title: Kinetics and products of photo-Fenton degradation of triazophos.
abstract: Triazophos is a contaminant of wastewater at manufacturing facilities, and remediative treatment may be needed. While toxicity and persistence limit the effectiveness of biological and physicochemical methods, photo-Fenton processes are promising. UV-Fenton and solar-Fenton processes were applied to degrade triazophos. The optimum parameters were 50 mmol/L H(2)O(2), 0.3 mmol/L FeSO(4), and pH 3.0. The decomposition of triazophos by a photo-Fenton process followed first-order kinemics. At 30 degrees C, the half-life of triazophos in a UV-Fenton process ranged from 9.1 min at 2.0 x 10(5) Lx to 27.3 min at 1.0 x 10(5) Lx. At 35 degrees C and with solar irradiation luminance, it ranged within 1.0 x 10(5) -1.2 x 10(5) Lx; the half-life of triazophos in the solar-Fenton process was 11.2 min. Five major degradation products, O,O-diethyl phosphorothioic acid, monoethyl phosphorothioic acid, phosphorothioic acid, 1-phenyl-3-hydroxy-1,2,4-triazole, and phenylsemicarbazine, were tentatively identified as their corresponding trimethylsilyl derivatives with a gas chromatography-mass spectrometer. The possible degradation pathway of triazophos was proposed. The results indicate the potential use of a solar-Fenton treatment for triazophos-contaminated water.
authors.affiliation: Key Laboratory of Marine Environmental Science, Ministry of Education, Environmental Science Research Center, Xiamen University, Xiamen 361005, China.
authors.forename: Kunde
authors.initials: K
authors.lastname: Lin
authors.forename: Dongxing
authors.initials: D
authors.lastname: Yuan
authors.forename: Meng
authors.initials: M
authors.lastname: Chen
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Deng
mesh_terms: D005296:Ferrous Compounds / Q000008:administration & dosage; D006861:Hydrogen Peroxide / Q000008:administration & dosage; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D063086:Organothiophosphates / Q000737:chemistry*; D010782:Photolysis; D013472:Sunlight; D013696:Temperature; D014230:Triazoles / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D005296:Ferrous Compounds; D063086:Organothiophosphates; D014230:Triazoles; C020748:ferrous sulfate; C012584:triazophos; D006861:Hydrogen Peroxide