文献类型：期刊文献

英文题名：Oxidation of 1,1,1-Trichloroethane Stimulated by Thermally Activated Persulfate

作者：Gu, Xiaogang[1];Lu, Shuguang[1];Li, Lin[1];Qiu, Zhaofu[1];Sui, Qian[1];Lin, Kuangfei[1];Luo, Qishi[2]

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China;[2]Shanghai Acad Environm Sci, Shanghai 200233, Peoples R China

年份：2011

卷号：50

期号：19

起止页码：11029

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20121814976927);WOS:【SCI-EXPANDED(收录号:WOS:000295237000017)】；

基金：This study was financially supported by a grant (201109013) from the National Environmental Protection Public Welfare Science and Technology Research Program of China, the National Natural Science Foundation of China (Grant 40871223), and a Shanghai Postdoctoral Grant (11R21412500).

语种：英文

外文关键词：Biological materials - Groundwater pollution - Remediation - Dichloromethane - Chemical analysis - Oxidation - Rate constants - Degradation

摘要：In this study, thermally activated persulfate (PS) to stimulate the oxidation of 1,1,1-trichloroethane (TCA) in groundwater remediation was investigated. The effects of various factors including temperature; initial TCA concentration; PS/TCA molar ratio; solution pH; and common constituents in groundwater such as Cl-, HCO3-, SO42-, and NO3- anions and humic acid (HA) were evaluated. The experimental results showed that TCA can be completely oxidized in 2 h at 50 degrees C with a PS/TCA molar ratio of 100/1, indicating the effectiveness of thermally activated PS oxidation for TCA removal. TCA oxidation was fitted with a pseudo-first-order kinetic model, and the rate constant was found to increase with increasing temperature and PS/TCA molar ratio, but to decrease with increasing initial TCA concentration. In addition, acidic conditions were favorable to TCA removal and elevating, the initial solution pH value (from pH 3 to 11) decreased the TCA degradation rate. Anions Cl- and HCO3- had negative effects on TCA removal, whereas the effects of both SO42- and NO3- were negligible. With 5-10 mg L-1 of HA in solution, an inhibitive effect was observed, indicating that dissolved organic matter consumed some of the oxidant. However, the anticipated effective thermally activated PS oxidation of TCA in groundwater from a real contaminated site was not achieved because of the complex solution matrix. On the other hand, the TCA degradation mechanism derived from GC/MS analytical results confirmed formic acid, dichloromethane, and trichloromethane as the primary intermediates, and therefore, two TCA decomposition pathways were proposed. In conclusion, thermally activated PS oxidation is a highly promising technique for TCA-contaminated groundwater remediation, but more complex constituents in in situ groundwater should be carefully considered for its practical application.