Removal of Acetaminophen Using Enzyme-Mediated Oxidative Coupling Processes: I. Reaction Rates and Pathways

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• 作者：Junhe Lu ; Qingguo Huang ; Liang Mao
• 刊名：Environmental Science & Technology
• 出版年：2009
• 出版时间：September 15, 2009
• 年：2009
• 卷：43
• 期：18
• 页码：7062-7067
• 全文大小：199K
• 年卷期：v.43,no.18(September 15, 2009)
• ISSN：1520-5851

文摘

We found that acetaminophen could be effectively transformed and removed from water by laccase-mediated oxidative coupling processes. The removal of acetaminophen followed second-order kinetics with first-order to the concentrations of both the substrate and the enzyme. Mass spectrum analysis demonstrated that polymerization through radical−radical coupling mechanism was the pathway leading to acetaminophen transformation. Coupling products thus formed are believed to be biologically inactive and more readily removable from water. Secondary mass spectra of the dimers in combination with molecular modeling analysis further elucidated that the coupling proceeded via covalent bonding between two molecules at their unsubstituted carbons in benzene rings. These findings demonstrated that laccase-mediated oxidative coupling can potentially serve as an alternative strategy to control certain micropollutants in water/wastewater treatment and reuse.