Cathodic Hydrogen as Electron Donor in Enhanced Reductive Dechlorination  

作　　者：张瑞玲 路晓霞 Danny D. Reible 焦刚珍 秦松岩 

机构地区：[1]School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China [2]Anchor Qea, LLC, Austin, TX 78746, USA [3]Department of Civil & Environmental Engineering, Texas Tech University, Lubbock, TX 79409-1023, USA

出　　处：《Chinese Journal of Chemical Engineering》2013年第12期1386-1390,共5页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China（51108317）; the Municipal Natural Science Foundation of Tianjin（12JCQNJC05400）

摘　　要：In situ capping is an attractive and cost-effective method for remediation of contaminated sediments,but few studies on enhancing contaminant degradation in sediment caps have been reported,especially for chlorinated benzenes.Electrically enhanced bioactive barrier is a new process for in situ remediation for reducible compounds in soil or sediments.The primary objective of this study is to determine if electrodes in sediment could create a redox gradient and provide electron acceptor/donor to stimulate degradation of chlorinated contaminant.The results demonstrate that graphite electrodes lead to sustainable evolution of hydrogen,displaying zero-order kinetics in the initial stages with different voltages.The constant rates of hydrogen evolution at 3,4,and 5 V are1.05,2.54,and 4.3 nmol·L 1·d 1,respectively.Even higher voltage can produce more hydrogen,but it could not keep long time because the over potentials on electrode surfaces prevent its function.The study shows that 4 V is more appropriate for hydrogen evolution.The measured and evaluated concentration of 1,2,3,5-tetrachlorobenzene in pore water of sediment and concentration of sulfate show that dechlorination is inhibited at higher concentration of sulfate.In situ capping is an attractive and cost-effective method for remediation of contaminated sediments, but few studies on enhancing contaminant degradation in sediment caps have been reported, especially for chlorinated benzenes. Electrically enhanced bioactive barrier is a new process for in situ remediation for reducible compounds in soil or sediments. The primary objective of this study is to determine if electrodes in sediment could create a redox gradient and provide electron acceptor/donor to stimulate degradation of chlorinated contaminant. The results demonstrate that graphite electrodes lead to sustainable evolution of hydrogen, displaying zero-order kinetics in the initial stages with different voltages. The constant rates of hydrogen evolution at 3, 4, and 5 V are 1.05, 2.54, and 4.3 nmol·L 1·d 1, respectively. Even higher voltage can produce more hydrogen, but it could not keep long time because the over potentials on electrode surfaces prevent its function. The study shows that 4 V is more appropriate for hydrogen evolution. The measured and evaluated concentration of 1,2,3,5-tetrachlorobenzene in pore water of sediment and concentration of sulfate show that dechlorination is inhibited at higher concentration of sulfate.

关 键 词：HYDROGEN ELECTRODE REDUCTIVE DECHLORINATION capping 

分 类 号：X132[环境科学与工程—环境科学] Q946.5[生物学—植物学]