistry | Year: 2010

In the present study, chitosan-coated octadecyl-functionalized magnetite nanoparticles (Fe3O4-C18-chitosan MNPs) are synthesized and used as an adsorbent to extract trace analytes from environmental water samples. The magnetic nanoparticles, 20 nm in diameter, are of uniform size and have a high magnetic saturation value of 52 emu g -1, which endue the adsorbent with a large surface area and convenience of isolation. The anionic pollutants, perfluorinated compounds (PFCs), are trapped by the octadecyl group of the interior hydrophobic layer. The positively charged chitosan polymer coating also contributes to PFC enrichment. At the same time, the coating improves the dispersibility of MNPs in aqueous solution and enhances the anti-interference ability of the adsorbent to natural organic macromolecules in complex samples by size exclusion or electrostatic repulsion. A liquid chromatography-tandem mass spectrometry system is employed in the determination of PFCs after preconcentration with the MNP adsorbent. The predominant factors affecting preconcentration are investigated and optimized. Under the selected conditions, concentration factors of 1000 are achieved by extracting the analytes from 500 mL of several environmental water samples and concentrating the eluants to 0.5 mL with a nitrogen flow. The method detection limits obtained for perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), perluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and perfluorotetradecanoic acid (PFTA) in Gaobeidian wastewater are 0.24, 0.093, 0.24, 0.14, 0.075, 0.24, and 0.17 ng L-1, respectively. Recoveries of PFOA, PFOS, PFNA, PFDA, PFUnDA, PFDoDA, and PFTA are in the ranges of 88-108%, 63-112%, 79-109%, 56-107%, 66-106%, 56-106%, and 66-103% for four spiked water samples with low relative standard deviation (2-8%), which indicates good method precision. The advantages of this novel adsorbent are high extraction efficiency, anti-interference, and convenient operation. © 2010 American Chemical Society.


Kong F.,Harbin Institute of Technology | Wang A.,Harbin Institute of Technology | Wang A.,CAS Research Center for Eco Environmental Sciences | Ren H.-Y.,Harbin Institute of Technology
Bioresource Technology | Year: 2015

A new integrated system, embedding a modular bioelectrochemical system (BES) with surrounding electrode deployment into an anaerobic sludge reactor (ASR), was developed to improve azo dye decolorization. Results demonstrated that the AO7 decolorization and COD removal can be improved without co-substrate in such system. The kinetic rate of decolorization (0.54h-1) in integrated system was 1.4-fold and 54.0-fold higher than that in biocathode BES (0.39h-1) and ASR (0.01h-1), respectively. COD can be removed after cleavage of azo bond, different from biocathode BES. The combined advantages of this integrated system were achieved by the cooperation of biocathode in modular BES and sludge in ASR. Biocathode was a predominant factor in AO7 decolorization, and anaerobic sludge contributed negligibly to AO7 reduction decolorization but mostly in the COD removal. These results demonstrated the great potential of integrating a BES module with anaerobic treatment process for azo dye treatment. © 2014 Elsevier Ltd.


Zhao X.,Chinese Research Academy of Environmental Sciences | Cai Y.,CAS Research Center for Eco Environmental Sciences | Wu F.,Chinese Research Academy of Environmental Sciences | Pan Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Microchemical Journal | Year: 2011

A novel method was developed for solid-phase extraction (SPE) of perfluorinated compounds (PFCs) from environmental water samples using cetyltrimethylammonium bromide (CTAB) coated Fe3O4 nanoparticles (Fe3O4 NPs) as an adsorbent. The magnetic nanosized adsorbent has a large surface area and superparamagnetic properties. This gives it a high extraction capacity and allows for convenient isolation by a magnetic field. Compared with other SPE methods and our previous work on PFCs, this method exhibited a fairly good analytical performance and required a small amount of sorbent (50mg) and short pretreatment times (30min) for 800mL environmental water samples. Seven PFCs, including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and perfluorotetradecanoic acid (PFTA), extracted by the optimized method were determined by high-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC/ESI-MS/MS). A concentration factor of 1600 was achieved when extracting 800mL of several environmental water samples. Detection limits obtained for PFOA, PFOS, PFNA, PFDA, PFUnDA, PFDoDA and PFTA were 0.14, 0.022, 0.31, 0.23, 0.11, 0.16, 0.091ng/L, respectively. The relative standard deviations of recoveries ranged from 1 to 8%, indicating good method precision. © 2011 Elsevier B.V.


Hu Y.,CAS Research Center for Eco Environmental Sciences | Rillig M.C.,Free University of Berlin | Rillig M.C.,Berlin Brandenburg Institute of Advanced Biodiversity Research BBIB | Xiang D.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
PLoS ONE | Year: 2013

Arbuscular mycorrhizal (AM) fungi are ubiquitous symbionts of higher plants in terrestrial ecosystems, while the occurrence of the AM symbiosis is influenced by a complex set of abiotic and biotic factors. To reveal the regional distribution pattern of AM fungi as driven by multiple environmental factors, and to understand the ecological importance of AM fungi in natural ecosystems, we conducted a field investigation on AM fungal abundance along environmental gradients in the arid and semi-arid grasslands of northern China. In addition to plant parameters recorded in situ, soil samples were collected, and soil chemo-physical and biological parameters were measured in the lab. Statistical analyses were performed to reveal the relative contribution of climatic, edaphic and vegetation factors to AM fungal abundance, especially for extraradical hyphal length density (HLD) in the soil. The results indicated that HLD were positively correlated with mean annual temperature (MAT), soil clay content and soil pH, but negatively correlated with both soil organic carbon (SOC) and soil available N. The multiple regressions and structural equation model showed that MAT was the key positive contributor and soil fertility was the key negative contributor to HLD. Furthermore, both the intraradical AM colonization (IMC) and relative abundance of AM fungi, which was quantified by real-time PCR assay, tended to decrease along the increasing SOC content. With regard to the obvious negative correlation between MAT and SOC in the research area, the positive correlation between MAT and HLD implied that AM fungi could potentially mitigate soil carbon losses especially in infertile soils under global warming. However, direct evidence from long-term experiments is still expected to support the AM fungal contribution to soil carbon pools. © 2013 Hu et al.


Shan W.,CAS Research Center for Eco Environmental Sciences | Shan W.,Hebei University | Liu F.,CAS Research Center for Eco Environmental Sciences | He H.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Catalysis Today | Year: 2012

A Ce-Ti based (CeO 2-TiO 2) catalyst prepared by an optimized homogeneous precipitation method showed excellent NH 3-SCR activity, high N 2 selectivity, broad operation temperature window, and high resistance to space velocity (even under a high gas hourly space velocity (GHSV) of 500,000 h -1). Compared with V 2O 5-WO 3/TiO 2 and Fe-ZSM-5 catalysts, the CeO 2-TiO 2 catalyst showed better catalytic performance for NH 3-SCR. Under a more realistic condition of simulated diesel engine exhaust, the monolith catalyst of CeO 2-TiO 2 showed over 90% NO x conversion from 250 to 450°C under a GHSV of 20,000 h -1 in the presence of H 2O, CO 2, and C 3H 6. The high dispersion of active CeO 2 on TiO 2 in the process of homogenous precipitation and the synergistic effects between CeO 2 and TiO 2 in CeO 2-TiO 2 are important reasons for the high NH 3-SCR activity. © 2011 Elsevier B.V.


Liu G.,CAS Research Center for Eco Environmental Sciences | Liu G.,Hong Kong Baptist University | Cai Z.,Hong Kong Baptist University | Zheng M.,CAS Research Center for Eco Environmental Sciences
Chemosphere | Year: 2014

The European Union has proposed that polychlorinated naphthalenes (PCNs) should be included in the annexes of the Stockholm Convention on Persistent Organic Pollutants, signifying that there will be an increase in activities aimed at reducing PCN emissions. It has been speculated that the unintentional formation and emission of PCNs from industrial activities are the main current sources, because they have ceased to be manufactured as industrial chemicals in many countries. In this review, we provide a brief overview of recent progress in research into the unintentional formation and emission of PCNs from various industries that use thermal processes. The sampling and analysis of PCNs, and their formation mechanisms during thermal processes, are reviewed and discussed. The emission levels, emission profiles, and emission factors of PCNs from a number of industries that use thermal processes are summarized and compared, and this will provide helpful information for planning PCN source control measures and studying the source-receptor relationships of PCNs. © 2013 Elsevier Ltd.


Li X.,CAS Research Center for Eco Environmental Sciences | Li Y.,CAS Research Center for Eco Environmental Sciences | Zhang Q.,CAS Research Center for Eco Environmental Sciences | Wang P.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Chemosphere | Year: 2011

The concern about emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) from steel industrial parks has increased in the past decades. In this study, polyurethane foam (PUF)-disk based passive air samples were collected in and around a big steel industrial park of Anshan, Northeast China from June 2008 to March 2009. The levels, seasonal variations and potential sources of PCDD/Fs, PCBs and PBDEs in the atmosphere around the steel industrial complex were investigated, and potential contribution of these three groups of persistent organic pollutants (POPs) from iron and steel production was also assessed. The air concentrations of ∑17PCDD/Fs (summer: 0.02-2.77pgm-3; winter: 0.20-9.79pgm-3), ∑19PCBs (summer: 23.5-155.8pgm-3; winter: 14.6-81.3pgm-3) and ∑13PBDEs (summer: 2.91-10.7pgm-3; winter: 1.10-3.89pgm-3) in this targeted industrial park were relatively low in comparison to other studies, which implied that the industrial activities of iron and steel had not resulted in serious contamination to the ambient air in this area. On the whole, the air concentrations of PCDD/Fs in winter were higher than those of summer, whereas the concentrations of PCBs and PBDEs showed opposite trends. The result from principal component analysis indicated that coal combustion might be the main contributor of PCDD/F sources in this area. © 2011 Elsevier Ltd.


Wang M.,CAS Research Center for Eco Environmental Sciences | Markert B.,International Institute of Higher Education, Zittau | Chen W.,CAS Research Center for Eco Environmental Sciences | Peng C.,CAS Research Center for Eco Environmental Sciences | Ouyang Z.,CAS Research Center for Eco Environmental Sciences
Environmental Monitoring and Assessment | Year: 2012

In order to evaluate the current state of the environmental quality of soils in Beijing, we investigated contents of 14 metals in Beijing urban soils inside the 5th ring road by even grids sampling. Statistic analyses were conducted to identify possible heavy metal pollutants, as well as the effects of land uses on their accumulation. Our results revealed that the urban soils in Beijing were contaminated by Cd, Pb, Cu, and Zn. Land uses and urbanization ages affected the accumulation of the four heavy metals in soils significantly. Soils in industrial areas have the highest average Cu and Zn contents, while Pb contents in park areas and Cd in agricultural areas are the highest. The accumulations of Pb and Zn in urban soils increase significantly with sampling plots approaching the city center. And Pb, Cd, and Zn contents in soils in traffic areas also tend to increase in the city center. However, residential areas have the lowest contents of all the four heavy metals. © Springer Science+Business Media B.V. 2012.


