title: Kinetics of oxidative decolorization and mineralization of Acid Orange 7 by dark and photoassisted Co2+-catalyzed peroxymonosulfate system.
abstract: A kinetic model was proposed and used to interpret the experimental data for degradation of Acid Orange 7 (AO7) in aqueous solution induced by Co(2+)/peroxymonosulfate (Co/PMS) reagent in terms of both decolorization and mineralization. The pseudo first-order decolorization rate constants are related to [Co(2+)], [PMS], reciprocal of [H(+)] and [AO7](0). Activation energy of the AO7 decolorization process was determined to be 75.7 kJ mol(-1). UV and visible light can accelerate the decolorization and mineralization process due to different mechanisms. In the combined UV/Co/PMS system, UV light can decompose PMS to generate hydroxyl ((*)OH) and sulfate radicals (SO(4)(*-)), while in the Vis/Co/PMS system, excited AO7 molecules can transfer electrons to PMS or Co(3+) and thus accelerate the decomposition of PMS and catalytic cycle of Co(3+)/Co(2+).
authors.affiliation: Department of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning Province 116024, PR China.
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Chen
authors.forename: Xianliang
authors.initials: X
authors.lastname: Qiao
authors.forename: Degao
authors.initials: D
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.forename: Jingwen
authors.initials: J
authors.lastname: Chen
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D001557:Benzenesulfonates; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D010545:Peroxides; C038288:peroxymonosulfate; D003035:Cobalt; C014722:2-naphthol orange