Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants.
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.
Guo
Li
L
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. guoli_2008@163.com
Zhang
Bing
B
Xiao
Ke
K
Zhang
Qinghua
Q
Zheng
Minghui
M
D008401:Gas Chromatography-Mass Spectrometry; D007220:Industrial Waste; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D011786:Quality Control; D012015:Reference Standards; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D007220:Industrial Waste; D012722:Sewage; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls