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标题：Monuron Photodegradation Products in Aqueous Solution
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作者：M. Bobu ; E. Lundanes ; I. Siminiceanu 等
期刊名称：Universitatea Politehnica din Timisoara. Buletinul Stiintific. Seria Chimie si Ingineria Mediului
印刷版ISSN：1224-6018
出版年度：2008
卷号：53(67)
期号：01-02
出版社：Universitatea Politehnica din Timisoara
摘要：The photodegradation of monuron (3-(4-chlorophenyl)-1, 1-dimethylurea) in aqueous solutions under simulated solar irradiation has been conducted in this study by different advanced oxidation processes (UV/H₂O₂, UV/H₂O₂/Fe²⁺, UV/H₂O₂/TiO₂, UV/TiO₂). The degradation rates were always higher for the homogenous catalysis in photo-Fenton reactions (UV/H₂O₂/Fe²⁺) when compared with the heterogeneous photocatalytic systems (TiO₂/UV and UV/H₂O₂/TiO₂). Optimal concentrations of Fe²⁺ and H₂O₂ for the abatement of the herbicide in the photo-Fenton system were found. Several intermediary products were identified using large volume injection micro-liquid chromatography with UV detection, LC-MS and GC-MS techniques and from the analytical data, a degradation mechanism was proposed. The degradation mechanism of monuron is initiated by the attack of hydroxyl radicals at the N-terminal group and consists of two sequential N-dealkylations followed by hydrolysis to an aniline derivate (4-chloroaniline). Further oxidations leads to ring opening and smaller organic molecules, easier to oxidize.
关键词：Monuron, μ-LC-MS, μ-LC-UV, photocatalysis, degradation products