Leite Ribeiro M.,Ecole Polytechnique Federale de Lausanne | Blanckaert K.,Ecole Polytechnique Federale de Lausanne | Blanckaert K.,CAS Research Center for Eco Environmental Sciences | Roy A.G.,University of Waterloo | Schleiss A.J.,Ecole Polytechnique Federale de Lausanne
Journal of Geophysical Research: Earth Surface | Year: 2012

Confluences with relatively low discharge and momentum flux ratios where a small steep tributary with a high supply of poorly sorted sediment joins a large, low-gradient main channel commonly occur in nature, but they have not yet been investigated. Measurements of the three-dimensional velocity field, turbulence, sediment transport, bed material grain size and morphology are reported in a laboratory setting that is representative of confluences on the Upper Rhone River, Switzerland. The difference between the low-flow depth in the steep tributary and the higher flow depth in the main channel creates a marked bed discordance in the tributary zone. Due to this bed discordance, the tributary flow penetrates into the main channel mainly in the upper part of the water column, whereas the main-channel flow is hardly hindered by the tributary in the lower part of the water column, giving rise to a two-layer flow structure in the confluence zone. In confluences with high supply of coarse sediment from the tributary, the development of a deposition bar downstream from the confluence reduces the flow area and causes flow acceleration that contributes to an increase in sediment transport capacity. The sediment supplied by the tributary is mainly sorted and transported on the face of the bar by the near-bed flow originating from the main channel. The sediment transport capacity is further increased by the three-dimensionality of the flow, which is characterized by maximum velocities occurring near the bed, and by a considerable increase in turbulent kinetic energy generated in the shear layer at the interface of the flows originating from the main channel and the tributary. A conceptual model is proposed for the hydro-morpho-sedimentary processes, and compared to existing conceptual models for confluences with different characteristics. © 2012 by the American Geophysical Union.


Liu G.,CAS Research Center for Eco Environmental Sciences | Liu G.,Hong Kong Baptist University | Liu W.,CAS Research Center for Eco Environmental Sciences | Cai Z.,Hong Kong Baptist University | Zheng M.,CAS Research Center for Eco Environmental Sciences
Journal of Hazardous Materials | Year: 2013

The coking process has been found to be an important source of unintentionally produced persistent organic pollutants (UP-POPs). However, the concentrations, profiles, and emission factors of UP-POPs in fly ash from coke plants have not been studied. In this study, six UP-POPs (polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), hexachlorobenzene (HxCBz), and pentachlorobenzene (PeCBz)) were identified and quantified in fly ash from eight coke plants. The average concentrations of the PCDDs, PCDFs, and "dioxin-like" PCBs were 1.5, 2.26, and 0.26pgTEQg-1, respectively, and the average concentrations of the PCNs, HxCBz, and PeCBz were 256, 290, and 146pgg-1, respectively. The proportion each homolog contributed to the total concentration of the PCDFs, PCBs, and PCNs decreased with increasing chlorination level. The PCDFs contributed the biggest proportion of the total UP-POPs toxic equivalents (TEQs), and the average emission factors in fly ash were 10.5, 17.3, and 1.82ngTEQt-1 for the PCDDs, PCDFs, and "dioxin-like" PCBs, respectively, and 1792, 2028, and 1025ngt-1 for the PCNs, HxCBz, and PeCBz, respectively. These data are essential for establishing an integrated UP-POP release inventory. © 2013 Elsevier B.V.


Liu G.,CAS Research Center for Eco Environmental Sciences | Zheng M.,CAS Research Center for Eco Environmental Sciences | Jiang G.,CAS Research Center for Eco Environmental Sciences | Cai Z.,Hong Kong Baptist University | Wu Y.,China National Center for Food Safety Risk Assessment
TrAC - Trends in Analytical Chemistry | Year: 2013

The main objective of the Stockholm Convention on Persistent Organic Pollutants (POPs) is to protect human health and the environment from overexposure to POPs. As one of the signatories to the Stockholm Convention, China has built significant capacity and carried out intensive studies on sources of emissions, levels of environmental pollution, and risk assessment associated with dioxins in recent years. Significant progress has been made in adopting and ratifying the Stockholm Convention.This article provides a brief overview of recent progress in capacity building for dioxin analysis, source identification and quantification of dioxin emissions, environmental monitoring of dioxin contamination, and risk assessment of human exposure to dioxins in China. © 2013 Elsevier Ltd.


Wu S.,Zhejiang University of Technology | Zhang L.,CAS Research Center for Eco Environmental Sciences | Chen J.,Zhejiang University of Technology
Applied Microbiology and Biotechnology | Year: 2012

Paracetamol (4'-hydroxyacetanilide, N-acetyl-paminophenol, acetaminophen, and paracetamol) is a widely used over-the-counter analgesic and antipyretic drug. Paracetamol and structural analogs are ubiquitous in the natural environment and easily accumulate in aquatic environment, which have been detected in surface waters, wastewater, and drinking water throughout the world. Paracetamol wastewater is mainly treated by chemical oxidation processes. Although these chemical methods may be available for treating these pollutants, the harsh reaction conditions, the generation of secondary pollutants, and the high operational cost associated with these methods have often made them not a desirable choice. Biodegradation of paracetamol is being considered as an environmentally friendly and low-cost option. The goal of this review is to provide an outline of the current knowledge of biodegradation of paracetamol in the occurrence, degrading bacteria, and proposed metabolic/ biodegrading pathways, enzymes and possible intermediates. The comprehensive understanding of the metabolic pathways and enzyme systems involved in the utilization of paracetamol means will be helpful for optimizing and allowing rational design of biodegradation systems for paracetamol-contaminated wastewater. © Springer-Verlag Berlin Heidelberg 2012.


Lu J.,CAS Research Center for Eco Environmental Sciences | Lu J.,Tianjin Institute of Urban Construction | Liu H.,CAS Research Center for Eco Environmental Sciences | Liu R.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Powder Technology | Year: 2013

A nanostructured Fe-Al-Mn trimetal oxide adsorbent for phosphate removal with a Fe:Al:Mn molar ratio of 3:3:1 was prepared using simultaneous oxidation and coprecipitation method. The adsorbent was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) with an EDAX (energy dispersive analysis of X-ray). The results indicated that the Fe-Al-Mn trimetal oxide was amorphous and nanostructured. Zeta potential measurements showed that it possessed a high isoelectric point (around 9). The phosphate removal gradually decreased with the increasing of pH(4-10.5). The adsorption isotherms on the adsorbent were described by Langmuir, Freundlich and Temkin models at pH6.8 and followed the fitting order: Freundlich>Temkin>Langmuir. At 25°C, the maximum adsorption capacity for the adsorbent was about 48.3mg/g, which was higher than their reported single component oxide. The kinetic data were described better by the pseudo-second-order adsorption kinetic rate model. Thermodynamic analyses indicated that the phosphate adsorption on the Fe-Al-Mn trimetal oxide was endothermic and spontaneous in nature. The sequence of coexisting anions studied competing with phosphate was SiO 3 2->HCO 3 ->SO 4 2-. The results of zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that electrostatic attraction and replacement of surface hydroxyl groups (MOH) by phosphate via the formation of inner-sphere complex were the main adsorption mechanism. The Fe-Al-Mn trimetal oxide with good specific affinity towards phosphate was a promising adsorbent for phosphate removal from natural waters and municipal wastewaters. © 2012 Elsevier B.V.


Wang M.,CAS Research Center for Eco Environmental Sciences | Bai Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Chen W.,CAS Research Center for Eco Environmental Sciences | Markert B.,International Institute of Higher Education, Zittau | And 2 more authors.
Environmental Pollution | Year: 2012

Ecological risks of heavy metals in urban soils were evaluated using Beijing, China as an example. Cadmium, Cu, Zn, Pb, Cr and Ni contents of 233 surface soils sampled by 1 min latitude × 1 min longitude grid were used to identify their spatial distribution patterns and potential emission sources. Throughout the city, longer the duration of urbanization greater was the accumulations of heavy metals especially, Cd, Cu, Pb, and Zn. The soil Zn mainly came from the wears of vehicular tires. Point source emissions of heavy metals were few and far in the downwind south-east quadrant of Beijing. The calculated risk indices showed potential median eco-risks in the ancient central city. No potential high eco-risk due to soil-borne heavy metals was found. The potential medium eco-risk areas in Beijing would expand from the initial 24 to 110 km 2 if soil pH were to reduce by 0.5 units in anticipation. © 2011 Elsevier Ltd. All rights reserved.


Gondal M.A.,King Fahd University of Petroleum and Minerals | Chang X.,King Fahd University of Petroleum and Minerals | Chang X.,Nanjing University of Aeronautics and Astronautics | Ali M.A.,King Fahd University of Petroleum and Minerals | And 3 more authors.
Applied Catalysis A: General | Year: 2011

The adsorption (under dark condition) and photodegradation behaviors of Rhodamine B molecules on BiOBr under visible (532 nm) pulsed laser exposure were studied and reported for the first time. The adsorption kinetics/isotherm behaviors and thermodynamic process (adsorption dynamical parameters) occurred on as-prepared BiOBr were investigated. The photodegradation mechanisms, effects of BiOBr dosage and pulsed laser energy on dye removal efficiency in the presence of BiOBr particles were studied as well. Furthermore, the photodegradation of other kinds of Rhodamine dyes such as Rhodamine 6G, Sulforhodamine B and Sulforhodamine 640 were initially investigated and compared under 532 nm pulsed laser exposure. The study also demonstrated that the dissolved oxygen plays a very significant role in the photo-catalytic decomposition of Rhodamine. The BiOBr catalyst was found intact even under acidified conditions showing good stability of the catalyst. © 2011 Elsevier B.V. All rights reserved.


Zhang L.,Zhejiang University of Technology | Zhang L.,CAS Research Center for Eco Environmental Sciences | Hu J.,Zhejiang University of Technology | Zhu R.,Zhejiang University of Technology | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2013

Three bacterial strains utilizing paracetamol as the sole carbon, nitrogen, and energy source were isolated from a paracetamol-degrading aerobic aggregate, and assigned to species of the genera Stenotrophomonas and Pseudomonas. The Stenotrophomonas species have not included any known paracetamol degraders until now. In batch cultures, the organisms f1, f2, and fg-2 could perform complete degradation of paracetamol at concentrations of 400, 2,500, and 2,000 mg/L or below, respectively. A combination of three microbial strains resulted in significantly improved degradation and mineralization of paracetamol. The co-culture was able to use paracetamol up to concentrations of 4,000 mg/L, and mineralized 87.1 % of the added paracetamol at the initial of 2,000 mg/L. Two key metabolites of the biodegradation pathway of paracetamol, 4-aminophenol, and hydroquinone were detected. Paracetamol was degraded predominantly via 4-aminophenol to hydroquinone with subsequent ring fission, suggesting new pathways for paracetamol-degrading bacteria. The degradation of paracetamol could thus be performed by the single isolates, but is stimulated by a synergistic interaction of the three-member consortium, suggesting a possible complementary interaction among the various isolates. The exact roles of each of the strains in the consortium need to be further elucidated. © 2012 Springer-Verlag.


Yin J.,CAS Research Center for Eco Environmental Sciences | Cui Y.,CAS Institute of Chemistry | Yang G.,CAS Institute of Chemistry | Yang G.,Hebei University | Wang H.,CAS Research Center for Eco Environmental Sciences
Chemical Communications | Year: 2010

Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release are fabricated by the combination of template synthesis and ATRP grafting. The release of R-propranolol from the imprinted nanotubes in rats is restricted while the release of pharmacologically active S-enantiomer is greatly promoted. © The Royal Society of Chemistry.


