Chlorine isotope fractionation during reductive dechlorination of chlorinated ethenes by anaerobic bacteria
Chlorine isotope fractionation during reductive dechlorination of chlorinated ethenes by anaerobic bacteria
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DOI：
10.1021/es025547n
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发表时间：
2002-10-15
影响因子：
11.4
通讯作者：
Terashima, Y
中科院分区：
文献类型：
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作者：
Numata, M;Nakamura, N;Terashima, Y
研究了厌氧细菌将三氯乙烯 (TCE) 和四氯乙烯 (PCE) 还原脱氯为顺式 1,2-二氯乙烯 (cDCE) 过程中的氯同位素分馏。在一步反应（TCE 至 cDCE）过程中观察到的 (CI)-C-37/(CI)-C-35 比率的变化可以通过伴随瑞利分馏的氯的区域选择性消除来解释。 30℃时，三种厌氧培养物对TCE脱氯的分级因子(α)约为0.994-0.995。两步反应（PCE 到 cDCE）过程中有机氯中 (CI)-C-37 的富集可以通过 PCE 分子中一个氯原子的随机消除以及 TCE 分子中一个氯原子的区域选择性消除来解释。前面的分馏因子：使用数学模型估计在30℃下三种厌氧培养物的PCE脱氯的第一步为0.987-0.991。第一步期间的同位素分馏将是 PCE 脱氯至 cDCE 期间氯同位素分馏的主要因素。开发的模型可用于评估区域选择性和多步反应的分馏因子。
Chlorine isotope fractionation during reductive dechlorination of trichloroethene (TCE) and tetra chloroethene (PCE) to cis-1,2-dichloroethene (cDCE) by anaerobic bacteria was investigated. The changes in the (CI)-C-37/(CI)-C-35 ratio observed during the one-step reaction (TCE to cDCE) can be explained by the regioselective elimination of chlorine accompanied by the Rayleigh fractionation. The fractionation factors (alpha) of the TCE dechlorination by three kinds of anaerobic cultures were approximately 0.994-0.995 at 30 degreesC. The enrichment of (CI)-C-37 in the organic chlorine during the two-step reaction (PCE to cDCE) can be explained by the random elimination of one chlorine atom in the PCE molecule followed by the regioselective elimination of one chlorine atom in the TCE molecule. The fractionation factors fore: the first step of the PCE dechlorination with three kinds of anaerobic cultures were estimated to be 0.987-0.991 at 30 degreesC using a mathematical model. Isotope fractionation during the first step would be the primary factor for the chlorine isotope fractionation during the PCE dechorination to cDCE. The developed models can be utilized to evaluate the fractionation factors of regioselective and multistep reactions.