State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China.
State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China; Department of Science and Environmental Studies, The Education University of Hong of Kong, Hong Kong Special Administrative Region, China.
J Hazard Mater. 2019 Jul 15;374:211-218. doi: 10.1016/j.jhazmat.2019.04.041. Epub 2019 Apr 13.
This study investigated the occurrence and fate of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), two chiral brominated flame retardants (BFRs) with sixteen different stereoisomers, in four Hong Kong wastewater treatment plants (WWTPs) featuring diverse treatment processes during a two-year sampling campaign. More effective HBCD removal was achieved via biodegradation as compared to sludge sorption, whereas both chemically enhanced primary treatment and secondary treatment yielded high TBECH elimination (>90%). α-HBCD (54-75%) predominated in all samples, and its proportions were increased in effluent as compared to influent and sludge. α- and β-TBECH (72.3-84.4% in total) were the predominant TBECH diastereomers, with a proportional shift from the latter to the former diastereomer mostly observed after treatment. More rapid biodegradation and preferential sorption of γ-HBCD as compared to α-HBCD as well as β-TBECH as compared to α-TBECH might account for this changing pattern. This is the first study to report the enantiomer-specific behavior of chiral BFRs in different wastewater treatment processes. A preferential elimination of (+)-α- and (+)-γ-HBCD and E-β-TBECH (the second enantiomeric elution order) took place consistently after biological treatment, possibly due to enantioselective adsorption and microbial degradation. Our results highlight the importance of conducting enantiospecific analysis for chiral pollutants in wastewater samples.
本研究调查了 1,2,5,6,9,10-六溴环十二烷（HBCD）和 1,2-二溴-4-(1,2-二溴乙基)环己烷（TBECH）这两种具有 16 个立体异构体的手性溴化阻燃剂（BFRs）在香港四个具有不同处理工艺的污水处理厂（WWTPs）中的出现和归宿。与污泥吸附相比，生物降解更有效地去除 HBCD，而化学增强的一级处理和二级处理都产生了高 TBECH 去除率（>90%）。α-HBCD（54-75%）在所有样品中占优势，其比例在出水中比在进水中和污泥中更高。α-和β-TBECH（总含量为 72.3-84.4%）是主要的 TBECH 非对映异构体，在处理后主要观察到从后者到前者非对映异构体的比例变化。与α-HBCD 相比，γ-HBCD 的生物降解速度更快，与α-TBECH 相比，β-TBECH 的吸附选择性更强，这可能解释了这种变化模式。这是首次报道手性 BFRs 在不同污水处理工艺中的对映体特异性行为的研究。在生物处理后，（+）-α-和（+）-γ-HBCD 以及 E-β-TBECH（第二个对映体洗脱顺序）的优先消除一直存在，这可能是由于对映选择性吸附和微生物降解所致。我们的研究结果强调了在废水样品中对映体特异性分析手性污染物的重要性。
