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Effects of carbonaceous materials on microbial bioavailability of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in sediments

Zhu, Baotong, Wu, Shan, Xia, Xinghui, Lu, Xiaoxia, Zhang, Xiaotian, Xia, Na, Liu, Ting
Journal of hazardous materials 2016 v.312 pp. 216-223
bioavailability, desorption, linear models, microorganisms, polybrominated diphenyl ethers, risk, sediments
In this study, we investigated the influence of various types of carbonaceous materials (CMs) on the bioavailability of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) to polybrominated diphenyl ether (PBDE)-degrading microorganisms in CM-amended sediments. The microbial debromination ratio of BDE-47 was reduced by 92.8%–98.2% in the 5.0% CM-amended sediment compared with in sediment without CM amendment after 100 d of anaerobic incubation. The concentrations of lower brominated products also decreased when the content of CMs increased from 0.2% to 5.0%. The inhibitory effects of CMs on BDE-47 debromination were CM content- and characteristic-specific. The reciprocals of BDE-47 debromination ratios and lower brominated product concentrations showed positive linear correlations with CM contents in sediments (p<0.01), and the slopes of linear regression fitting generally correlated with specific surface areas (SSAs) of CMs. Desorption of BDE-47 from CMs indicated the declined desorbing fraction of BDE-47 was responsible for the reduction in BDE-47 bioavailability to microorganisms, thus decreasing its debromination in sediments amended with CMs. This study revealed that CM amendment could reduce the PBDE bioavailability to PBDE-degrading microorganisms in sediments, and it is expected to help deepen our understanding of the environmental behaviors and risks of PBDEs.