Zhao X.,Beijing Normal University |
Shen Z.Y.,Beijing Normal University |
Xiong M.,Changjiang River Scientific Research Institute |
Qi J.,Beijing Municipal Research Institute of Environmental Protection
International Journal of Environmental Science and Technology | Year: 2011
In this study, key uncertainty sources analysis was undertaken for a dynamic water model using a First order error analysis method. First, a dynamic water quality model for the Three Gorges Reservoir Regions was established using data after impoundment by the environmental fluid dynamics code model package. Model calibration and verification were then conducted using measured data collected during 2004 and 2006. Four statistical indices were employed to assess the modeling efficiency. The results indicated that the model simulated the variables well, with most relative error being less than 25 %. Next, input and parameter uncertainty analysis were conducted for ammonia nitrogen, nitrate nitrogen, total nitrogen, and dissolved oxygen at 3 grid cells located in the upper, middle and downstream portions of the research area. For the nitrogen related variables, input from Zhutuo Station, the Jialingjiang River, and the Wujiang River were the main sources of uncertainty. Point and nonpoint sources also accounted for a large ratio of uncertainty. Moreover, nitrification contributed some uncertainty to the estimated ammonia nitrogen and nitrate nitrogen. However, reaeration was found to be a key source of uncertainty for dissolved oxygen, especially at the middle and downstream reaches. The analysis conducted in this study gives a quantitative assessment for uncertainty sources of each variable, and provides guidance for further pollutant loading reduction in the Three Gorge Reservoir Region. © IRSEN, CEERS, IAU.
Zhang L.,Beijing Normal University |
Yang Z.,Beijing Normal University |
Liang J.,Beijing Municipal Research Institute of Environmental Protection |
Cai Y.,Dalhousie University
Energies | Year: 2011
With support of GIS tools and Theil index, the spatial variance of urban energy consumption in China was discussed in this paper through the parallel comparison and quantitative analysis of the 30 provincial capital cities of mainland China in 2005, in terms of scale, efficiency and structure. The indicators associated with urban energy consumption show large spatial variance across regions, possibly due to diversities of geographic features, economic development levels and local energy source availability in China. In absolute terms, cities with the highest total energy consumption are mostly distributed in economic-developed regions as Beijing-Tianjin-Tangshan Area, Yangtze River Delta and Pearl River Delta of China, however, the per capita urban energy use is significantly higher in the Mid-and-Western regions. With regard to the energy mix, coal still plays the dominant role and cities in Mid-and-Western regions rely more on coal. In contrast, high quality energy carrier as electricity and oils are more used in southeast coastal zone and northern developed areas. The energy intensive cities are mainly located in the northwest, while the cities with higher efficiency are in southeast areas. The large spatial variance of urban energy consumption was also verified by the Theil indices. Considering the Chinese economy-zones of East, Middle and West, the within-group inequalities are the main factor contributing to overall difference, e.g., the Theil index for per capita energy consumption of within-group is 0.18, much higher than that of between group (0.07), and the same applies to other indicators. In light of the spatial variance of urban energy consumptions in China, therefore, regionalized and type-based management of urban energy systems is badly needed to effectively address the ongoing energy strategies and targets. © 2010 by the authors.
Ji L.,Lanzhou University |
Zhou L.,Lanzhou University |
Bai X.,Tsinghua University |
Shao Y.,Lanzhou University |
And 4 more authors.
Journal of Materials Chemistry | Year: 2012
A one-step thermal decomposition strategy, in which a novel reductant participated, was developed to prepare superparamagnetic nearly cubic monodisperse Fe 3O 4 nanoparticles loaded on multiwall carbon nanotubes (MWCNTs/Fe 3O 4). Subsequently, the as-prepared MWCNTs/Fe 3O 4 nanocomposites were modified with 3-aminopropyltriethoxysilane (APTS) (MWCNTs/Fe 3O 4-NH 2). The materials were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and the BET surface area method. The results indicated that superparamagnetic Fe 3O 4 nanoparticles were successfully loaded onto the surface of the MWCNTs, and APTS was also modified on the MWCNTs/Fe 3O 4 magnetic nanocomposites. The two as-prepared magnetic nanocomposites were used as adsorbents to remove tetrabromobisphenol A (TBBPA) and Pb(ii) from wastewater. The adsorption kinetics and adsorption isotherms of TBBPA and Pb(ii) on the two as-prepared adsorbents were studied at pH 7.0 and 5.3, respectively. It was revealed that MWCNTs/Fe 3O 4-NH 2 performed better than the MWCNTs/Fe 3O 4 nanocomposites for the adsorption properties of TBBPA and Pb(ii). After adsorption, both adsorbents could be conveniently separated from the media by an external magnetic field within several seconds, and regenerated in 0.1 M NaOH solution. © 2012 The Royal Society of Chemistry.