Yu X.,Catalonia Institute for Energy Research IREC | Yu X.,CAS Institute of Process Engineering | Shavel A.,Catalonia Institute for Energy Research IREC | An X.,University College London | And 5 more authors.
Journal of the American Chemical Society | Year: 2014

Cu2ZnSnS4, based on abundant and environmental friendly elements and with a direct band gap of 1.5 eV, is a main candidate material for solar energy conversion through both photovoltaics and photocatalysis. We detail here the synthesis of quasi-spherical Cu 2ZnSnS4 nanoparticles with unprecedented narrow size distributions. We further detail their use as seeds to produce CZTS-Au and CZTS-Pt heterostructured nanoparticles. Such heterostructured nanoparticles are shown to have excellent photocatalytic properties toward degradation of Rhodamine B and hydrogen generation by water splitting. © 2014 American Chemical Society.


Luo X.,Nanchang Hangkong University | Ding L.,Nanchang Hangkong University | Luo J.,CAS Research Center for Eco Environmental Sciences
Journal of Chemical and Engineering Data | Year: 2015

Metal organic frameworks (MOFs) have been regarded as robust adsorbents for the adsorptive removal of organic pollutants because of their unique characteristics. However, the application of MOFs in the removal of metals from water is still rare. In this paper, amino-functionalization of Cr-based MOFs MIL-101 are modified through coordination bonding of unsaturated Cr metal centers with the -NH2 group in ethylenediamine (ED), and we demonstrate their excellent performance for the removal of Pb(II) ions from water. The Fourier transform infrared verifies that the ethylenediamine was grafted successfully on MIL-101. Furthermore, the results of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy show that the structure of ED-MIL-101 with an appropriate amount of ED almost does not collapse and retains the original performance of MIL-101. The adsorption capacity of ED-MIL-101, which is more than five times that of MIL-101, is 81.09 mg·g-1 for Pb(II) ions from aqueous samples. The selectivity coefficients of ED-MIL-101 for Pb(II)/Cu(II), Pb(II)/Zn(II), Pb(II)/Co(II), and Pb(II)/Ni(II) are 6.92, 24.02, 15.69, and 14.53, respectively. The adsorption kinetics of Pb(II) ions shows that the process fits well with a pseudo-second-order model, and the adsorption equilibrium time is only about 30 min. Moreover, the practical application of ED-MIL-101 achieves almost 97.22% removal efficiency for Pb(II) ions. These results indicate that ED-MIL-101 has great potential in selectively removing Pb(II) ions from water environment. © 2015 American Chemical Society.


Shan W.,CAS Research Center for Eco Environmental Sciences | Shan W.,Hebei University | Liu F.,CAS Research Center for Eco Environmental Sciences | He H.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2012

A superior Ce-W-Ti mixed oxide catalyst prepared by a facile homogeneous precipitation method showed excellent NH 3-SCR activity and 100% N 2 selectivity with broad operation temperature window and extremely high resistance to space velocity, which is a very promising catalyst for NO x abatement from diesel engine exhaust. The excellent catalytic performance is associated with the highly dispersed active Ce and promotive W species on TiO 2. The introduction of W species could increase the amount of active sites, oxygen vacancies, and Brønsted and Lewis acid sites over the catalyst, which is also beneficial to improve the low temperature activity by facilitating " fast SCR" reaction and enhance both of the high temperature activity and N 2 selectivity simultaneously by inhibiting the unselective oxidation of NH 3 at high temperatures. © 2011 Elsevier B.V..


Zhang G.,CAS Research Center for Eco Environmental Sciences | Mu Y.,CAS Research Center for Eco Environmental Sciences | Liu J.,CAS Research Center for Eco Environmental Sciences | Mellouki A.,French National Center for Scientific Research
Journal of Chromatography A | Year: 2012

Gas chromatography equipped with electron capture detector (GC-ECD) has been widely used for detecting atmospheric peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN). However, to the best of our knowledge, only a few capillary columns have been adopted for separation to achieve the direct and simultaneous analysis of the two atmospheric pollutants. This paper demonstrates a novel method for directly and simultaneously measuring atmospheric carbon tetrachloride (CCl4), PAN, and PPN using GC-ECD with a DB-1 separation column. The responses of the GC-ECD to PAN, PPN, and CCl4 were individually calibrated by using gas mixtures prepared via volatilization of synthesized solutions of PAN and PPN or high-purity CCl4 reagent in a Teflon Bag. The concentrations of PAN and PPN in the synthesized solutions were quantified by ion chromatography (IC). Further calibration of the GC-ECD for PAN was conducted by in situ photochemical formation of gaseous PAN which was quantified by a NOx analyzer. The two calibration methods agreed well with each other, and the overall uncertainties for measuring atmospheric PAN were estimated to be ±13% and ±15% based on the calibrations of IC and NOx, respectively. The detection limits (three times the signal to noise ratio) for PAN, PPN, and CCl4 were estimated to be 22, 36, and 5pptv (parts per trillion by volume), respectively. The atmospheric concentrations of these compounds were measured for several days in August in Beijing, and the values obtained in this study were found to be in good agreement with the data reported in the literature for Beijing using other GC-ECD methods. © 2012 Elsevier B.V.


Gondal M.A.,King Fahd University of Petroleum and Minerals | Chang X.,King Fahd University of Petroleum and Minerals | Chang X.,Nanjing University of Aeronautics and Astronautics | Sha W.E.I.,University of Hong Kong | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2013

The work presented here deals with the photoreduction in metallic silver nanoparticles onto the surface of Ag3PO4 and resulting photocatalytic activity enhancement toward degradation of dye molecules, namely Rhodamine B (Rh. B) as a model compound, from aqueous solution under UV or visible light irradiation. Our results clearly indicated that the photoactivity of Ag3PO4 was significantly enhanced by depositing an optimum amount of silver nanoparticles, even though the adsorption kinetics rate and capacity decreased after the silver nanoparticles agglomerate extensively. The surface plasmon resonance (SPR) excited between the silver nanoparticles and Rh. B interface is a physical origin and responsible for the boosted photoactivity, which strongly depends on the specific wavelength of the incident light. This work provides and suggests a novel scheme for Ag/Ag3PO4 composites having plasmonic effect on the interface with detailed experimental and theoretical study. © 2012 Elsevier Inc.


Liu F.,CAS Research Center for Eco Environmental Sciences | Asakura K.,Hokkaido University | Xie P.,Zhejiang University of Technology | Wang J.,Zhejiang University of Technology | He H.,CAS Research Center for Eco Environmental Sciences
Catalysis Today | Year: 2013

Environmental-friendly iron titanate (FeTiOx) catalyst is a potential candidate for the substitution of conventional V2O 5WO3 (MoO3)/TiO2 catalyst for the selective catalytic reduction of NOx with NH3 (NH 3-SCR) for the NOx elimination from stationary and mobile sources for environmental protection. To understand in-depth the nature of active structure in this FeTiOx catalyst for further catalyst redesign and activity improvement, the study of X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine-structure spectroscopy (EXAFS) combined with theoretical calculation is carefully performed. Different from the crystal structure of hematite Fe2O3, homogeneous edge shared Fe3+(O)2Ti4+ structure in FeTiOx catalyst prepared from Ti(SO4)2 precursor is obviously formed with crystallite phase, which shows the electronic inductive effect between Fe3+ and Ti4+ species, resulting in the high NO adsorption and oxidation ability of Fe3+ species and thus high catalytic activity and N2 selectivity in the NH 3-SCR reaction. In the future study, this specific edge shared Fe3+(O)2Ti4+ structure can be stabilized onto certain catalyst supports with large surface area for practical use, such as the catalytic removal of NOx from flue gas and diesel engine exhaust. © 2012 Elsevier B.V.


Zhang L.,Zhejiang University of Technology | Zhang L.,CAS Research Center for Eco Environmental Sciences | Zhang C.,Zhejiang University of Technology | Cheng Z.,Zhejiang University of Technology | And 2 more authors.
Chemosphere | Year: 2013

A new strain Mycobacterium cosmeticum byf-4 able to simultaneously degrade benzene, toluene, ethylbenzene, and o-xylene (BTE(o-)X) compounds has been isolated and identified previously in our laboratory. We further report here the extent of degradation of every BTE(o-)X component, and unravel the initial mechanism involved in BTE(o-)X degradation. This organism efficiently degrades all the BTE(o-)X components when these compounds are added either individually or as a composite mixture, and has a preference for toluene followed by benzene, ethylbenzene and then o-xylene. The significantly high carbon recovery indicated that the predominant fate for BTE(o-)X compounds was mineralization and incorporation into cell materials. The presence of BTE compounds in binary or ternary mixtures consistently had a negative effect on o-xylene degradation. The initial steps involved in the degradation of BTE(o-)X were investigated by isolation of metabolites and assay of reverse transcription RT-PCR. Isolation of metabolites suggested that the BTE(o-)X compounds were initially converted by a dioxygenase to their respective catechols. The gene sequence of the PCR amplicons revealed that this isolate contained a 454-bp toluene dioxygenase (TOD) fragment. The BTE(o-)X-specific induction of the genes encoding TOD was confirmed by RT-PCR analysis. These results indicated that TOD was possibly responsible for the initial steps of BTE(o-)X catabolism in M. cosmeticum byf-4. © 2012.


Hu Q.H.,University of Texas at Arlington | Sun G.X.,CAS Research Center for Eco Environmental Sciences | Gao X.B.,Wuhan University | Zhu Y.G.,CAS Research Center for Eco Environmental Sciences
Applied Geochemistry | Year: 2012

This work addresses the inter-conversion and sorption of inorganic As species in representative geological media. Through the sensitive quantification of As(III) and As(V) with liquid chromatography-inductively coupled plasma-mass spectrometry, and through integrated batch and column approaches, it is shown that natural media can either reduce or oxidize As species. Oxidation of As(III) to As(V) is shown in the Hanford sediment, while reduction of As(V) to As(III) is shown for the surface soil of Savannah River Site. Overall, the sorption distribution coefficient of As(V) onto geological media is much larger than that of As(III), and a reduction of the more sorptive As(V) to As(III) will lead to groundwater enrichment with As. Coupled with the different sorption behavior of As(III) and As(V), the inter-conversion of these species will strongly affect the geochemical cycling of redox-sensitive As in the subsurface. © 2012 Elsevier Ltd.


Nie Y.,CAS Research Center for Eco Environmental Sciences | Nie Y.,Beijing Research Institute of Chemical Defense | Qiang Z.,CAS Research Center for Eco Environmental Sciences | Zhang H.,CAS Research Center for Eco Environmental Sciences | Ben W.,CAS Research Center for Eco Environmental Sciences
Separation and Purification Technology | Year: 2012

The fate and seasonal variation of several typical endocrine-disrupting chemicals (EDCs), including estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), estriol (E3), bisphenol A (BPA) and 4-nonylphenol (NP), were investigated in a municipal sewage treatment plant (STP) employing an anaerobic/anoxic/oxic (A/A/O) process located in Beijing, China by monitoring their concentrations in both wastewater and activated sludge in four seasons throughout 2009. Results indicate that in summer, the examined STP could effectively remove 75.4% of E1 and more than 90% of all other studied EDCs from the wastewater. The biodegradation in the A/A/O process was the primary removal mechanism. Moreover, the removal of EDCs from the wastewater in the A/A/O bioreactor and their concentrations in the solid phase of return sludge exhibited an obvious seasonal fluctuation. The concentrations of EDCs in the effluent and return sludge were much higher in winter and spring than in summer and autumn, which was closely related to the microbial activity and the concentration of mixed liquor suspended solids (MLSS). Therefore, this study may raise a particular concern regarding the removal of EDCs from wastewater and the disposal of excess sludge in cold seasons. © 2011 Elsevier B.V. All rights reserved.


