The synergistic interaction between sulfate-reducing bacteria and pyrogenic carbonaceous matter in DDT decay
The synergistic interaction between sulfate-reducing bacteria and pyrogenic carbonaceous matter in DDT decay
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DOI：
10.1016/j.chemosphere.2019.05.208
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发表时间：
2019-10-01
期刊：
影响因子：
8.8
通讯作者：
Xu, Wenqing
中科院分区：
文献类型：
--
作者：
Ding, Kai;Duran, Metin;Xu, Wenqing
虽然1，1，1-三氯-2，2-二(4-氯苯基)乙烷(DDT)于1972年在美国被禁用，但在热源碳质(PCM)和硫酸盐还原细菌(SRB)共存的沉积物中仍经常检测到DDT。在本研究中，我们发现在SRB和石墨粉(一种典型的PCM)存在下，21天后，70.2+/-0.2%的DDT消失。我们的结果表明，观察到的DDT衰变是由于石墨粉和SRB产生的还原硫物种之间的反应所致。石墨粉表面未见生物膜形成。相反，石墨粉的存在抑制了SRB的活性。为了了解PCM在DDT衰变中的作用，采用了电化学池和间歇式反应器对硫磺处理的PCM进行了实验，并用恒电位器直接电化学还原。我们的结果表明，多硫化物、硫化物、亚硫酸盐和硫代硫酸盐都可以与PCM反应，形成表面结合的中间体，从而导致DDT衰变。还原硫物种对多硫化物的反应活性最高，其次是硫化物、亚硫酸盐和硫代硫酸盐。(C)2019爱思唯尔有限公司。保留所有权利。
Although 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane (DDT) was banned in the United States in 1972, it is still often detected in sediments where pyrogenic carbonaceous matter (PCM) and sulfate-reducing bacteria (SRB) co-exist. In this study, we found that 70.2 +/- 0.2% of DDT disappeared in the presence of SRB and graphite powder, a model PCM, after 21 days at pH 7. Our results suggest that the observed DDT decay was due to the reaction between graphite powder and the reduced sulfur species that were produced by SRB. No biofilm formation was observed on the surface of graphite powder. Rather, the activity of SRB was inhibited by the presence of graphite powder. To understand the involvement of PCM in DDT decay, electrochemical cells and batch reactor experiments with sulfur-pretreated PCM as well as direct electrochemical reduction by a potentiostat were employed. Our results suggest that polysulfide, sulfide, sulfite, and thiosulfate could all react with PCM, forming surface-bound intermediates that subsequently led to DDT decay. The reactivity of reduced sulfur species was the highest for polysulfide, followed by sulfide, sulfite, and thiosulfate. (C) 2019 Elsevier Ltd. All rights reserved.