Influences of pH and current on electrolytic dechlorination of trichloroethylene at a granular-graphite packed electrode
Influences of pH and current on electrolytic dechlorination of trichloroethylene at a granular-graphite packed electrode
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DOI：
10.1016/j.chemosphere.2005.11.005
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发表时间：
2006-06-01
期刊：
影响因子：
8.8
通讯作者：
Fang, Yuanxiang
中科院分区：
文献类型：
--
作者：
Al-Abed, Souhail R.;Fang, Yuanxiang
颗粒石墨填充阴极电解脱氯是一种修复氯化有机化合物的替代方法。它在各种条件下的有效性还需要实验研究。以铂网为阳极，石墨颗粒为阴极，在不同条件下对三氯乙烯(TCE)进行了脱氯实验。外加电流越大，TCE被消除的越多，生成的氢气和氧气越多。在每次脱氯实验中，电流效率随着TCE浓度的降低而降低。但是，电流效率集中系数(CECC)，即电流效率除以浓度，是更好的电流效率指标。电流对CECC的影响不显著，但对CECC影响较大。随pH值的变化而变化。PH效应是电解液参与质子还原和阴极电子转移的结果。较低的pH值有利于氯化钾中TCE的脱氯，氯化钾是一种不参与与质子和电子的阴极反应的电解液。在涉及质子还原和/或电子转移的醋酸铵和硝酸钾中，pH值通过质子限制和电子竞争影响TCE的脱氯。(C)2005爱思唯尔有限公司。保留所有权利。
Electrolytic dechlorination using a granular-graphite packed cathode is an alternative method for the remediation of chlorinated organic compounds. Its effectiveness under various conditions needs experimental investigation. Dechlorination of trichloroethylene (TCE) was conducted under various conditions in an electrolytic reactor with a platinum-gauze anode and a granular-graphite packed cathode. The higher the applied current, the more TCE was eliminated and more hydrogen and oxygen gasses were generated. Current efficiency decreased with a decrease in TCE concentration during each dechlorination experiment. But, the current efficiency concentration coefficient (CECC), which was defined as current efficiency divided by concentration, was a better indicator of current efficiency. The CECC was not significantly affected by current, but. it varied with pH value. The pH effects were results of the involvement of electrolytes in the proton reduction and the electron transfer at the cathode. A lower pH value favored TCE dechlorination in potassium chloride, which is an electrolyte that was not involved in cathode reactions with protons and electrons. In ammonium acetate and potassium nitrate, which involve proton reduction and/or electron transfer, the pH value affected TCE dechlorination through proton limitation and electron competition. (c) 2005 Elsevier Ltd. All rights reserved.