Jiang Y.,CAS Research Center for Eco Environmental Sciences | Li X.,CAS Research Center for Eco Environmental Sciences | Huang C.,Wuhan University | Wu X.,Sinohydro Resources Ltd
Knowledge-Based Systems | Year: 2014

Bilevel programming techniques deal with decision processes involving two decision makers with a hierarchical structure. In this paper, an augmented Lagrangian multiplier method is proposed to solve nonlinear bilevel programming (NBLP) problems. An NBLP problem is first transformed into a single level problem with complementary constraints by replacing the lower level problem with its Karush-Kuhn-Tucker optimality condition, which is sequentially smoothed by a Chen-Harker-Kanzow-Smale (CHKS) smoothing function. An augmented Lagrangian multiplier method is then applied to solve the smoothed nonlinear program to obtain an approximate optimal solution of the NBLP problem. The asymptotic properties of the augmented Lagrangian multiplier method are analyzed and the condition for solution optimality is derived. Numerical results showing viability of the approach are reported. © 2013 Elsevier B.V. All rights reserved.


Xu H.,National Climate Center | Taylor R.G.,University College London | Xu Y.,CAS Research Center for Eco Environmental Sciences
Hydrology and Earth System Sciences | Year: 2011

Quantitative evaluations of the impacts of climate change on water resources are primarily constrained by uncertainty in climate projections from GCMs. In this study we assess uncertainty in the impacts of climate change on river discharge in two catchments of the Yangtze and Yellow River Basins that feature contrasting climate regimes (humid and semi-arid). Specifically we quantify uncertainty associated with GCM structure from a subset of CMIP3 AR4 GCMs (HadCM3, HadGEM1, CCSM3.0, IPSL, ECHAM5, CSIRO, CGCM3.1), SRES emissions scenarios (A1B, A2, B1, B2) and prescribed increases in global mean air temperature (1 °C to 6 °C). Climate projections, applied to semi-distributed hydrological models (SWAT 2005) in both catchments, indicate trends toward warmer and wetter conditions. For prescribed warming scenarios of 1 °C to 6 °C, linear increases in mean annual river discharge, relative to baseline (1961-1990), for the River Xiangxi and River Huangfuchuan are +9% and 11% per +1 °C respectively. Intra-annual changes include increases in flood (Q05) discharges for both rivers as well as a shift in the timing of flood discharges from summer to autumn and a rise (24 to 93%) in dry season (Q95) discharge for the River Xiangxi. Differences in projections of mean annual river discharge between SRES emission scenarios using HadCM3 are comparatively minor for the River Xiangxi (13 to 17% rise from baseline) but substantial (73 to 121%) for the River Huangfuchuan. With one minor exception of a slight (-2%) decrease in river discharge projected using HadGEM1 for the River Xiangxi, mean annual river discharge is projected to increase in both catchments under both the SRES A1B emission scenario and 2° rise in global mean air temperature using all AR4 GCMs on the CMIP3 subset. For the River Xiangxi, there is substantial uncertainty associated with GCM structure in the magnitude of the rise in flood (Q05) discharges (-1 to 41% under SRES A1B and -3 to 41% under 2° global warming) and dry season (Q95) discharges (2 to 55% under SRES A1B and 2 to 39% under 2° global warming). For the River Huangfuchuan, all GCMs project a rise in the Q05 flow but there is substantial uncertainty in the magnitude of this rise (7 to 70% under SRES A1B and 2 to 57% under 2° global warming). Differences in the projected hydrological changes are associated with GCM structure in both catchments exceed uncertainty in emission scenarios. Critically, estimated uncertainty in projections of mean annual flows is less than that calculated for extreme (Q05, Q95) flows. The common approach of reporting of climate change impacts on river in terms of mean annual flows masks the magnitude of uncertainty in flows that are of most importance to water management. © Author(s) 2011.


Mu Q.,Shandong University | Mu Q.,Fred Hutchinson Cancer Research Center | Mu Q.,University of Washington | Jiang G.,CAS Research Center for Eco Environmental Sciences | And 5 more authors.
Chemical Reviews | Year: 2014

A recently reported incident of severe pulmonary fibrosis caused by inhaled polymer nanoparticles in seven female workers obtained much attention. In addition to the release of ENM waste from industrial sites, a major release of ENMs to environmental water occurs due to home and personal use of appliances, cosmetics, and personal products, such as shampoo and sunscreen. Airborne and aqueous ENMs pose immediate danger to the human respiratory and gastrointestinal systems. ENMs may enter other human organs after they are absorbed into the bloodstream through the gastrointestinal and respiratory systems. Practically, a thorough understanding of the fundamental chemical interactions between nanoparticles and biological systems has two direct impacts. First, this knowledge will encourage and assist experimental approaches to chemically modify nanoparticle surfaces for various industrial or medicinal applications.


Qiang Z.,CAS Research Center for Eco Environmental Sciences | Nie Y.,CAS Research Center for Eco Environmental Sciences | Nie Y.,Beijing Research Institute of Chemical Defense | Ben W.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemosphere | Year: 2013

Ozonation has been considered to be an effective means for the reduction of excess sludge in recent years. However, it remains largely unknown whether hydrophobic organic micro-pollutants, which are originally adsorbed on activated sludge, will be released into wastewater upon ozonation because of sludge solubilization. This study investigated the degradation efficiencies of several typical endocrine-disrupting chemicals (EDCs) during sludge ozonation, including estrone (E1), estriol (E3), 17α-ethynylestradiol (EE2), bisphenol A (BPA), and 4-nonylphenol (NP). Results indicate that the EDCs present in activated sludge could be effectively removed by O3 even though the apparent rate constants in sludge were 3-4 orders of magnitude lower than those in water. However, the applied O3 dose should be prudently controlled because a low dose (e.g., 29mgO3g-1SS) may lead to an increase of BPA and NP concentrations in the liquid phase of activated sludge. Furthermore, H2O2 addition or pH adjustment could improve the removal of most studied EDCs, but exert a negative effect on the more hydrophobic and refractory compound, NP. © 2012 Elsevier Ltd.


Colombo C.,University of Molise | Palumbo G.,University of Molise | He J.-Z.,CAS Research Center for Eco Environmental Sciences | Pinton R.,University of Udine | Cesco S.,Free University of Bozen Bolzano
Journal of Soils and Sediments | Year: 2014

Purpose: The rationale of this paper is to review the state of the art regarding the biotic and abiotic reactions that can influence Fe availability in soils. In soil, the management-induced change from oxic to anoxic environment results in temporal and spatial variations of redox reactions, which, in turn, affect the Fe dynamics and Fe mineral constituents. Measuring the Fe forms in organic complexes and the interaction between bacteria and Fe is a major challenge in getting a better quantitative understanding of the dynamics of Fe in complex soil ecosystems. Materials and methods: We review the existing literature on chemical and biochemical processes in soils related with the availability of Fe that influences plant nutrition. We describe Fe acquisition by plant and bacteria, and the different Fe-organic complexes in order to understand their relationships and the role of Fe in the soil carbon cycle. Results and discussion: Although total Fe is generally high in soil, the magnitude of its available fraction is generally very low and is governed by very low solubility of Fe oxides. Plants and microorganisms can have different strategies in order to improve Fe uptake including the release of organic molecules and metabolites able to form complexes with FeIII. Microorganisms appear to be highly competitive for Fe compared with plant roots. Crystalline Fe and poorly crystalline (hydro)oxides are also able to influence the carbon storage in soil. Conclusion: The solubility of crystalline Fe minerals in soil is usually very low; however, the interaction with plant, microbes, and organic substance can improve the formation of soluble FeIII complexes and increase the availability of Fe for plant growth. Microbes release siderophores and plant exudates (e.g., phytosiderophores, organic acids, and flavonoids), which can bind and solubilize the Fe present in minerals. The improved understanding of this topic can enable the identification of effective solutions for remedying Fe deficiency or, alternatively, restricting the onset of its symptoms and yield's limitations in crops. Therefore, development and testing of new analytical techniques and an integrated approach between soil biology and soil chemistry are important prerequisites. © 2013 Springer-Verlag Berlin Heidelberg.


Zheng Z.,CAS Research Center for Eco Environmental Sciences | Fu B.,CAS Research Center for Eco Environmental Sciences | Hu H.,CAS Research Center for Eco Environmental Sciences | Sun G.,U.S. Department of Agriculture
Landscape Ecology | Year: 2014

Ecosystem services are increasingly recognized as the foundations of a well-functioning society. Large-scale ecological restoration projects have been implemented around China with the goal of restoring and sustaining ecosystem services, especially in vulnerable semi-arid regions where soil and water resources are most stressed due to historic human activities. The relationships among ecosystem services are often driven by land-use changes. It is necessary to develop an applicable method to explore the relationships between ecosystem services and driving factors over time. We selected the Yanhe Basin on China’s Loess Plateau as the study area, which has experienced a large-scale Grain for Green Project (GGP), and quantified four ecosystem services (soil conservation, water retention, water yield, and crop production). The results of this study show that different trends have occurred for ecosystem services during 2000–2008. We found potential tradeoffs between soil conservation and water yield. Synergies may exist among water retention and soil conservation/water yield. Two types of preconditions were pointed out in the analysis process to define the potential relationships among ecosystem service variables. The correspondence analysis was used to explore its intrinsic linkage and its variations among ecosystem services, land uses, and spatial locations. It suggests that the intensities of the ecosystem services provided by most of land uses and the internal proportion of regulating service to provision service in a sub-basin has been changed by GGP, but the relative spatial patterns of ecosystem services are still being maintained in entire basin scale from 1980 to 2008. © 2014, Springer Science+Business Media Dordrecht.


Wang S.,CAS Research Center for Eco Environmental Sciences | Fu B.-J.,CAS Research Center for Eco Environmental Sciences | He C.-S.,Western Michigan University | Sun G.,U.S. Department of Agriculture | Gao G.-Y.,CAS Research Center for Eco Environmental Sciences
Forest Ecology and Management | Year: 2011

During the past few decades, China has implemented several large-scale forestation programs that have increased forest cover from 16.0% in the 1980s to 20.4% in 2009. In northern China, water is the most sensitive and limiting ecological factor. Understanding the dynamic interactions between forest ecosystems and water in different regions is essential for maximizing forest ecosystem services. We examined forest cover and runoff relationships in northern China using published data from a variety of sources. In the Loess Plateau region, forest cover is not correlated with annual precipitation (r=0.08, p>0.05) at micro (<50km2) and meso scales (50-1000km2), while they are positively correlated at macro (>1000km2) scale (r=0.77, p<0.05). Moreover, forest cover is negatively correlated with the runoff coefficient (r=-0.64, p<0.05). In Northwest China, natural forest distribution is highly correlated with annual precipitation (r=0.48, p<0.05) but not with the runoff coefficient (r=-0.09, p>0.05). In Northeast China, we found a positive relationship between forest cover and the runoff coefficient (r=0.77, p<0.05), but the correlation between forest cover and precipitation was not significant (r=0.28, p>0.05). The multiple stepwise regression analysis indicated that runoff was influenced by altitude, annual precipitation, forest cover, and PET (potential evapotranspiration) in Northeast China. We concluded that geographic differences could mask the true role of forests in the partitioning of rainfall into runoff and evapotranspiration (ET) in a catchment. In determining the forest-water relationship, one must consider climatic controls on ET in addition to forest cover. Forests could potentially enhance the complementary relationship between ET and PET. Therefore, a greater amount of ET in forested areas may decrease the PET on a regional scale. © 2011 Elsevier B.V.


