Enhanced degradation of trichloroethene by calcium peroxide activated with Fe（III） in the presence of citric acid  

作　　者：Xiang ZHANG Xiaogang GU Shuguang LU Zhouwei MIAO Minhui XU Xiaori FU Muhammad DANISH Mark L. BRUSSEAU Zhaofu QIU Qian SUI 

机构地区：[1]State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China [2]Soil, Water and Environmental Science Department, School of Earth and Environmental Sciences, The University of Arizona, 429 Shantz Building, Tucson, AZ 85721, United States

出　　处：《Frontiers of Environmental Science & Engineering》2016年第3期502-512,共11页环境科学与工程前沿（英文）

基　　金：This study was financially supported by the National Natural Science Foundation of China （Grant Nos. 41373094 and 51208199）, China Postdoctoral Science Foundation （No. 2015M570341） and the Fundamental Research Funds for the Central Universities （No. 22A2015 14057）. The contributions of Dr. Mark Brusseau were supported by the NIEHS Superfund Research Program （P42 ES04940）.

摘　　要：Trichloroethene （TCE） degradation by Fe（III）- activated calcium peroxide （CP） in the presence of citric acid （CA） in aqueous solution was investigated. The results demonstrated that the presence of CA enhanced TCE degradation significantly by increasing the concen- tration of soluble Fe（III） and promoting H202 generation. The generation of HO· and O2^-· in both the CP/Fe（III） and CP/Fe（III）/CA systems was confirmed with chemical probes. The results of radical scavenging tests showed that TCE degradation was due predominantly to direct oxidation by HO·, while O2^-· strengthened the generation of HO· by promoting Fe（III） transformation in the CP/Fe （III）/CA system. Acidic pH conditions were favorable for TCE degradation, and the TCE degradation rate decreased with increasing pH. The presence of Cl·-, HCO3·-, and humic acid （HA） inhibited TCE degradation to different extents for the CP/Fe（III）/CA system. Analysis of Cl·- production suggested that TCE degradation in the CP/Fe （III）/CA system occurred through a dechlorination process. In summary, this study provided detailed information for the application of CA-enhanced Fe（III）-activated calcium peroxide for treating TCE contaminated groundwater.Trichloroethene （TCE） degradation by Fe（III）- activated calcium peroxide （CP） in the presence of citric acid （CA） in aqueous solution was investigated. The results demonstrated that the presence of CA enhanced TCE degradation significantly by increasing the concen- tration of soluble Fe（III） and promoting H202 generation. The generation of HO· and O2^-· in both the CP/Fe（III） and CP/Fe（III）/CA systems was confirmed with chemical probes. The results of radical scavenging tests showed that TCE degradation was due predominantly to direct oxidation by HO·, while O2^-· strengthened the generation of HO· by promoting Fe（III） transformation in the CP/Fe （III）/CA system. Acidic pH conditions were favorable for TCE degradation, and the TCE degradation rate decreased with increasing pH. The presence of Cl·-, HCO3·-, and humic acid （HA） inhibited TCE degradation to different extents for the CP/Fe（III）/CA system. Analysis of Cl·- production suggested that TCE degradation in the CP/Fe （III）/CA system occurred through a dechlorination process. In summary, this study provided detailed information for the application of CA-enhanced Fe（III）-activated calcium peroxide for treating TCE contaminated groundwater.

关 键 词：calcium peroxide trichloroethene （TCE） citric acid ferric ion free radicals OXIDATION 

分 类 号：TQ124.52[化学工程—无机化工] X703[环境科学与工程—环境工程]