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Tang W.,CAS Research Center for Eco Environmental Sciences | Zhao Y.,CAS Research Center for Eco Environmental Sciences | Wang C.,CAS Research Center for Eco Environmental Sciences | Shan B.,CAS Research Center for Eco Environmental Sciences | Cui J.,Beijing Sound Environmental Engineering Co.
Ecotoxicology and Environmental Safety | Year: 2013

The Haihe Basin is in an area of high population density and rapid economic development, and is one of the most polluted river basins in China. Examination of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in overlying waters and surface sediments in rivers was conducted in the basin's seven watersheds. Cd concentrations of overlying river waters exceeded Chinese environmental quality standard values for surface water (>0.010. mg/L) at 90% of stations. In surface river sediments, average concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in the basin were 0.364, 13.4, 81.9, 53.3, 435, 27.8, 20.0 and 256. mg/kg, respectively. Cd, Zn and Cu were the most anthropogenically enriched elements, as indicated by enrichment factor (EF) values>1.5; EF values were highest for these metals in the Zi Ya He (ZYH) and Zhang Wei He (ZWH) watersheds. Cd in surface river sediments showed a high potential ecological risk (PER) in the ZYH and ZWH watersheds. The comprehensive PER due to all studied metals was high at many stations, especially in the ZYH and ZWH watersheds. The results indicate that heavy metal contamination in the rivers of the Haihe Basin should be considered when developing basin management strategies for protecting the aquatic environment. © 2013 Elsevier Inc. Source

Tang W.,CAS Research Center for Eco Environmental Sciences | Cui J.,Beijing Sound Environmental Engineering Co. | Shan B.,CAS Research Center for Eco Environmental Sciences | Wang C.,CAS Research Center for Eco Environmental Sciences | Zhang W.,CAS Research Center for Eco Environmental Sciences
PLoS ONE | Year: 2014

The Hai River Basin (HRB) is one of the most polluted river basins in China. The basin suffers from various types of pollutants including heavy metals and nutrients due to a high population density and rapid economic development in this area. We assessed the relationship between heavy metal accumulation by periphyton playing an important role in fluvial food webs and eutrophication in the HRB. The concentrations of the unicellular diatoms (type A), filamentous algae with diatoms (type B), and filamentous algae (type C) varied along the river, with type A dominating upstream, and types B then C increasing in concentration further downstream, and this was consistent with changes in the trophic status of the river. The mean heavy metal concentrations in the type A, B and C organisms were Cr: 18, 18 and 24 mg/kg, respectively, Ni: 9.2, 10 and 12 mg/kg, respectively, Cu: 8.4, 19 and 29 mg/kg, respectively, and Pb: 11, 9.8 and 7.1 mg/kg respectively. The bioconcentration factors showed that the abilities of the organisms to accumulate Cr, Ni and Pb decreased in the order type A, type B, then type C, but their abilities to accumulate Cu increased in that order. The Ni concentration was a good predictor of Cr, Cu and Pb accumulation by all three periphyton types. Our study shows that heavy metal accumulation by periphyton is associated with eutrophication in the rivers in the HRB. © 2014 Tang et al. Source

Zuo X.,Huazhong Agricultural University | Wang L.,Beijing Sound Environmental Engineering Co. | He J.,Huazhong Agricultural University | Li Z.,Huazhong Agricultural University | Yu S.,Tongji University
Desalination | Year: 2014

This study focused on the characterization of SiO2/PVDF anion-exchange membrane (AEM) fouling in electrodialysis for the treatment of polymer-flooding produced wastewater containing suspended solid (SS), anionic polyacrylamide (APAM) and crude oil in Daqing oilfield in China. Scanning electron microscopy (SEM) combined with energy dispersive X-ray (EDX) analysis was used to investigate the membrane surface morphology and examine the chemical composition of the fouled membrane surface. The morphological study showed only a small amount of cake layers located on the external surface of the SiO2/PVDF AEMs fouled by SS and APAM, respectively. Meanwhile, the contaminants adsorbed on the membrane surface and in the membrane pores were relatively more in the presence of crude oil. It was also found that the SiO2/PVDF membranes exhibited better antifouling capacity than PVDF membranes indicated in the membrane fouling behavior and desalination time. EDX analyses revealed that the foulants on the membrane surfaces comprised not only organic substances but also inorganic elements. © 2013 Elsevier B.V. Source

Wu D.,Tongji University | Wu D.,Beijing Sound Environmental Engineering Co. | Wang K.,Beijing Sound Environmental Engineering Co. | Liu Y.,Beijing Sound Environmental Engineering Co. | And 4 more authors.
Chinese Journal of Environmental Engineering | Year: 2013

Two-stage A/O process combining with AS-SMBR and NF treatment systems were adopted to treat the aged-landfill leachate which had a BOD5/NH3-N propotion of 0.13~0.22, and the BOD5/COD was only 0.11. It was necessary to control DO value of biochemical system between 3~4 mg/L, reflux ratio at 400%~500%, and pH value≥7.2 at the same HRT. The index of main contaminant of landfill leachate and the changes of MLSS, pH and SV30 during commissioning were investigated. The results show that the removal rate of ammonia in biochemical system>99%, and average COD removal rate>50%, and the removal rate of COD in NF system≥91%, the concentration of ammonia <8 mg/L, simultaneously, coefficient of recovery was ≥75%, effluent of treatment system could reach the standard of GB16889-2008 completely and meet the needs of upgrading project. Source

Liu X.S.,Ocean University of China | Bai J.,Ocean University of China | Sun J.J.,Beijing Sound Environmental Engineering Co. | Hou R.,Ocean University of China | Zhao Y.G.,Ocean University of China
Applied Mechanics and Materials | Year: 2014

The denitrification and its influencing factors were studied in reed, suaeda heteroptera and reed degraded wetland. PDR were similar in reed and suaeda heteroptera wetland; primary influencing factors were temperature, nitrate and TOC. pN2O, N2O/ (N2O + N2) were less in reed wetland than that in suaeda heteroptera wetland; significant influencing factor was ORP. Compared with the reed wetland, the PDR in reed degraded wetland had significantly reduced, whose limiting factor was TOC concentration in soil; the ration of N2O/ (N2O + N2) had increased and the pN2O had no obvious change in reed degraded wetland. © (2014) Trans Tech Publications, Switzerland. Source

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