Gong H.,Tsinghua University |
Yan Z.,Beijing Municipal Research Institute of Environmental Protection |
Liang K.Q.,Beijing Municipal Research Institute of Environmental Protection |
Jin Z.Y.,Tsinghua University |
Wang K.J.,Tsinghua University
Desalination | Year: 2013
The utilization of liquid digestates from centralized biogas plants commonly used in the agricultural sector of China is limited by the high transportation and storage costs resulting from their extremely large volumes. A pilot-scale disk tube-reverse osmosis (DT-RO) system was set up in the biogas plant of a poultry farm to test the efficiency of the concentrating process. This set up was operated for 1. year to optimize the system and evaluate membrane fouling. The liquid digestate volume remarkably decreased by about 25%, with a concentration factor of 4 under an operation pressure of 45. bar to 55. bar. Nutrients and mineral elements were simultaneously accumulated and total nitrogen and total phosphorus increased by 4.2 and 4.4 times, respectively. The total amino acid in the concentrated digestate reached 4.93. g/L. SEM-EDS analysis showed that membrane fouling was an integrated result of inorganic and organic fouling. © 2013 Elsevier B.V.
Zheng M.X.,Tsinghua University |
Wang K.J.,Tsinghua University |
Zuo J.E.,Tsinghua University |
Yan Z.,Beijing Municipal Research Institute of Environmental Protection |
And 2 more authors.
Bioresource Technology | Year: 2012
The hydraulic characteristics of a lab-scale and a full-scale (275m 3) expanded granular sludge bed (EGSB)-type reactor under different organic loading rates varying from 10kgCODm -3d -1 to 45kgCODm -3d -1 were investigated. A modified combined model composed of two completely mixing regions and a plug flow region was sufficient for simulating the flow pattern of a full-scale EGSB-type reactor. Moreover, the outputs fitted the measured tracer distribution results well. The simplified model structure was in very good agreement with the physical structure of a full-scale EGSB-type reactor. The upflow (liquid+gas) velocity, high concentration of granular sludge, and gas hold-up effect may contribute to the generation of dead spaces (maximum of 19.5%). The bed expansion characteristics indicated that the sludge bed of the EGSB-type reactor performed as a suspended bed, in which the bed expansion was controlled between 20% and 30%, rather than the usually considered expanded bed. © 2011 Elsevier Ltd.
Luo J.,CAS Research Center for Eco Environmental Sciences |
Luo J.,Beijing Municipal Research Institute of Environmental Protection |
Lei B.,CAS Research Center for Eco Environmental Sciences |
Ma M.,CAS Research Center for Eco Environmental Sciences |
And 2 more authors.
Water Research | Year: 2011
Assignment of ecological impacts of contamination to specific classes of contaminants is a prerequisite for risk assessment and remediation. In this study, the combination of polarity-based fractionation, two-hybrid yeast bioassay, and chemical analysis were used to evaluate and identify estrogen receptor agonists (ER-agonists) in sediments from Wenyu River, Beijing, China. By bioassay, organic raw sediment extracts could induce significant estrogenicity and the bioassay-derived 17β-estradiol equivalents (EEQs) of raw extracts (EEQraws) ranged from 0.8 to 19.8 ng/g dry weight. By polarity-based fractionation, the raw extracts were separated into three fractions, i.e. non-polar, moderately polar, and polar fractions, which were subjected to bioassay and chemical analysis. The highest estrogenicity was observed in the polar fraction, which accounted for more than 78% of the total. The medium polar fraction contains PAHs and OCPs, and the estrogenic activities in this fraction contributed 3%-12% of the total in raw extract. An estrogenic activity of non-polarity fraction was negligible in compare to other two fractions. By chemical analysis and toxic equivalent calculation, major part of the estrogenicity in polar fraction could be attributed to six natural/synthetic estrogens (16%-63%), i.e. 17β-estradiol, estrone, estriol, 17α-ethynylestradiol, diethylstilbestrol, and β-estradiol-17-valerate, and to nonylphenols (26%-55%). The proposed approach has been successfully used for characterization of ER-agonists in this case study. © 2011 Elsevier Ltd.
