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Bao J.,Jiangsu Academy of Environmental Sciences | Fu Y.,Tongji University | Bao Z.,Tongji University
Nanoscale Research Letters | Year: 2013

A thiol-functionalized magnetite/graphene oxide (MGO) hybrid as an adsorbent of Hg2+ was successfully synthesized by a two-step reaction. It exhibited a higher adsorption capacity compared to the bare graphene oxide and MGO due to the combined adsorption of thiol groups and magnetite nanocrystals. Its capacity reached 289.9 mg g-1 in a solution with an initial Hg2+ concentration of 100 mg l-1. After being exchanged with H+, the adsorbent could be reused. The adsorption of Hg2+ by the thiol-functionalized MGO fits well with the Freundlich isotherm model and followed pseudo-second-order kinetics. © 2013 Bao et al.

Zhao Y.,Nanjing University | Zhang J.,Jiangsu Academy of Environmental Sciences | Nielsen C.P.,Harvard University
Atmospheric Chemistry and Physics | Year: 2013

To examine the effects of China's national policies of energy conservation and emission control during 2005-2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissions of anthropogenic SO2, CO, and total primary PM (particulate matter) in 2010 are estimated to have been 89%, 108%, and 87% of those in 2005, respectively, suggesting successful emission control of those species despite fast growth of the economy and energy consumption during the period. The emissions of NOx and CO2, however, are estimated to have increased by 47% and 43%, respectively, indicating that they remain largely determined by the growth of energy use, industrial production, and vehicle populations. Based on application of a Monte-Carlo framework, estimated uncertainties of SO2 and PM emissions increased from 2005 to 2010, resulting mainly from poorly understood average SO2 removal efficiency in flue gas desulfurization (FGD) systems in the power sector, and unclear changes in the penetration levels of dust collectors at industrial sources, respectively. While emission trends determined by bottom-up methods can be generally verified by observations from both ground stations and satellites, clear discrepancies exist for given regions and seasons, indicating a need for more accurate spatial and time distributions of emissions. Limitations of current emission control polices are analyzed based on the estimated emission trends. Compared with control of total PM, there are fewer gains in control of fine particles and carbonaceous aerosols, the PM components most responsible for damages to public health and effects on radiative forcing. A much faster decrease of alkaline base cations in primary PM than that of SO2 may have raised the acidification risks to ecosystems, indicating further control of acid precursors is required. Moreover, with relatively strict controls in developed urban areas, air pollution challenges have been expanding to less-developed neighboring regions. There is a great need in the future for multi-pollutant control strategies that combine recognition of diverse environmental impacts both in urban and rural areas with emission abatement of multiple species in concert. © Author(s) 2013.

Chen F.,Nanjing University of Science and Technology | Hu W.,Jiangsu Academy of Environmental Sciences | Zhong Q.,Nanjing University of Science and Technology
Atmospheric Research | Year: 2013

Real-world vehicle emission factors for PM10 (particulate matter with aerodynamic diameter smaller than 10μm) and particle-phase polycyclic aromatic hydrocarbons (PAHs) from mixed vehicles were quantified in the Fu Gui-shan Tunnel of Nanjing during summer and winter of 2010. Concentrations of PM10 and sixteen particle phase polycyclic aromatic hydrocarbons (PAHs) in the entrance and exit of the tunnel were studied. The results showed that the four most abundant particular phase polycyclic aromatic hydrocarbons (PAHs) of motor vehicle were benzo[ghi]perylene, benzo[k]fluoranthene, benz[a]anthracene and benzo[a]pyrene. The emission factors for PM10 and particle-phase PAHs were 687mgveh-1km-1 and 18.853mgveh-1km-1 in summer, 714mgveh-1km-1 and 20.374mgveh-1km-1 in winter. Higher particle-phase PAH emission factors were found to be associated with a high proportion of diesel-fueled vehicles (DV). The estimated PM10 emission factor of gasoline-fueled vehicles (GV) was 513mgveh-1km-1 and the value for DV was 914mgveh-1km-1, while EFDV of particulate PAH (31.290mgveh-1km-1) was nearly 4 times higher than EFGV (9.310mgveh-1km-1). The five highest emission factors of diesel-fueled vehicles (DV) were benzo[ghi]perylene, benzo[k]fluoranthene, Indeno[1,2,3-cd]pyrene, benz[a]anthracene and benzo[a]pyrene, which was similarly found in the gasoline-fueled vehicles (GV). The sum of these five emission factors accounted for ~69% of the total particle-phase PAH of DV and ~67% of GV. © 2013 Elsevier B.V.