Wang D.,CAS Research Center for Eco Environmental Sciences | Xing L.,CAS Research Center for Eco Environmental Sciences | Xie J.,CAS Research Center for Eco Environmental Sciences | Chow C.W.K.,SA Water Corporation | And 3 more authors.
Chemosphere | Year: 2010

China has a very complex water supply system which relies on many rivers and lakes. As the population and economic development increases, water quality is greatly impacted by anthropogenic processes. This seriously affects the character of the dissolved organic matter (DOM) and imposes operational challenges to the water treatment facilities in terms of process optimization. The aim of this investigation was to compare selected drinking water sources (raw) with different DOM character, and the respective treated waters after coagulation, using simple organic characterization techniques to obtain a better understanding of the impact of source water quality on water treatment. Results from the analyses of selected water samples showed that the dissolved organic carbon (DOC) of polluted waters is generally higher than that of un-polluted waters, but the specific UV absorbance value has the opposite trend. After resolving the high performance size exclusion chromatography (HPSEC) peak components of source waters using peak fitting, the twelve waters studied can be divided into two main groups (micro-polluted and un-polluted) by using cluster analysis. The DOM removal efficiency (treatability) of these waters has been compared using four coagulants. For water sources allocated to the un-polluted group, traditional coagulants (Al2(SO4)3 and FeCl3) achieved better removal. High performance poly aluminum chloride, a new type of composite coagulant, performed very well and more efficiently for polluted waters. After peak fitting the HPSEC chromatogram of each of the treated waters, average removal efficiency of the profiles can be calculated and these correspond well with DOC and UV removal. This provides a convenient tool to assess coagulation removal and coagulant selection. © 2010 Elsevier Ltd.


Tian H.,CAS Technical Institute of Physics and Chemistry | He J.,CAS Technical Institute of Physics and Chemistry | Liu L.,CAS Technical Institute of Physics and Chemistry | Wang D.,Beijing Research Institute of Chemical Defense | And 2 more authors.
Microporous and Mesoporous Materials | Year: 2012

Birnessite - type manganese oxides with very high surface areas (up to 154 m 2/g) were successfully prepared using a microemulsion process. The morphology, surface area, pore size, and the surface reducibility of these materials were readily tailored via the synthesis temperature. The physiochemical properties of the manganese oxides were characterized by means of XRD, TEM, SEM, BET and H 2-TPR techniques. These materials were also catalytically tested in HCHO oxidation, showing significantly high catalytic activity. It was found that the differences in catalytic performance of these materials were jointly attributed to the effects of the morphology, surface area and surface reducibility. The highly porous feature of the catalyst with nanospheres could allow HCHO molecules to easily diffuse onto catalytically active sites, which endows the nanospheres with high catalytic activity. The higher the surface area, the higher its catalytic activity. A higher surface reducibility offered a lower temperature of HCHO oxidation. The most active manganese catalyst (BSW-120) showed a 100% HCHO conversion at 100 °C. © 2011 Elsevier Inc. All rights reserved.


Luo L.,CAS Research Center for Eco Environmental Sciences | Luo L.,Princeton University | Lin S.,CAS Research Center for Eco Environmental Sciences | Lin S.,TUV Rheinland Mandy Co. | And 2 more authors.
Environmental Pollution | Year: 2012

Sequestration and diffusion of three polycyclic aromatic hydrocarbons (PAHs) in seven Chinese soils were investigated for up to 200 days in sterile soil microcosms as functions of soil property and aging time. The aging of the PAHs, assessed using a mild extractant that removes primarily the labile fraction, showed a biphasic behavior. The rapid diffusion from labile to nonlabile domains was mainly dependent upon the distribution of meso- and micropore fraction and total organic carbon content. Meanwhile, the slow diffusion was found to decrease with the increase of the content of soil organic carbon, particularly of hard organic carbon (p < 0.01) and the meso- and micropore fraction, as well as with the increasing molecular size of PAHs. This work offers evidence that analyses of organic carbon fractionation and porosity are important to adequately assess the mechanistic basis of sequestration and diffusion of organic contaminants in soils. © 2012 Elsevier Ltd. All rights reserved.


Lu N.,CAS Research Center for Eco Environmental Sciences | Sun G.,U.S. Department of Agriculture | Feng X.,CAS Research Center for Eco Environmental Sciences | Fu B.,CAS Research Center for Eco Environmental Sciences
Journal of Hydrology | Year: 2013

China is facing a growing water crisis due to climate and land use change, and rise in human water demand across this rapidly developing country. Understanding the spatial and temporal ecohydrologic responses to climate change is critical to sustainable water resource management. We investigated water yield (WY) responses to historical (1981-2000) and projected potential climate changes across a large and complex climatic and land cover gradients over the North-South Transect of Eastern China (NSTEC, a standard terrestrial transect of the International GeoBiological Project, IGBP). After an annual scale evapotranspiration (ET) model was validated with historical streamflow records from ten watersheds, the model was applied to the NSTEC that encompasses seven climatic zones. We found that (1) The spatial and temporal variations of WY were highly dependent on precipitation (P) patterns during 1981-2000. Overall, the influences of significant temperature (T) rise on the trend of WY were suppressed by the insignificant P change during 1981-2000. (2) The long-term mean WY by climatic zone had a similar pattern as P. The different climatic zones had differential contributions to the total volumetric WY of the NSTEC. Within each climatic zone, the volumetric WY for each land cover type was highly dependent on its area of each land cover. (3) Corresponding to the P pattern, the mean WY decreased from the low (South) to high latitude (North), but the rates of changes varied along the NSTEC. Along the NSTEC, the sensitivity of WY to potential T and P changes increased from the high latitude to the low latitude. Future potential changes in WY are likely to follow changes in P with some modification by changes in energy availability. We conclude that precipitation is a major driver for water resource availability, and reliable prediction of future precipitation change patterns is critical to hydrologic forecast across the study region. © 2012 Elsevier B.V.


Zhang L.,Wuhan University | Liang Y.,Jianghan University | Liang Y.,CAS Research Center for Eco Environmental Sciences | Meng L.,Wuhan University
Polymers for Advanced Technologies | Year: 2010

Thermo-sensitive amphiphilic copolymers, PVCL-PTrpAMT and PVCL-PVP-PTrpAMT of hydrophilic N-vinylcaprolactam (VCL), N-vinylpyrrolidone (NVP), and hydrophobic N-t-Boc-tryptophanamido-N'-methacryl thioureas (TrpAMT) monomers, were synthesized and characterized by 1H NMR, UV-spectroscopy, and GPC-MALLS. The cloud point (CP) measurement showed that hydrophobic PTrpAMT and hydrophilic PVP segments significantly altered the phase transition temperature of PVCL with comparable molecular weight in aqueous solution. The CP of PVP-PTrpAMT solution was 38.0°C, lower by 5.0°C than that of unmodified PVCL. In the presence of phosphate buffer saline (PBS), the CP value of the PVCL polymer decreased by ~2.0°C in comparison to that of the aqueous solution. Fluorescent spectroscopy and TEM studies revealed that PVCL-PTrpAMT and PVCL-PVP-PTrpAMT self-assembled into the spherical micelles, 30-70 nm in diameter, at concentrations over their CMCs in an aqueous solution. Cytotoxicity tests demonstrated that the PVCL copolymers were not harmful to cell viability, which may favor the use of the copolymers as potential thermo-sensitive polymers in pharmaceutical applications. © 2009 John Wiley & Sons, Ltd.


Zhang B.,CAS Research Center for Eco Environmental Sciences | Guo L.-H.,CAS Research Center for Eco Environmental Sciences | Greenberg M.M.,Johns Hopkins University
Analytical Chemistry | Year: 2012

Exposure of DNA to oxidative stress conditions results in the generation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo). 8-OxodGuo is genotoxic if left unrepaired. We quantified 8-oxodGuo lesions in double-stranded DNA films by using a photoelectrochemical DNA sensor in conjunction with a specific covalent labeling method. A lesion-containing DNA film was assembled on a SnO2 nanoparticle modified indium tin oxide electrode through layer-by-layer electrostatic adsorption. The lesions were covalently labeled with a biotin conjugated spermine derivative, and ruthenium tris(bipyridine) labeled streptavidin was introduced as the signal reporter molecule. Photocurrent increased with the number of lesions in the strand and decreased as the film was diluted with intact DNA. Quantification of 8-oxodGuo was achieved with an estimated detection limit of ∼1 lesion in 650 bases or 1.6 fmol of 8-oxodGuo on the electrode. Incubation of the film with a DNA base excision repair enzyme, E. coli formamidopyrimidine-DNA glycosylase (Fpg), resulted in complete loss of the signal, indicating efficient excision of the isolated lesions in the nucleotide. Oxidatively generated DNA damage to a double-stranded calf thymus DNA film by the Fenton reaction was then assessed. One 8-oxodGuo lesion in 520 bases was detected in DNA exposed to 50 μM Fe2+/200 μM H2O2. Treatment with Fpg reduced the photocurrent by 50%, indicating only partial excision of 8-oxodGuo. This suggests that tandem lesions, which are resistant to Fpg excision, are generated by the Fenton reaction. Unlike repair enzyme dependent methods, the sensor recognizes 8-oxodGuo in tandem lesions and can avoid underestimating DNA damage. © 2012 American Chemical Society.


Xiao S.,CAS Research Center for Eco Environmental Sciences | Xiao S.,Henan Polytechnic University | An W.,CAS Research Center for Eco Environmental Sciences | Chen Z.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Water Research | Year: 2012

A comprehensive quantitative microbial risk assessment (QMRA) of Cryptosporidium infection, considering pathogen removal efficiency, different exposure pathways and different susceptible subpopulations, was performed based on the result of a survey of source water from 66 waterworks in 33 major cities across China. The Cryptosporidium concentrations in source water were 0-6 oocysts/10 L, with a mean value of 0.7 oocysts/10 L. The annual diarrhea morbidity caused by Cryptosporidium in drinking water was estimated to be 2701 (95% confidence interval (CI): 138-9381) cases per 100,000 immunodeficient persons and 148 (95% CI: 1-603) cases per 100,000 immunocompetent persons, giving an overall rate of 149.0 (95% CI: 1.3-606.4) cases per 100,000 population. The cryptosporidiosis burden associated with drinking water treated with the conventional process was calculated to be 8.31 × 10-6 (95% CI: 0.34-30.93 × 10-6) disability-adjusted life years (DALYs) per person per year, which was higher than the reference risk level suggested by the World Health Organization (WHO), but lower than that suggested by the United States Environmental Protection Agency (USEPA). Sixty-six percent of the total health burden due to cryptosporidiosis that occurred in the immunodeficient subpopulation, and 90% of the total DALYs was attributed to adults aged 15-59 years. The sensitivity analysis highlighted the great importance of stability of the treatment process and the importance of watershed protection. The results of this study will be useful in better evaluating and reducing the burden of Cryptosporidium infection. © 2012 Elsevier Ltd.