Li M.,Water Resources University |
Feng C.,Water Resources University |
Zhang Z.,University of Tsukuba |
Chen R.,University of Tsukuba |
And 3 more authors.
Electrochimica Acta | Year: 2010
Electrochemical reduction of nitrate in an undivided cell was studied in the present experiments. The optimization of the influencing factors on electrochemical reduction of nitrate by response surface methodology (RSM) was also studied. An ideal condition of performing both cathodic reduction of nitrate and anodic oxidation of the formed by-product in the presence of NaCl was achieved in the present experiment. The Box-Behnken design can be employed to develop mathematical models for predicting electrochemical nitrate removal geometry. The removal is sensitive to the current density and time in the present study. The value of R2 > 0.99 for the present mathematical model indicates the high correlation between observed and predicted values. The optimal NaCl dosage, current density and electrolysis time for nitrate removal in the present experiment are 0.47 g L-1, 26.06 mA cm-2, and 111.88 min, respectively, at which the nitrate nitrogen (nitrate-N) and ammonia nitrogen (ammonia-N) concentration in the treated solution are 9.80 and 0 mg L-1, respectively, which will meet the standards for drinking water. © 2010 Elsevier Ltd.
Wang D.,Beijing University of Civil Engineering and Architecture |
Shi X.X.,Beijing University of Civil Engineering and Architecture |
Yin J.Y.,Beijing Municipal Research Institute of Environmental Protection
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2015
Support Vector Machine(SVM) is widely used in the pattern classification and regression analysis, as well as SVM is a kind of artificial intelligent method at present in China. In nature SVM is essentially a kernel method. this paper adapts RBF, linear and Sigmoid kernel separately to establish SVM model for training and predicting the air conditioning hourly load of a bank in summer. At the same time the comparisons among them are produced, the results show that the model based on RBF kernel function holds stronger extensive ability and higher learning capacity. ©, 2015, The editorial office of Transaction of China Electrotechnical Society. All right reserved.
Yu J.,Beijing Municipal Research Institute of Environmental Protection
Advanced Materials Research | Year: 2011
The problem and several restricted factors of agriculture application of sewage sludge are analyzed at home and abroad. Meanwhile, this paper points out that the several restricted factors of agriculture application include mainly: hazardous chemical matters and heavy metal, receptivity of farmers and consumers to the product of sewage sludge, perfect policy and criterion standards, disposing charge of sewage sludge. The several restricted factors of agriculture application should be resolved if sewage sludge is used safely and environment. © (2011) Trans Tech Publications.
Chen Y.,Dezhou University |
Chen Y.,University of Science and Technology Beijing |
Wang K.,Beijing Municipal Research Institute of Environmental Protection |
Wang K.,University of Science and Technology Beijing
Photochemical and Photobiological Sciences | Year: 2013
One new azacrown[N,S,O]-modified metal-free porphyrin derivative, H 2Por-azacrown (1), with the central tetrapyrrole moiety as signaling fluorophore and/or metal ion receptor has been designed, synthesized, and characterized. Addition of Ag+ into this novel metal-free porphyrin compound induces a fluorescence ON-OFF process, while adding Pb2+ leads to absorption/emission-ratiometric signals. Quite interestingly, blue-shift of the Soret band, ratiometric change of Q bands, and dual-signal changes (absorption ratio and fluorescence ON-OFF) associated with the Cu 2+ displacement from the 1-Pb2+ system were observed upon addition of Cu2+. These results render this H2Por-azacrown compound a porphyrin-based multi-responsive optical sensor towards Ag +, Pb2+, and in particular Cu2+ with dual-mode detecting potential. This journal is © The Royal Society of Chemistry and Owner Societies.