Selective Oxidation of Arsenite by Peroxymonosulfate with High Utilization Efficiency of Oxidant

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• 作者：Zhaohui Wang ; Richard T. Bush ; Leigh A. Sullivan ; Chuncheng Chen ; Jianshe Liu
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：April 1, 2014
• 年：2014
• 卷：48
• 期：7
• 页码：3978-3985
• 全文大小：376K
• 年卷期：v.48,no.7(April 1, 2014)
• ISSN：1520-5851

文摘

Oxidation of arsenite (As(III)) is a critical yet often weak link in many current technologies for remediating contaminated groundwater. We report a novel, efficient oxidation reaction for As(III) conversion to As(V) using commercial available peroxymonosulfate (PMS). As(III) is rapidly oxidized by PMS with a utilization efficiency larger than 90%. Increasing PMS concentrations and pH accelerate oxidation of As(III), independent to the availability of dissolved oxygen. The addition of PMS enables As(III) to oxidize completely to As(V) within 24 h, even in the presence of high concentrations of radical scavengers. On the basis of these observations and theoretical calculations, a two-electron transfer (i.e., oxygen atom transfer) reaction pathway is proposed. Direct oxidation of As(III) by PMS avoids the formation of nonselective reactive radicals, thus minimizing the adverse impact of coexisting organic matter and maximizing the utilization efficiency of PMS. Therefore, this simple approach is considered a cost-effective water treatment method for the oxidation of As(III) to As(V).