Ottevanger W.,Technical University of Delft | Blanckaert K.,Technical University of Delft | Blanckaert K.,Ecole Polytechnique Federale de Lausanne | Blanckaert K.,Leibniz Institute of Freshwater Ecology and Inland Fisheries | And 2 more authors.
Geomorphology | Year: 2012

Insight is provided in hydrodynamic processes governing the velocity redistribution in sharp river bends based on simulations of three recent experiments by means of Blanckaert and de Vriend's (2003, 2010) reduced-order nonlinear model without curvature restrictions. This model successfully simulated the flow redistribution and the secondary flow in all three experiments. The results indicate that the flow redistribution is primarily governed by topographic steering, curvature variations and secondary flow, in a broad range of different configurations, including mildly to sharply curved bends, narrow to shallow bends, smooth to rough bends, bends with additional complexities such as horizontal recirculation zones or patches of riverbed vegetation. The relative importance of these three dominant processes is case dependent, and controlled by the parameters C f -1H/B, R/B and streamwise curvature variations. The first parameter characterizes a river reach, whereas the second and third parameters are characteristics of individual bends. Major differences exist between the hydrodynamic processes in mildly and sharply curved bends. First, velocity redistribution induced by curvature variations is negligible in mildly curved bends, but the dominant process in sharp bends. This result is relevant, because most meander models are based on the assumption of weak-curvature variations. Second, nonlinear hydrodynamic interactions play a dominant role in sharp bends, where mild-curvature models overpredict the secondary flow and in some cases even falsely identify it as the dominant process governing the velocity redistribution, which leads to unsatisfactory flow predictions. The reduction in secondary flow strength provoked by the nonlinear hydrodynamic interactions is accompanied by a reduction in the transverse bed slope, which reduces the effect of topographic steering. © 2011 Elsevier B.V..


Shi J.-b.,CAS Research Center for Eco Environmental Sciences | Shi J.-b.,Hong Kong Polytechnic University | Ip C.C.M.,Hong Kong Polytechnic University | Zhang G.,CAS Guangzhou Institute of Geochemistry | And 2 more authors.
Environmental Pollution | Year: 2010

The spatial and temporal variations of mercury (Hg) in sediments of the Pearl River Estuary (PRE) and the surrounding coastal area (South China Sea) were studied. In surface sediments, the concentrations of Hg ranged from 1.5 to 201 ng/g, with an average of 54.4 ng/g, displaying a decreasing trend with the distance from the estuary to the open sea. This pattern indicates that the anthropogenic emissions from the Pearl River Delta (PRD) region are probably the main sources of Hg in this coastal region. Using the 210Pb dating technique, the historical changes in the concentrations and influxes of Hg in the last 100 years were also investigated. The variations in Hg influxes in sediment cores obviously correlate with the economic development and urbanization that has occurred the PRD region, especially in the last three decades. © 2010 Elsevier Ltd. All rights reserved.


Huang Y.Z.,Agro Environmental Protection Institute | Zhong M.,CAS Research Center for Eco Environmental Sciences
Atmospheric Environment | Year: 2015

The open top chamber (OTC) method was used in combination with real-time quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) techniques in the wheat field to study the influence of different levels of O3 concentrations (ambient air filtered by activated carbons, 40ppb, 80ppb and 120ppb) on the quantity and community structure of methanotrophic bacteria. O3 stress can influence the potential methane oxidation rate (PMOR) and potential methane production rate (PMPR) in the farmland soil. O3 treatment of 40ppb improved significantly the 16S rRNA gene copy number in the total methanotrophic bacteria pmoA, and type I and type II methanotrophic bacteria in the soil depth of 0-20cm. When the O3 concentration reached 120ppb, the 16S rRNA gene copy number in the total methanotrophic bacteria pmoA and type I methanotrophic bacteria decreased significantly as compared to the control treatment in 10-20cm layer. The 16s rRNA gene copy number of total methanotrophic bacteria pmoA and type I and type II methanotrophic bacteria were influenced by different O3 concentration and soil depth. The T-RFLP analysis indicated that O3 stress influenced significantly the community structure of the methanotrophic bacteria in soil, causing potential threat to the diversity of methanotrophic bacteria. It seems to imply that the rise of O3 concentration could produce an impact on the carbon cycling and the methane emission of the wheat field soil by changing the community structure and diversity of methanotrophic bacteria, which then influences the global climate change. © 2015 Elsevier Ltd.


Lu Y.,CAS Research Center for Eco Environmental Sciences | Fu B.,CAS Research Center for Eco Environmental Sciences | Feng X.,CAS Research Center for Eco Environmental Sciences | Zeng Y.,CAS Institute of Remote Sensing Applications | And 4 more authors.
PLoS ONE | Year: 2012

As one of the key tools for regulating human-ecosystem relations, environmental conservation policies can promote ecological rehabilitation across a variety of spatiotemporal scales. However, quantifying the ecological effects of such policies at the regional level is difficult. A case study was conducted at the regional level in the ecologically vulnerable region of the Loess Plateau, China, through the use of several methods including the Universal Soil Loss Equation (USLE), hydrological modeling and multivariate analysis. An assessment of the changes over the period of 2000-2008 in four key ecosystem services was undertaken to determine the effects of the Chinese government's ecological rehabilitation initiatives implemented in 1999. These ecosystem services included water regulation, soil conservation, carbon sequestration and grain production. Significant conversions of farmland to woodland and grassland were found to have resulted in enhanced soil conservation and carbon sequestration, but decreased regional water yield under a warming and drying climate trend. The total grain production increased in spite of a significant decline in farmland acreage. These trends have been attributed to the strong socioeconomic incentives embedded in the ecological rehabilitation policy. Although some positive policy results have been achieved over the last decade, large uncertainty remains regarding long-term policy effects on the sustainability of ecological rehabilitation performance and ecosystem service enhancement. To reduce such uncertainty, this study calls for an adaptive management approach to regional ecological rehabilitation policy to be adopted, with a focus on the dynamic interactions between people and their environments in a changing world. © 2012 Lü et al.


Huang H.,CAS Research Center for Eco Environmental Sciences | Zhang S.,CAS Research Center for Eco Environmental Sciences | Christie P.,Agri Food and Biosciences Institute of Northern Ireland | Wang S.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Environmental Science and Technology | Year: 2010

Deca-bromodiphenyl ether (BDE-209) is the major component of the commercial deca-BDE flame retardant. There is increasing concern over BDE-209 due to its increasing occurrence in the environment and in humans. In this study the behavior of BDE-209 in the soil-plant system was investigated. Accumulation of BDE-209 was observed in the roots and shoots of all the six plant species examined, namely ryegrass, alfalfa, pumpkin, summer squash, maize, and radish. Root uptake of BDE-209 was positively correlated with root lipid content (P < 0.001, R2 ) 0.81). The translocation factor (TF, Cshoot/C root) of BDE-209 was inversely related to its concentration in roots. Nineteen lower brominated (di- to nona-) PBDEs were detected in the soil and plant samples and five hydroxylated congeners were detected in the plant samples, indicating debromination and hydroxylation of BDE-209 in the soil-plant system. Evidence of a relatively higher proportion of penta- through di-BDE congeners in plant tissues than in the soil indicates that there is further debromination of PBDEs within plants or low brominated PBDEs are more readily taken up by plants. A significant negative correlation between the residual BDE-209 concentration in soil and the soil microbial biomass measured as the total phospholipid fatty acids (PLFAs) (P <0.05, R2)0.74) suggests that microbial metabolism and degradation contribute to BDE-209 dissipation in soil. These results provide important information about the behavior of BDE-209 in the soilplant system. © 2010 American Chemical Society.


Wang J.,CAS Nanjing Institute of Geography and Limnology | Wang J.,CAS Research Center for Eco Environmental Sciences | Soininen J.,University of Helsinki | He J.,CAS Research Center for Eco Environmental Sciences | Shen J.,CAS Nanjing Institute of Geography and Limnology
Environmental Microbiology Reports | Year: 2012

Although phylogenetic approaches are useful for providing insights into the processes underlying biodiversity patterns, the studies of microbial phylogenetic relatedness are rare, especially for elevational gradients. Using high-throughput pyrosequencing, we examined the biodiversity patterns for biofilm bacterial communities that were scraped from stream stones along an elevational gradient from 1820 to 4050m in China. The patterns of bacterial species richness and phylogenetic diversity were hollow towards higher elevations. The bacterial communities consisted of closer relatives than expected and displayed increasing terminal phylogenetic clustering towards mountain top. The increasing phylogenetic clustering with elevation contrasts reports for macroorganisms that revealed phylogenetic overdispersion at low or intermediate elevations. Because water temperature showed the strongest correlation with phylogenetic relatedness (r 2=0.516), the elevational pattern in the bacterial phylogenetic structure indicated that environmental filtering possibly due to lower temperature or more frequent temperature fluctuations increased towards higher elevations. Evidence supporting the environmental filtering on bacteria was also reflected by the orderly succession in the relative abundance of different bacterial phyla along the elevational gradient and in the high evenness of bacterial taxa at higher elevations. Overall, our results indicated that ecological processes possibly related to temperature may play a dominant role in structuring bacterial biodiversity along the elevational gradient. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.


Chen H.-M.,National Cheng Kung University | Zhu B.-Z.,CAS Research Center for Eco Environmental Sciences | Chen R.-J.,National Cheng Kung University | Wang B.-J.,National Cheng Kung University | And 2 more authors.
PLoS ONE | Year: 2014

Pentachlorophenol (PCP) has been used extensively as a biocide and a wood preservative and has been reported to be immunosuppressive in rodents and humans. Tetrachlorohydroquinone (TCHQ) is a major metabolite of PCP. TCHQ has been identified as the main cause of PCP-induced genotoxicity due to reactive oxidant stress (ROS). However, the precise mechanisms associated with the immunotoxic effects of PCP and TCHQ remain unclear. The aim of this study was to examine the effects of PCP and TCHQ on the induction of ROS and injury to primary mouse splenocytes. Our results shown that TCHQ was more toxic than PCP and that a high dose of TCHQ led to necrotic cell death of the splenocytes through induction of massive and sudden ROS and prolonged ROS-triggered ERK activation. Inhibition of ROS production by N-acetyl-cysteine (NAC) partially restored the mitochondrial membrane potential, inhibited ERK activity, elevated caspase-3 activity and PARP cleavage, and, eventually, switched the TCHQ-induced necrosis to apoptosis. We suggest that prolonged ERK activation is essential for TCHQ-induced necrosis, and that ROS play a pivotal role in the different TCHQ-induced cell death mechanisms. © 2014 Chen et al.


Qiang Z.,CAS Research Center for Eco Environmental Sciences | Dong H.,CAS Research Center for Eco Environmental Sciences | Zhu B.,CAS Research Center for Eco Environmental Sciences | Qu J.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemosphere | Year: 2013

The removal of six endocrine-disrupting chemicals (EDCs), including estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethinyl estradiol (EE2), bisphenol A (BPA) and 4-nonylphenol (NP), was investigated in 20 rural wastewater treatment facilities (WWTFs) located in a county of Zhejiang Province, China. These WWTFs adopted one of the four treatment processes: activated sludge (AS), constructed wetland (CW), stabilization pond (SP), and micro-power biofilm reactor (MP). Results indicate that all the six EDCs were detected in wastewater samples with NP showing a maximum detection frequency (97%) and a maximum influent concentration (5002ngL-1). After biological treatment, the concentrations of E2, E3 and NP decreased remarkably, while E1, EE2 and BPA exhibited varying removal efficiencies that depended on the specific treatment process and sampling season. In general, the centralized AS process outperformed those decentralized processes (i.e., CW, SP and MP) and a higher removal of E1, EE2, NP and BPA in the AS process was observed in summer (>70%) than in winter. Among the three decentralized processes, the removal of EDCs in the SP process was limited, especially for E1, EE2 and BPA (18-46%) in winter. Due to an incomplete removal, the total concentration of target EDCs increased obviously in the mixing and downstream sections of a local river receiving the effluent from a typical WWTF (practicing AS). This study reveals that the design and operation of rural WWTFs should be optimized if an effective removal of EDCs is to be achieved. © 2013 Elsevier Ltd.


