湖泊沉积柱中的高溴联苯醚及其在环境中的降解

Highly Brominated Polybrominated Diphenyl Ethers in Lake Sediment Cores and Their Potential Environmental Degradation

采用GC/MS方法分析了5个内陆湖泊(巢湖、滇池、红枫湖、青海湖和四海龙湾)钻孔沉积物中HB-PBDEs(高溴联苯醚,包括九溴和十溴的联苯醚)的垂直分布状况,并对它们的组成特征及其在环境中的降解进行了分析.结果显示,5个内陆湖泊表层沉积物中有机碳归一化后的w(ΣHB-PBDEs)为17.5～977.9 ng/g,其中滇池、红枫湖和巢湖HB-PBDEs的污染相对较为严重;与国内外其他研究相比,我国内陆湖泊沉积物中BDE-209的污染状况相对较轻.沉积物中HB-PBDEs的组成特征显示,BDE-209不但在大气传输过程中发生了明显降解,而且在进入湖泊沉积物后也发生了明显降解.由于BDE-209在不同环境介质中都可发生降解,并且降解产物为毒性更大的低溴代单体,因此进一步研究BDE-209在环境中的降解具有重要意义.

The vertical distribution of highly brominated polybrominated diphenyl ethers（HB-PBDEs,including nona-and deca-BDEs） in drilling sediments from five inland lakes（Lake Chaohu,Lake Dianchi,Lake Hongfeng,Lake Qinghai and a maar Lake Sihailongwan） were examined using GCMS method.The composition and potential environmental degradation of these compounds were also identified.The results indicated that TOC normalized total HB-PBDEs contents in the five surface sediments ranged from 17.5 to 977.9 ngg,with relatively high levels obtained from Dianchi,Hongfeng and Chaohu,which were still far less than reported data from other areas in China and developed countries.The composition of HB-PBDEs in these sediment cores suggested that considerable degradation of BDE-209 occurred not only during long-range atmospheric transport,but also in the lake sediments.Because BDE-209 can degrade to more toxic low brominated congeners in the environment,it is of great importance to further investigate the environmental degradation of BDE-209.