Anaerobic degradation of decabromodiphenyl ether
Anaerobic degradation of decabromodiphenyl ether
复制标题
DOI：
10.1021/es048634j
复制
发表时间：
2005-02-15
影响因子：
11.4
通讯作者：
Kohler, M
中科院分区：
文献类型：
--
作者：
Gerecke, AC;Hartmann, PC;Kohler, M
十溴二苯醚（BDE-209）是一种广泛使用的阻燃剂，其环境安全性在过去几年中一直是有争议的讨论主题。BDE-209降解为溴化程度较低的二苯醚同系物，表现出较高的生物累积潜力，一直是一个关键问题。在此，我们报告了BDE-209在厌氧条件下的降解情况以及八溴和九溴二苯醚同系物的形成情况。从嗜温消化池收集的污水污泥被用作接种物，并在有和没有一组五个引物的情况下孵育长达238天。索氏提取和液相色谱净化程序后，通过GC/HRMS分析母体化合物和脱溴产物。在使用引物的实验中，BDE-209的浓度在238天内下降了30%。这对应于1 x 10（-3）d（-1）的伪一级降解速率常数。在没有引物的情况下，降解速率常数低50%。两种九溴二苯醚和六种八溴二苯醚同系物的形成证明，BDE-209在这些实验中发生了还原脱溴作用。脱溴发生在对位和间位，而在邻位的脱溴没有统计学意义。所有三种九溴二苯醚同系物（BDE-206、BDE-207和BDE-208）也被发现发生还原脱溴作用。在无菌对照实验中，BDE-209浓度没有显着变化，也没有观察到低溴同系物的形成。据我们所知，这是第一份证明BDE-209在厌氧条件下发生微生物介导的还原脱溴作用的报告。
The environmental safety of decabromodiphenyl ether (BDE-209), a widely used flame retardant, has been the topic of controversial discussions during the past several years. Degradation of BDE-209 into lower brominated diphenyl ether congeners, exhibiting a higher bioaccumulation potential, has been a critical issue. Here, we report on the degradation of BDE-209 and the formation of octa- and nonabromodiphenyl ether congeners under anaerobic conditions. Sewage sludge collected from a mesophilic digester was used as the inoculum and incubated up to 238 days with and without a set of five primers. Following Soxhlet extraction and a liquid chromatography cleanup procedure, parent compounds and debromination products were analyzed by GC/HRMS. In experiments with primers, concentrations of BDE-209 decreased by 30% within 238 days. This corresponds to a pseudo-first-order degradation rate constant of 1 x 10(-3) d(-1). Without primers, the degradation rate constant was 50% lower. Formation of two nonabromodiphenyl ether and six octabromodiphenyl ether congeners proved that BDE-209 underwent reductive debromination in these experiments. Debromination occurred at the para and the meta positions, whereas debromination at the ortho position was not statistically significant. All three nonabromodiphenyl ether congeners (BDE-206, BDE-207, and BDE-208) were found to undergo reductive debromination as well. No significant change of the BDE-209 concentration and no formation of lower brominated congeners was observed in sterile control experiments. To our knowledge, this is the first report demonstrating microbially mediated reductive debromination of BDE-209 under anaerobic conditions.