Defluorination of aqueous perfluorooctanesulfonate by activated persulfate oxidation

Shewei Yang; Jianhua Cheng; Jian Sun; Yongyou Hu; Xiaoyan Liang

doi:10.1371/journal.pone.0074877

Defluorination of aqueous perfluorooctanesulfonate by activated persulfate oxidation

PLoS One. 2013 Oct 7;8(10):e74877. doi: 10.1371/journal.pone.0074877. eCollection 2013.

Authors

Shewei Yang¹, Jianhua Cheng, Jian Sun, Yongyou Hu, Xiaoyan Liang

Affiliation

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.

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 > Fe(2+)/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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alkanesulfonic Acids / chemistry*
Fluorocarbons / chemistry*
Halogenation
Hydrolysis
Oxidation-Reduction
Tandem Mass Spectrometry

Substances

Alkanesulfonic Acids
Fluorocarbons
perfluorooctane sulfonic acid

Grants and funding

The authors wish to gratefully acknowledge the Project of Science and Technology Excellent Scholar of Zhu Jiang (No. 0501-64) and Fundamental research funds for the National Central Universities (No.2116520) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.