文献类型： 外文期刊

作者： Zhu, Baotong ¹ ; Xia, Xinghui ¹ ; Wu, Shan ² ; Lu, Xiaoxia ³ ; Yin, Xin'an ¹ ;

作者机构： 1.Beijing Normal Univ, Sch Environm, State Key Lab Water Environm Simulat, Beijing 100875, Peoples R China

2.Guangdong Inst Ecoenvironm & Soil Sci, Guangdong Key Lab Agr Environm Pollut Integrated, Guangzhou 510650, Guangdong, Peoples R China

3.Peking Univ, Coll Urban & Environm Sci, Beijing 100871, Peoples R China

关键词： Polybrominated diphenyl ethers;Desorption;Microbial debromination;Black carbon;Bioavailability;Riverine sediments

期刊名称：CHEMOSPHERE （ 影响因子：7.086； 五年影响因子：6.956 ）

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收录情况： SCI

摘要： Microbial degradation plays a crucial role in eliminating polybrominated diphenyl ethers (PBDEs) in environments. However, the microbial bioavailability of PBDEs in aquatic sediments is not well understood. In this work, the bioavailability of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a typical PBDE congener, to PBDE-degrading microorganisms in natural sediments from six Chinese rivers under anaerobic conditions was investigated. The contents of black carbon (BC) and total organic carbon (TOC) in the six sediment samples were in the range of 0.025%-030% and 0.03%-3.38%, respectively. BDE-47 desorption from various sediments was fitted well with the first-order three-compartment desorption model. The desorbing fraction of sediment-associated BDE-47 at each desorption time interval exhibited a significant negative correlation with the BC content (p < 0.01). In the sediments, the anaerobic debromination of BDE-47 by microorganisms underwent a stepwise debromination pathway generating mainly three lower brominated congeners (BDE-28, -17 and 4). The microbial debromination ratio of BDE-47 ranged from 4.21% to 7.89% in various sediments after 120 d incubation anaerobically, and it negatively correlated with the content of sediment BC significantly (p < 0.01). However, the desorbing fraction and microbial debromination ratio of BDE-47 only showed weak correlations with the TOC content in sediments (p > 0.05). Furthermore, there was a significant positive correlation of desorbing fraction of BDE-47 from sediments with its microbial debromination ratio (p < 0.01) as well as with the level of its three lower brominated products (p < 0.05) after the first 20 d incubation. This study suggests that the BDE-47 bioavailability to microorganisms in anaerobic river sediments is mainly influenced by the content of sediment BC which controls the desorbing fraction of sediment-associated BDE-47. (C) 2016 Elsevier Ltd. All rights reserved.