Degradation of atrazine in aqueous medium by electrocatalytically generated hydroxyl radicals. A kinetic and mechanistic study

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• 作者：Beytul Balci ; Nihal Oturan ; Richard Cherrier ; Mehmet A. Oturan
• 关键词：Atrazine ; Electro-Fenton ; BDD anode ; Hydroxyl radicals ; Cyanuric acid ; Mineralization
• 刊名：Water Research
• 出版年：2009
• 出版时间：April 2009
• 年：2009
• 卷：43
• 期：7
• 页码：1924-1934
• 全文大小：648 K

文摘

Oxidative degradation of atrazine by hydroxyl radicals (OH) was studied in aqueous medium. OH were formed in situ from electrochemically generating Fenton's reagent by an indirect electrochemical advanced oxidation process. Identification and evolution of seven main aromatic metabolites and four short-chain carboxylic acids were performed by using liquid chromatography analyses. Total organic carbon (TOC) and ionic chromatography were used in order to evaluate the mineralization efficiency of treated aqueous solutions. A high mineralization rate of 82 % (never reported until now) was obtained. The oxidative degradation of cyanuric acid, the ultimate product of atrazine degradation, was highlighted for the first time. The absolute rate constant of the reaction between atrazine and hydroxyl radicals was evaluated by competition kinetics method as (2.54 ± 0.22) × 10⁹ M⁻¹ s⁻¹. Considering all oxidation reaction intermediates and end products a general reaction sequence for atrazine degradation by hydroxyl radicals was proposed.