Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high res...Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight （dw）, with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs （World Health Organization-Toxic Equivalents） of the sludge were lower than 1 pg /g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra- CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.展开更多
Dewatered municipal sludge samples were collected from five municipal wastewater treatment plants （WWTPs） and one industrial WWTP in Guangzhou, China. A number of agricultural parameters and total metal concentratio...Dewatered municipal sludge samples were collected from five municipal wastewater treatment plants （WWTPs） and one industrial WWTP in Guangzhou, China. A number of agricultural parameters and total metal concentrations in the sludge were determined. Metal speciation was also studied. The results showed that sewage sludge had high organic carbon, and was rich in such nutrients as N and P. The concentrations of Mn, Zn, and Cu were the highest, followed by Ni, Pb, and Cr, Cd had the lowest concentration. In addition, the concentrations of the aforementioned heavy metals in the sludge samples were higher than those recorded in the background data for crop soils. With the exception of Cu and Cd from site S1, and Ni from sites S1, $2, and $5, all other metal concentrations conformed to permissible levels prescribed by the national application standard of acid soil in China （GB 18918--2002）. The results of the BCR sequential extraction showed that the concentrations of Mn and Zn were predominant in acid-soluble/exchangeable and reducible fractions. Cu was principally distributed in oxidizable and residual fractions, whereas Cr was present in oxidizable and residual fractions, Pb was found in the state of residual fractions, and the distribution of Ni and Cd did not show significant characteristics.展开更多
Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is nec...Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is necessary to ensure effective integration of management mechanisms and management paths.To a certain extent,it can improve the actual efficiency of digestion and treatment work and lay a foundation for the optimal operation of environmental protection management.In this paper,the treatment of excess sludge in a sewage treatment plant is studied.The method and results of anaerobic digestion test of excess sludge in a sewage treatment plant are discussed for reference only.展开更多
基金supported by the Key Project of Chinese Academy of Sciences (No. KZCX2-YW-420)the National Basic Research Program (973) of China (No.2009CB421606)the National Natural Science Foundation of China (No. 20621703)
文摘Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight （dw）, with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs （World Health Organization-Toxic Equivalents） of the sludge were lower than 1 pg /g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra- CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.
基金Project(51308132) supported by the National Natural Science Foundation of ChinaProject(2012B050300023) supported by the Scientific and Technological Planning Project of Guangdong Province,China+1 种基金Project(LYM11059) supported by the Foundation for Distinguished Young Talents in Higher Education of Guangdong,ChinaProjects(2011B090400161,2011B090400144) supported by the Cooperation Foundation for Industry,University and Research Institute,Guangdong Province and Ministry of Education of China
文摘Dewatered municipal sludge samples were collected from five municipal wastewater treatment plants （WWTPs） and one industrial WWTP in Guangzhou, China. A number of agricultural parameters and total metal concentrations in the sludge were determined. Metal speciation was also studied. The results showed that sewage sludge had high organic carbon, and was rich in such nutrients as N and P. The concentrations of Mn, Zn, and Cu were the highest, followed by Ni, Pb, and Cr, Cd had the lowest concentration. In addition, the concentrations of the aforementioned heavy metals in the sludge samples were higher than those recorded in the background data for crop soils. With the exception of Cu and Cd from site S1, and Ni from sites S1, $2, and $5, all other metal concentrations conformed to permissible levels prescribed by the national application standard of acid soil in China （GB 18918--2002）. The results of the BCR sequential extraction showed that the concentrations of Mn and Zn were predominant in acid-soluble/exchangeable and reducible fractions. Cu was principally distributed in oxidizable and residual fractions, whereas Cr was present in oxidizable and residual fractions, Pb was found in the state of residual fractions, and the distribution of Ni and Cd did not show significant characteristics.
文摘Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is necessary to ensure effective integration of management mechanisms and management paths.To a certain extent,it can improve the actual efficiency of digestion and treatment work and lay a foundation for the optimal operation of environmental protection management.In this paper,the treatment of excess sludge in a sewage treatment plant is studied.The method and results of anaerobic digestion test of excess sludge in a sewage treatment plant are discussed for reference only.
