Concentrations and distribution of synthetic musks and siloxanes in sewage sludge of wastewater treatment plants in China.
In this study, we assessed the occurrence and distribution patterns of seven synthetic musks (SMs) and 17 siloxanes in anaerobic digested sludge samples collected at the dewatering process from 42 wastewater treatment plants (WWTPs) in China. SMs in sludge from different WWTPs exhibited similar composition profiles, and their total concentrations ranged from 47.3 ng/g to 68.2 μg/g dry weight (dw). On average, galaxolide (HHCB, 63.8%) and tonalide (AHTN, 31.7%) accounted for 95.5% of ∑SMs. The total concentrations of cyclic siloxanes ranged from <LOQ (limit of quantitation) to 36.1 μg/g dw (mean: 1.98 μg/g), while from <LOQ to 13.2 μg/g dw (mean: 0.937 μg/g) for linear siloxanes. On average, cyclic siloxanes accounted for 68% of the total siloxanes. High concentrations and detection frequencies of SMs and siloxanes in sewage sludge indicated that both of them were widely used in China. Among the sludge samples from 42 WWTPs, the concentrations of both ∑SMs and ∑siloxanes had considerable variations. We investigated the influence of potential factors (wastewater and sludge characteristics, the treatment capacity, serving population, and the treatment techniques of WWTPs) on the levels of target compounds in sludge, and found that SMs were significantly (p<0.05) correlated with the total organic carbon (TOC) of the sludge and the serving population of WWTP. There were also strong correlations (p<0.05) between the treatment capacity of WWTPs and cyclic siloxanes, as well as between the TOC of the sludge and linear siloxanes. In addition, the ecological risks of SMs and siloxanes in sewage sludge addressed to land application were assessed, which suggested that there was a low risk to the soil environment.
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
Nannan
N
Liu
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
Yali
Y
Shi
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
Wenhui
W
Li
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
Lin
L
Xu
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: caiyaqi@rcees.ac.cn.
Yaqi
Y
Cai
D002681:China; D004784:Environmental Monitoring; D005229:Fatty Acids, Monounsaturated / Q000032:analysis*; D012722:Sewage / Q000737:chemistry; D012833:Siloxanes / Q000032:analysis*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D005229:Fatty Acids, Monounsaturated; D012722:Sewage; D012833:Siloxanes; D062065:Wastewater; D014874:Water Pollutants, Chemical; C008563:musk
Bio-solids; Cyclic siloxane; Linear siloxanes; Risk quotient; Sludge; Synthetic musks