Jiang Y.,CAS Research Center for Eco Environmental Sciences | Li X.,CAS Research Center for Eco Environmental Sciences | Huang C.,Wuhan University
Expert Systems with Applications | Year: 2013

Parameter estimation for hydrological models is a challenging task, which has received significant attention by the scientific community. This paper presents a master-slave swarms shuffling evolution algorithm based on self-adaptive particle swarm optimization (MSSE-SPSO), which combines a particle swarm optimization with self-adaptive, hierarchical and multi-swarms shuffling evolution strategies. By comparison with particle swarm optimization (PSO) and a master-slave swarms shuffling evolution algorithm based on particle swarm optimization (MSSE-PSO), MSSE-SPSO is also applied to identify HIMS hydrological model to demonstrate the feasibility of calibrating hydrological model. The results show that MSSE-SPSO remarkably improves the calculation accuracy and is an effective approach to calibrate hydrological model. © 2012 Elsevier Ltd. All rights reserved.


Wang H.,University of Massachusetts Amherst | Kou X.,University of Delaware | Pei Z.,CAS Research Center for Eco Environmental Sciences | Xiao J.Q.,University of Delaware | And 2 more authors.
Nanotoxicology | Year: 2011

To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe3O 4) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe3O4 NPs often induced more oxidative stress than Fe3O4 bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe3O4 NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l-1 Fe3O 4 NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe3O4 NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe3O4 NPs was not significantly increased compared to that in the control shoots. © 2011 Informa UK, Ltd.


Shen Q.,University of South Australia | Shen Q.,CAS Research Center for Eco Environmental Sciences | Zhang W.,University of South Australia | Hao Z.,CAS Research Center for Eco Environmental Sciences | Zou L.,University of South Australia
Chemical Engineering Journal | Year: 2010

A series of TiO2-xNx/Beta composite samples were prepared by coating the nitrogen-doped titania on the Beta zeolite using a simple sol-gel method. Samples were characterized by nitrogen adsorption-desorption, XRD, TEM, UV-vis, XPS and FTIR techniques. The photocatalytic activities were evaluated by the degradation of methylene blue under visible light irradiation. The synergistic effect between absorption and photocatalysis of the TiO2-xNx/Beta composite materials was found in terms of methylene blue removal efficiency under visible light irradiation, since the assisting adsorption ability from H-Beta zeolite could supply a concentrated pollutant environment around titania active sites. The highest photocatalytic efficiency was obtained on the 10% TiO2-xNx-coated composite sample, which was probably due to the better dispersion of titania on the support. Furthermore, the TiO2-xNx/Beta-10% catalyst was consistent to be the most efficient composite material tested for the photocatalytic degradation of methylene blue even in different pH environment. © 2010 Elsevier B.V.


Koken M.,Middle East Technical University | Constantinescu G.,University of Iowa | Blanckaert K.,CAS Research Center for Eco Environmental Sciences
Journal of Geophysical Research: Earth Surface | Year: 2013

Sharply curved open channel flow with a flat bed is investigated with eddy-resolving numerical simulations that complement laboratory experiments. The focus is on the role of coherent flow structures, how these structures contribute to shear stresses and the capacity of the flow to pick up sediment at the boundaries, and on changes resulting from increasing the Reynolds number between typical values for laboratory model studies and for field conditions. In sharply curved bends, secondary flow leads to a transverse component of the bed shear stress that is of comparable magnitude as the streamwise component. Just downstream of the bend entrance, the locus of highest velocities migrates outward and separates from the inner bank. A highly energetic thin shear layer containing large-scale eddies develops at the interface between the core of high streamwise velocities and the retarded fluid moving close to the inner bank. Highly energetic Streamwise-Oriented Vortices (SOVs) develop in the zone of retarded flow. Turbulence, the boundary shear stress, and the sediment pickup capacity are considerably increased by the SOVs and the large-scale eddies inside the shear layer. These large-scale turbulent structures are amplified and become more coherent with increasing Reynolds number. The results indicate that flow processes in scaled laboratory flumes and natural rivers are qualitatively similar, although some quantitative Reynolds-number-induced scale effects exist. The paper also discusses application of several improved methods to estimate mean sediment pickup rates for flow in sharply curved bends. Such methods try to account in an approximate way for the effects of large-scale turbulence in numerical simulations that do not resolve these structures. Key Points Reynolds number affects coherent structures and boundary stresses Streamwise oriented vortical cells affect distribution of boundary stress Sediment entrainment is underpredicted if effect of large eddies is neglected ©2013. American Geophysical Union. All Rights Reserved.


Zhao F.-J.,Nanjing Agricultural University | Zhao F.-J.,Rothamsted Research | Moore K.L.,University of Oxford | Lombi E.,University of South Australia | And 2 more authors.
Trends in Plant Science | Year: 2014

To maintain cellular homeostasis, concentrations, chemical speciation, and localization of mineral nutrients and toxic trace elements need to be regulated. Imaging the cellular and subcellular localization of elements and measuring their in situ chemical speciation are challenging tasks that can be undertaken using synchrotron-based techniques, such as X-ray fluorescence and X-ray absorption spectrometry, and mass spectrometry-based techniques, such as secondary ion mass spectrometry and laser-ablation inductively coupled plasma mass spectrometry. We review the advantages and limitations of these techniques, and discuss examples of their applications, which have revealed highly heterogeneous distribution patterns of elements in different cell types, often varying in chemical speciation. Combining these techniques with molecular genetic approaches can unravel functions of genes involved in element homeostasis. © 2013 Elsevier Ltd.


He G.,CAS Research Center for Eco Environmental Sciences | Zhang L.,Renmin University of China | Mol A.P.J.,Wageningen University | Wang T.,CAS Research Center for Eco Environmental Sciences | Lu Y.,CAS Research Center for Eco Environmental Sciences
Environmental Pollution | Year: 2014

In China, rural chemical SMEs are often believed to still largely operate below the sustainability radar. This paper investigates to what extent and how chemical SMEs are already experiencing pressure to improve their environmental performance, using an in-depth case study in Jasmine County, Hebei province. The results show that local residents had rather low trust in the environmental improvement promises made by the enterprises and the local government, and disagreed with the proposed improvement plans. Although the power of local residents to influence decision making remained limited, the chemical SMEs started to feel increasing pressures to clean up their business, from governments, local communities and civil society, and international value chain stakeholders. Notwithstanding these mounting pressures chemical SME's environmental behavior and performance has not changed radically for the better. The strong economic ties between local county governments and chemical SMEs continue to be a major barrier for stringent environmental regulation. © 2013 Elsevier Ltd. All rights reserved.


Liu Y.,CAS Research Center for Eco Environmental Sciences | Fu B.,CAS Research Center for Eco Environmental Sciences | Lu Y.,CAS Research Center for Eco Environmental Sciences | Wang Z.,California State University, Fresno | Gao G.,CAS Research Center for Eco Environmental Sciences
Geomorphology | Year: 2012

Recent changes in hydrological processes and soil erosion in the Loess Plateau, China, are immediate responses to cropland abandonment for revegetation, which lead to a long-term decrease in runoff generation and soil erosion. However, detailed hydrological responses and soil erosion changes have not been clearly evaluated. In this study, two issues were focused on the plot scale. The first issue relates to changes in vegetation cover and soil properties during the early stages of revegetation. Given the occurrence of soil compaction, it was hypothesized that runoff increased during this period and the soil erosion did not significantly decline, even though vegetation increased. The second issue is the effect of scale on runoff and soil erosion. Three plot groups of three vegetation types and two restoration stages were established for comparative experiments. The results from these experiments confirmed that the soil compaction occurred during revegetation in this region. Greater runoff was produced in plot group that experienced both a longer restoration time and with higher vegetation cover (such as Groups 2 and 3 in this study) than that with a shorter restoration time and lower vegetation cover (Group 1). In addition, the total soil loss rates of all plot groups were rather low and did not significantly differ from each other. This indicates that a reduction in runoff generation and soil erosion, as a result of revegetation, was limited in the early stages of restoration following the cropland abandonment. With increasing plot area, the runoff coefficient decreased for the plot group with a longer revegetation time (Groups 2 and 3), but gently increased for the one with a shorter restoration time (Group 1). In Groups 2 and 3, soil loss rate decreased when plot area enlarged. In Group 1, it decreased before a plot area threshold of 18m2 was exceeded. However, the increase occurred when plot area crossed the threshold value. In conclusion, the high vegetation cover alone did not lead to reduction in the runoff coefficient during the early stages of revegetation. When evaluating hydrological and soil erosion responses to revegetation, the soil compaction processes should be considered. Additionally, the effect of scale on runoff and soil erosion was found to be dependent on restoration extent, and thus on restoration time. © 2011 Elsevier B.V.


Fu B.,CAS Research Center for Eco Environmental Sciences | Liu Y.,CAS Research Center for Eco Environmental Sciences | Lu Y.,CAS Research Center for Eco Environmental Sciences | He C.,Western Michigan University | And 2 more authors.
Ecological Complexity | Year: 2011

Soil erosion in terrestrial ecosystems, as an important global environmental problem, significantly impacts on environmental quality and social economy. By protecting soil from wind and water erosion, terrestrial ecosystems supply human beings with soil erosion control service, one of the fundamental ecosystem services that ensure human welfare. The Loess Plateau was one of the regions in the world that suffered from severe soil erosion. In the past decades, restoration projects were implemented to improve soil erosion control in the region. The Grain-to-Green project, converting slope croplands into forest or grasslands, launched in 1999 was the most massive one. It is needed to assess the change of soil erosion control service brought about by the project. This study evaluated the land cover changes from 2000 to 2008 by satellite image interpretation. Universal Soil Loss Equation (USLE) was employed for the soil erosion control assessment for the same period with localized parameters. Soil retention calculated as potential soil erosion (erosion without vegetation cover) minus actual soil erosion was applied as indicator for soil erosion control service. The results indicate that ecosystem soil erosion control service has been improved from 2000 to 2008 as a result of vegetation restoration. Average soil retention rate (the ratio of soil retention to potential soil loss in percentage) was up to 63.3% during 2000-2008. Soil loss rate in 34% of the entire plateau decreased, 48% unchanged and 18% slightly increased. Areas suffering from intense erosion shrank and light erosion areas expanded. Zones with slope gradient of 8°-35° were the main contribution area of soil loss. On average, these zones produced 82% of the total soil loss with 45.5% of the total area in the Loess Plateau. Correspondingly, soil erosion control capacity was significantly improved in these zones. Soil loss rate decreased from 5000tkm-2yr-1 to 3600tkm-2yr-1, 6900tkm-2yr-1 to 4700tkm-2yr-1, and 8500tkm-2yr-1 to 5500tkm-2yr-1 in the zones with slope gradient of 8°-15°, 15°-25°, and 25°-35° respectively. However, the mean soil erosion rate in areas with slope gradient over 8° was still larger than 3600tkm-2yr-1, which is far beyond the tolerable erosion rate of 1000tkm-2yr-1. Thus, soil erosion is still one of the top environmental problems that need more ecological restoration efforts. © 2011 Elsevier B.V.


