Exploring the bioaccessibility of polybrominated diphenyl ethers (PBDEs) in sewage sludge.
Environmental risks of polybrominated diphenyl ethers (PBDEs) in sewage sludge are assessed based on the concentration by exhaustive extraction, which is a likely overestimation of the pool available to exposed organisms. This study evaluated the bioaccessibility of PBDEs in sewage sludge from Shanghai using a 3-compartment model and a 6-d Tenax extraction. The very slowly fraction contributed 56-88% of total PBDEs in spiked sludge, whereas the rapidly desorbing fraction contributed only 1.1-10%. For the same PBDE congener, the rapidly desorbing fractions for sewage sludge measured in the present study were lower than those for sediment. The bioaccessible concentrations of PBDEs were 2.3-56 ng/g dry weight in sewage sludge from Shanghai, which represented 5.2% of the concentration determined by exhaustive (Soxhlet) extraction. BDE-209 was the predominant congener in sludge, contributing to 63% of the total. Moreover, the Ratio between 6-h Tenax and Soxhlet concentrations (T/S Ratio, indicating bioaccessibility) was lower in sludge generated from industrial wastewater treatment compared to sludge from facilities that treated mostly domestic wastewater. The T/S Ratio of PBDE congeners was related to KOW, specifically as KOW increases, the T/S Ratio decreased. These results will improve understanding of the fate and potential toxicity of PBDEs during land and/or landfill application of sewage sludge.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. Electronic address: xzmeng@tongji.edu.cn.
Xiang-Zhou
XZ
Meng
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Nan
N
Xiang
Department of Biotechnology, Guangzhou Medical University, Guangzhou 510182, China.
Lihong
L
Yu
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Jiying
J
Zhang
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Ling
L
Chen
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Xiaohu
X
Dai
D001682:Biological Availability; D002681:China; D055768:Halogenated Diphenyl Ethers / Q000032:analysis*; D007220:Industrial Waste / Q000032:analysis; D008962:Models, Theoretical; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D055768:Halogenated Diphenyl Ethers; D007220:Industrial Waste; D062065:Wastewater; D014874:Water Pollutants, Chemical
Bioaccessibility; Polybrominated diphenyl ethers; Sewage sludge; Tenax extraction