Defluorination of Aqueous Perfluorooctanesulfonate by Activated Persulfate Oxidation |
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| Authors: | Shewei Yang Jianhua Cheng Jian Sun Yongyou Hu Xiaoyan Liang |
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| Institution: | 1. Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou, Guangdong, China.; 2. State Key Lab of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou, Guangdong, China.; Queen''s University Belfast, United Kingdom, |
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| Abstract: | Activated persulfate oxidation technologies based on sulfate radicals were first evaluated for defluorination of aqueous perfluorooctanesulfonate (PFOS). The influences of catalytic method, time, pH and K2S2O8 amounts on PFOS defluorination were investigated. The intermediate products during PFOS defluorination were detected by using LC/MS/MS. The results showed that the S2O8
2− had weak effect on the defluorination of PFOS, while the PFOS was oxidatively defluorinated by sulfate radicals in water. The defluorination efficiency of PFOS under various treatment was followed the order: HT (hydrothermal)/K2S2O8 > UV (ultraviolet)/K2S2O8 > Fe2+/K2S2O8 > US (ultrasound)/K2S2O8. Low pH was favorable for the PFOS defluorination with sulfate radicals. Increase in the amount of S2O8
2− had positive effect on PFOS defluorination. However, further increase in amounts of S2O8
2− caused insignificant improvement in PFOS defluorination due to elimination of sulfate radicals under high concentration of S2O8
2−. CF3(CF2)nCOOH (n = 0–6) were detected as intermediates during PFOS defluorination. Sulfate radicals oxidation and hydrolysis were the main mechanisms involved in defluorination process of PFOS. |
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