Sequential Reductive and Oxidative Biodegradation of Chloroethenes Stimulated in a Coupled Bioelectro-Process
Sequential Reductive and Oxidative Biodegradation of Chloroethenes Stimulated in a Coupled Bioelectro-Process
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DOI：
10.1021/es200801r
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发表时间：
2011-08-01
影响因子：
11.4
通讯作者：
Tiehm, Andreas
中科院分区：
文献类型：
--
作者：
Lohner, Svenja T.;Becker, Dirk;Tiehm, Andreas
本文首次展示了电化学过程的成功应用，以刺激矿物介质和受污染地下水中全氯乙烯（PCE）的连续还原/氧化微生物降解。在流通柱系统中，阴极产生的氢气支持四氯乙烯还原脱氯为顺式二氯乙烯 (cDCE)、氯乙烯 (VC) 和乙烯 (ETH)。在阳极电解产生的氧气使得较低氯化代谢物随后发生氧化降解。 cDCE 的需氧共代谢降解被证明是完全消除代谢物的瓶颈。证明 PCE 负载量约为 1.5 μmol/d 时可完全去除氯乙烯。在矿物介质中，使用不锈钢电极的长期运行已被证明超过 300 天。在受污染的地下水中，不锈钢阳极发生腐蚀，而 DSA（尺寸稳定阳极）被证明是稳定的。在阴极观察到钙质沉积物的沉淀，导致 vi 电压需求和脱氯活性降低。利用 DSA 和污染场地的地下水，两个月内地下水中的氯乙烯得到完全降解，从而证明了顺序生物电方法在现场应用的可行性。
This article for the first time demonstrates successful application of electrochemical processes to stimulate sequential reductive/oxidative microbial degradation of perchloroethene (PCE) in mineral medium and in contaminated groundwater. In a flow-through column system, hydrogen generation at the cathode supported reductive dechlorination of PCE to cis-dichloroethene (cDCE), vinyl chloride (VC), and ethene (ETH). Electrolytically generated oxygen at the anode allowed subsequent oxidative degradation of the lower chlorinated metabolites. Aerobic cometabolic degradation of cDCE proved to be the bottleneck for complete metabolite elimination. Total removal of chloroethenes was demonstrated for a PCE load of approximately 1.5 mu mol/d. In mineral medium, long-term operation with stainless steel electrodes was demonstrated for more than 300 days. In contaminated groundwater, corrosion of the stainless steel anode occurred, whereas DSA (dimensionally stable anodes) proved to be stable. Precipitation of calcareous deposits was observed at the cathode, resulting in vi voltage demand and reduced dechlorination activity. With DSA and groundwater from a contaminated site, complete degradation of chloroethenes in groundwater was obtained for two months thus demonstrating the feasibility of the sequential bioelectro-approach for field application.