Wang N.-X.,Nanjing University | Li Y.,Jiangsu Academy of Environmental Sciences | Deng X.-H.,CAS Nanjing Institute of Soil Science | Miao A.-J.,Nanjing University | And 2 more authors.
Water Research | Year: 2013

In the present study, the toxicity and bioaccumulation kinetics of arsenate in two green algae Chlamydomonas reinhardtii and Scenedesmus obliquus under phosphate-enriched (+P) and limited (-P) conditions were investigated. P-limitation was found to aggravate arsenate toxicity and S. obliquus was more tolerant than C. reinhardtii. Such phosphate-condition-dependent or algal-species-specific toxicity difference was narrowed when the relative inhibition of cell growth was plotted against intracellular arsenate content instead of its extracellular concentration. The discrepance was further reduced when the intracellular ratio of arsenic to phosphorus was applied. It suggests that both arsenate bioaccumulation and intracellular phosphorus played an important role in arsenate toxicity. On the other hand, arsenate uptake was induced by P-limitation and its variation with ambient arsenate concentration could be well fitted to the Michaelis-Menten model. Arsenate transporters of S. obliquus were found to have a higher affinity but lower capacity than those of C. reinhardtii, which explains its better regulation of arsenate accumulation than the latter species in the toxicity experiment. Further, arsenate depuration was facilitated and more was transformed to arsenite in C. reinhardtii or under -P condition. Intracellular proportion of arsenite was also increased after the algae were transferred from the long-term uptake media to a relatively clean solution in the efflux experiment. Both phenomena imply that algae especially the sensitive species could make physiological adjustments to alleviate the adverse effects of arsenate. Overall, our findings will facilitate the application of algae in arsenate remediation. © 2013 Elsevier Ltd.

Zhao Y.,Nanjing University | Zhang J.,Jiangsu Academy of Environmental Sciences | Nielsen C.P.,Harvard University
Atmospheric Chemistry and Physics | Year: 2014

To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through 2030. The emission control strategies are expected to have more effects than the energy paths on the future emission trends for all the concerned pollutants. As recently promulgated national action plans of air pollution prevention and control (NAPAPPC) are implemented, China's anthropogenic pollutant emissions should decline. For example, the emissions of SO2, NOx, total suspended particles (TSP), PM10, and PM2.5 are estimated to decline 7, 20, 41, 34, and 31% from 2010 to 2030, respectively, in the "best guess" scenario that includes national commitment of energy saving policy and implementation of NAPAPPC. Should the issued/proposed emission standards be fully achieved, a less likely scenario, annual emissions would be further reduced, ranging from 17 (for primary PM2.5) to 29% (for NOx) declines in 2015, and the analogue numbers would be 12 and 24% in 2030. The uncertainties of emission projections result mainly from the uncertain operational conditions of swiftly proliferating air pollutant control devices and lack of detailed information about emission control plans by region. The predicted emission trends by sector and chemical species raise concerns about current pollution control strategies: the potential for emissions abatement in key sectors may be declining due to the near saturation of emission control devices use; risks of ecosystem acidification could rise because emissions of alkaline base cations may be declining faster than those of SO2; and radiative forcing could rise because emissions of positive-forcing carbonaceous aerosols may decline more slowly than those of SO2 emissions and thereby concentrations of negative-forcing sulfate particles. Expanded control of emissions of fine particles and carbonaceous aerosols from small industrial and residential sources is recommended, and a more comprehensive emission control strategy targeting a wider range of pollutants (volatile organic compounds, NH3 and CO, etc.) and taking account of more diverse environmental impacts is also urgently needed. © 2014 Author(s).

