학술논문
Are free radicals actually responsible for enhanced oxidation of contaminants by Cr(VI) in the presence of bisulfite?
Document Type
Academic Journal
Author
Gao Y; Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.; Pan HP; Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.; Zhou Y; Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.; Wang Z; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.; Pang SY; Key Laboratory of Songliao Aquatic Environment, Ministry of Education, School of Municipal and Environmental Engineering, Jilin Jianzhu University, Changchun, 130118, China.; Guan CT; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.; Shen YM; Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, 116023, China.; Jiang J; Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China. Electronic address: jiangjinhit@126.com.
Source
Publisher: Elsevier Science Ltd Country of Publication: England NLM ID: 0320657 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-1298 (Electronic) Linking ISSN: 00456535 NLM ISO Abbreviation: Chemosphere Subsets: MEDLINE
Subject
Language
English
Abstract
Recently, the technology for the remediation of Cr(VI) pollutant via bisulfite has been found to be effective for fast elimination of co-contaminants especially in acidic solution, where free radicals (i.e., sulfate and/or hydroxyl radicals) are proposed to act as dominant oxidants. Here, it was demonstrated that high-valent Cr intermediate played a primary role in the Cr(VI)/bisulfite system through applying methyl phenyl sulfoxide (PMSO) as a probe. PMSO was effectively transformed in the Cr(VI)/bisulfite system with appreciable generation of methyl phenyl sulfone (PMSO 2 ) product, while PMSO was oxidized by free radicals to hydroxylated and/or polymeric products rather than PMSO 2 . The involvement of high-valent Cr species was further supported by the formation of 18 O-labeled PMSO 2 in 18 O labeling experiments, where the incorporation of 18 O from solvent water H 2 18 O into PMSO 2 was likely resulted from competitive oxygen exchange of Cr-oxo species with water. The relative contribution of high valent Cr species versus free radicals was evaluated based on the yield of PMSO 2 , which was dependent on the solution chemistry such as [Cr(VI)]:[bisulfite] ratio and dissolved oxygen. This work advances the understanding of chromium chemistry involved in the Cr(VI)/bisulfite system. These findings have important implications on the application of this "waste control by waste" technology for environmental decontamination.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)
(Copyright © 2020 Elsevier Ltd. All rights reserved.)