Zhang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Tianjin Research Institute for Water Transport Engineering | Chen W.,CAS Research Center for Eco Environmental Sciences | Ma C.,Tianjin Research Institute for Water Transport Engineering | Zhan S.,Tianjin Research Institute for Water Transport Engineering
Atmospheric Environment | Year: 2012

Coal particles emission could cause serious air pollution in coal production region and transport region. In coal mining industry, large amounts of water are regularly spayed to coal piles to prevent dust emission from the coal particles. The mechanism behind this measure is to manage the threshold friction velocity, which is an important parameter in controlling wind erosion and dust emission. Bagnold has developed a threshold friction velocity model for soil particles. However, the Bagnold model cannot be applied directly to coal particles as coal particles are quite different from soils in physical and chemical properties. We studied and modeled threshold friction velocity of coal particles under different humidities by using a wind tunnel. Results showed that the effects of humidity on coal particles' threshold friction velocity are related to the hydrophilic effect and adhesive effect. Bagnold model can be corrected by two new parameter items which explained the two effects. The new model, agreed well with wind tunnel measurements for coal particles with different size categories. Despite the fact the new model was developed for coal particles, its physical basis may allow the model application to other wind susceptible particles. © 2012 Elsevier Ltd.


Xu Y.D.,CAS Research Center for Eco Environmental Sciences | Fu B.J.,CAS Research Center for Eco Environmental Sciences | He C.S.,Western Michigan University | Gao G.Y.,CAS Research Center for Eco Environmental Sciences
Hydrology and Earth System Sciences | Year: 2012

The spatial discretization of watersheds is an indispensable procedure for representing landscape variations in eco-hydrological research, representing the contrast between reality and data-supported models. When discretizing a watershed, it is important to construct a scheme of a moderate number of discretized factors while adequately considering the actual eco-hydrological processes, especially in regions with unique eco-hydrological features and intense human activities. Because of their special lithological and pedologic characteristics and widespread man-made vegetation, discretization of watersheds in the Loess Plateau in Northern China is a challenge. In order to simulate the rainfall-runoff process, a watershed in the Loess Plateau, referred as Ansai, was spatially discretized into new units called land type units. These land type units were delineated under a scheme of factors including land use, vegetation condition, soil type and slope. Instead of using units delineated by overlaying land use and soil maps, the land type units were used in the Soil and Water Assessment Tool (SWAT). Curve numbers were assigned and adjusted to simulate runoff, using the US Natural Resources Conservation Service (NRCS) curve number method. The results of the runoff simulation better matched actual observations. Compared to the results that used the original units, the coefficient of determination (R2) and the Nash-Sutcliffe coefficient (ENS) for monthly flow simulation increased from 0.655-0.713 and 0.271-0.550 to 0.733-0.745 and 0.649-0.703, respectively. This method of delineating into land type units is an easy operation and suitable approach for eco-hydrological studies in the Chinese Loess Plateau and other similar regions. It can be further applied in soil erosion simulation and the eco-hydrological assessment of re-vegetation. © Author(s) 2012.


He G.,CAS Research Center for Eco Environmental Sciences | Bluemling B.,Wageningen University | Mol A.P.J.,Wageningen University | Zhang L.,Renmin University of China | Lu Y.,CAS Research Center for Eco Environmental Sciences
Energy Policy | Year: 2013

Under the dual pressures of an energy crisis and rising greenhouse gas emissions, biomass energy development and utilisation has become part of the national energy strategy in China. The last decade has witnessed a strong promotion of both centralised and decentralised bio-energy systems in rural China. The government seems to have a strong preference for centralised (village-based) bio-energy systems in recent years. However, these government-driven systems have not worked without difficulties, particularly regarding economic and technological viability and maintenance. Studies on the advantages and disadvantages of decentralised and centralised bio-energy systems are rare. This study aims to shed light on the performances of these two systems in terms of social, economic and environmental effects. Through interviewing local officials and village leaders and surveying farmers in 12 villages in Shandong Province, it was found that bio-energy systems should be selected based on the local circumstances. The diversity of the local natural, economic and social situations determines the size, place, technology and organisational model of the bio-energy system. © 2013 Elsevier Ltd.


Shi Y.,CAS Research Center for Eco Environmental Sciences | Zhang N.,Environmental Monitoring Central Station of Gansu Province | Gao J.,Beijing Institute of Technology | Li X.,Beijing Institute of Technology | Cai Y.,CAS Research Center for Eco Environmental Sciences
Atmospheric Environment | Year: 2011

Perchlorate is regarded as a new emerging persistent inorganic environmental contaminant. It can result in important neurodevelopmental deficits and goiter in infants and children because of its inhibition of iodine uptake into the thyroid tissue. Furthermore, its presence in the human body can cause improper regulation of metabolism for adults. It is often used as ingredient in the production of fireworks. So fireworks display may influence the perchlorate levels in atmospheric particulate matter (PM). In this paper perchlorate was determined in air aerosol samples (Inhalable particulate matter (PM10) and larger particulate matter (PM10-100)) collected from two locations (Lanzhou City and Yuzhong County) in Gansu province over a month period (February 1rst to March 4th) during the Spring Festival (February 18th) in 2007 in order to study the effect of fireworks display on perchlorate in air aerosol. The results showed that different concentrations of perchlorate were detected in almost all samples, ranging from


Zhang D.,CAS Research Center for Eco Environmental Sciences | Shen H.,CAS Dalian Institute of Chemical Physics | Li G.,CAS Dalian Institute of Chemical Physics | Zhao B.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Analytical Chemistry | Year: 2012

Fluorescence anisotropy (FA) is a homogeneous, ratiometric, and real-time analytical technology. By selective labeling of a guanine (G)-quadruplex motif with tetramethylrhodamine (TMR), here, it is established that a large reduction in FA response can be specifically associated with the unfolding → folding transition of G-quadruplex structures. On the basis of fluorescence intensity, polarization and lifetime analysis, and molecular docking simulation, the mechanism was found to be that the labeled fluorophore (TMR) can intramolecularly interact with adjacent G bases in an unfolded G-quadruplex motif, which allows for the photoinduced electron transfer (PET) occurring between the fluorophore and G bases, leading to a short fluorescence lifetime. Upon the folding of the motif to form a stable G-quadruplex structure, the intramolecular interactions and the concomitant PET could be eliminated with an increased fluorescence lifetime, leading to a large reduction in the FA response. On the basis of this mechanism, a novel, specific, and sensitive FA approach was developed for the detection of biologically and functionally important G-quadruplex structures. The approach is examined and validated using one normal G-quadruplex motif, five mutants, and six small cations and is potentially applicable to the study of G-quadruplexes at single molecule level, ligand screening, profiling of highly ordered DNA nanostructures, and biosensing. © 2012 American Chemical Society.


He G.,CAS Research Center for Eco Environmental Sciences | Zhang L.,Renmin University of China | Zhang L.,Wageningen University | Lu Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Journal of Hazardous Materials | Year: 2011

Chemical industries, from their very inception, have been controversial due to the high risks they impose on safety of human beings and the environment. Recent decades have witnessed increasing impacts of the accelerating expansion of chemical industries and chemical accidents have become a major contributor to environmental and health risks in China. This calls for the establishment of an effective chemical risk management system, which requires reliable, accurate and comprehensive data in the first place. However, the current chemical accident-related data system is highly fragmented and incomplete, as different responsible authorities adopt different data collection standards and procedures for different purposes. In building a more comprehensive, integrated and effective information system, this article: (i) reviews and assesses the existing data sources and data management, (ii) analyzes data on 976 recorded major hazardous chemical accidents in China over the last 40 years, and (iii) identifies the improvements required for developing integrated risk management in China. © 2011 Elsevier B.V.


Su C.-H.,CAS Research Center for Eco Environmental Sciences | Fu B.-J.,CAS Research Center for Eco Environmental Sciences | He C.-S.,Western Michigan University | Lu Y.-H.,CAS Research Center for Eco Environmental Sciences
Acta Oecologica | Year: 2012

The concept of 'ecosystem service' provides cohesive views on mechanisms by which nature contributes to human well-being. Fast social and economic development calls for research on interactions between human and natural systems. We took the Yanhe Watershed as our study area, and valued the variation of ecosystem services and human activities of 2000 and 2008. Five ecosystem services were selected i.e. net primary production (NPP), carbon sequestration and oxygen production (CSOP), water conservation, soil conservation, and grain production. Human activity was represented by a composite human activity index (HAI) that integrates human population density, farmland ratio, influence of residential sites and road network. Analysis results of the five ecosystem services and human activity (HAI) are as follows: (i) NPP, CSOP, water conservation, and soil conservation increased from 2000 to 2008, while grain production declined. HAI decreased from 2000 to 2008. Spatially, NPP, CSOP, and water conservation in 2000 and 2008 roughly demonstrated a pattern of decline from south to north, while grain production shows an endocentric increasing spatial pattern. Soil conservation showed a spatial pattern of high in the south and low in the north in 2000 and a different pattern of high in the west and low in the east in 2008 respectively. HAI is proportional to the administrative level and economic development. Variation of NPP/CSOP between 2000 and 2008 show an increasing spatial pattern from northwest to southeast. In contrast, the variation of soil conservation shows an increasing pattern from southeast to northwest. Variation of water conservation shows a fanning out decreasing pattern. Variation of grain production doesn't show conspicuous spatial pattern. (ii) Variation of water conservation and of soil conservation is significantly positively correlated at 0.01 level. Both variations of water conservation and soil conservation are negatively correlated with variation of HAI at 0.01 level. Variations of NPP/CSOP are negatively correlated with variations of soil conservation and grain production at 0.05 level. (iii) Strong tradeoffs exist between regulation services and provision service, while synergies exist within regulation services. Driving effect of human activities on ecosystem services and tradeoffs and synergies among ecosystem service are also discussed. © 2011 Elsevier Masson SAS.


Xiu F.-R.,Fujian University of Technology | Xiu F.-R.,Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling | Zhang F.-S.,CAS Research Center for Eco Environmental Sciences
Journal of Hazardous Materials | Year: 2012

In this work, an effective and size-controlled process for preparing Cu2O nanomaterials from waste PCBs by supercritical water (SCW) combined with electrokinetic (EK) technique was developed. SCW was used for the pretreatment of waste PCBs, and highly uniform and monodisperse Cu2O nanoparticles with different sizes were prepared successfully from waste PCBs in EK process. Cu2O nanoparticles with average sizes of 5, 11, 25 and 40nm could be prepared in the presence of nanoparticles stabilizer (PVP) with the concentrations of 40, 30, 20 and 10g/L, respectively. The average size of Cu2O nanoparticles decreased from 49.5 to 18.2nm when current density increased from 10 to 20mA/cm2, and the size uniformity of nanoparticles was improved distinctly at a higher current density. The size of Cu2O nanoparticles increased with the increase of EK time, and agglomeration of particles was observed after 8h EK reaction. Up to 90wt% of the Cu in waste PCBs could be recovered as Cu2O nanoparticles under optimized condition. It is believed that the process developed in this study is simple and practical for size-controlled preparation of nanomaterials from waste PCBs or other Cu-rich solid wastes. © 2012 Elsevier B.V.


Ren J.-M.,CAS Research Center for Eco Environmental Sciences | Ren J.-M.,Appraisal Center for Environment and Engineering | Zhang L.,Renmin University of China | Wang R.-S.,CAS Research Center for Eco Environmental Sciences
Ecological Complexity | Year: 2010

Recent years have seen increasing demand for wider application of strategic environmental assessment (SEA), especially SEA of major policies, as a powerful instrument to safeguard the environment during the rapid industrialization and urbanization in China. Debates on SEA are concentrated on its feasibility and effective implementation in practice. This study applies Emergy analysis within the framework of social-economic-natural complex eco-system theory to overcome the limitations of methods used for assessing regional sustainability so far. This established model is tested in the case of Chinese paper industry to assess the sustainability of 5 policy scenarios. The results show that Emergy-based Indices (EbI) are more effective to measure the sustainability of industry complex ecosystem, thus EbI approach is very useful in SEAs on policy scenarios of a given complex ecosystem. © 2010 Elsevier B.V.