Shen G.,Jiangsu Academy of Environmental Sciences | Shen G.,Oak Ridge Institute for Science and Education
Biomass and Bioenergy | Year: 2016

Household biomass and coal use is an important source of PM2.5 emission in China due to low efficient burnings and large consumptions. Primary PM2.5 emissions for different fuels are compared based on a compilation of data from emission measurements of Chinese cookstoves in literature. The burning of pellets had low PM2.5 emissions at 0.42 and 0.18 g MJd -1 for straw and wood pellets, respectively. There would be an emission reduction of about 80% compared to ordinary raw biomass fuel burning for cooking. The average emissions of PM2.5 per useful energy delivered were 0.10 and 0.28 g MJd -1 for anthracite briquette and chunk, but as high as 1.2 and 3.2 g MJd -1 for bituminous briquette and chunk, respectively. Coals burned in the form of briquette may lower PM2.5 emission by 60% compared to the burning of raw chunk. The adoption of improved high efficiency cookstoves would have a comparable reduction in primary emissions compared to a fuel switch. Gas should be promoted for cooking as primary PM2.5 emissions are 1,2 orders of magnitude lower compared to those for solid fuels. More emission measurements and fuel consumption survey are needed to fill data gap and to support interventions of advanced fuel-stove combinations. © 2016 Elsevier Ltd.

Kong Y.,Changzhou University | Li W.,Changzhou University | Wang Z.,Jiangsu Academy of Environmental Sciences | Yao C.,Changzhou University | Tao Y.,Changzhou University
Electrochemistry Communications | Year: 2013

Electrosorption behavior of copper ions was investigated at poly(m-phenylenediamine) (PmPD) paper electrode in relation to development of methodologies for purification of industrial wastewaters. Cu2 + electrosorption process was monitored by in situ conductivity detection. Electrosorption was carried by polarization of a PmPD paper electrode, potentiostatically. The redox states of PmPD varied with different polarization directions, which were verified by FT-IR. The removal mechanism may include electrostatic interaction and chelation between Cu2 + and polarized PmPD. Electrodesorption experiments were carried out to explore possibilities of regeneration of PmPD, and the results indicated that PmPD is a promising material for Cu2 + electrosorption as it remained effective after 10 cycles. © 2012 Elsevier B.V. All rights reserved.

Jiangsu Academy of Environmental Sciences | Date: 2014-04-24

The present disclosure discloses a method for determining ecological risks of heavy metal pollution in sediments of river and lake. The method includes the following steps of: (1) determining concentration levels of heavy metal pollutants at different positions of water body sediments; (2) conducting statistic analysis on distribution characteristics of concentration data of various heavy metal pollutants in the water body sediments; (3) calculating an ecological risk index of a heavy metal pollutant using a formula; (4) calculating a final result of E_(r)^(i); (5) drawing a distribution curve of E_(r)^(i )values; (6) calcualting a total ecological risk comprehensive index HRI caused by various heavy metal pollutants in the evalulated water body, and drawing a cumulative probability distribution curve of HRI values; and (7) analyzing a probability that the total ecological risk comprehensive index HRI of the water body appears at different risk levels with reference to a risk level classification standard.

Jiangsu Academy of Environmental Sciences | Date: 2014-04-24

The present disclosure discloses a method for determining ecological risks of polycyclic aromatic hydrocarbon in a water body. The method may include (1) screening representative species of a water ecological system in a region; (2) obtaining toxicity data of benzoapyrene; (3) calculating benzoapyrene concentration values HC5 of 95% of species in the protected water ecological system; (4) determining types of polycyclic aromatic hydrocarbon pollutants and corresponding environmental concentrations thereof by sampling, and analyzing concentration distribution characteristics of various polycyclic aromatic hydrocarbons; (5) calculating ecological risk quotient values RQi of specific polycyclic aromatic hydrocarbon pollutants; and (6) calculating a total ecological risk quotient value RQt and confirming concrete ecological risks. The method may analyze whether potential risks caused by the polycyclic aromatic hydrocarbon pollutants are acceptable, and determine whether the total level of the ecological risks of the water body needs to be controlled.

Jiangsu Academy of Environmental Sciences | Date: 2015-01-26

The present invention discloses a blade device for the mixing propeller comprises a rocking shaft and a plurality of blade units; the said blade unit is made of flexible material and is installed on the rocking shaft via the fixing groove; the said blade unit consists of a horizontal propelling flexible blade and a vertical uplifting flexible blade whereas the said fixing groove consists of a horizontal section and a vertical section; one end of the said horizontal propelling flexible blade is inserted in the vertical section of the fixing groove while the other end of which is kept free so that it can swing back and forth; one end of the said vertical uplifting flexible blade is inserted in the horizontal section of the fixing groove while the other end of which is kept free so that it can swing back and forth.

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