title: Activation of Peroxymonosulfate by Benzoquinone: A Novel Nonradical Oxidation Process.
abstract: The reactions between peroxymonosulfate (PMS) and quinones were investigated for the first time in this work, where benzoquinone (BQ) was selected as a model quinone. It was demonstrated that BQ could efficiently activate PMS for the degradation of sulfamethoxazole (SMX; a frequently detected antibiotic in the environments), and the degradation rate increased with solution pH from 7 to 10. Interestingly, quenching studies suggested that neither hydroxyl radical (•OH) nor sulfate radical (SO4•-) was produced therein. Instead, the generation of singlet oxygen (1O2) was proved by using two chemical probes (i.e., 2,2,6,6-tetramethyl-4-piperidinol and 9,10-diphenylanthracene) with the appearance of 1O2 indicative products detected by electron paramagnetic resonance spectrometry and liquid chromatography mass spectrometry, respectively. A catalytic mechanism was proposed involving the formation of a dioxirane intermediate between PMS and BQ and the subsequent decomposition of this intermediate into 1O2. Accordingly, a kinetic model was developed, and it well described the experimental observation that the pH-dependent decomposition rate of PMS was first-order with respect to BQ. These findings have important implications for the development of novel nonradical oxidation processes based on PMS, because 1O2 as a moderately reactive electrophile may suffer less interference from background organic matters compared with nonselective •OH and SO4•-.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin, Heilongjiang 150040, China.
authors.forename: Su-Yan
authors.initials: SY
authors.lastname: Pang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin, Heilongjiang 150040, China.
authors.forename: Xue-Ting
authors.initials: XT
authors.lastname: Lu
authors.affiliation: Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin, Heilongjiang 150040, China.
authors.forename: Li-Peng
authors.initials: LP
authors.lastname: Yuan
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D002384:Catalysis; D002853:Chromatography, Liquid / Q000379:methods; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D013420:Sulfamethoxazole / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D016227:Benzoquinones; D010545:Peroxides; D013431:Sulfates; D014874:Water Pollutants, Chemical; C069025:sulfate radical; C038288:peroxymonosulfate; D017665:Hydroxyl Radical; C004532:quinone; D013420:Sulfamethoxazole