Behavior of As(V) with ZVI鈥揌2O System and the Reduction to As(0)

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• 作者：Priyanka Mondal ; Subhamoy Bhowmick ; Nora Jullok ; Wenyuan Ye ; Wouter Van Renterghem ; Sven Van den Berghe ; Bart Van der Bruggen
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：September 18, 2014
• 年：2014
• 卷：118
• 期：37
• 页码：21614-21621
• 全文大小：474K
• ISSN：1932-7455

文摘

The interaction of As(V) with zerovalent iron (ZVI) and H₂O system was studied under oxic and anoxic conditions. XRD and XPS analysis of the ZVI confirmed the core鈥搒hell Fe⁰ structure with an outer coating of iron oxide/hydroxide. Batch experiments showed that the rate of removal of As(V) was very fast for oxic compared to anoxic condition. Under open atmospheric environment, the analysis revealed that ZVI spontaneously reacts with water and oxygen to form a number of iron oxide/hydroxides and the As(V) is removed from the solution by sorption/coprecipitation onto these corrosion products. However, reduction of As(V) did not take place in such experimental conditions. On the other hand, in anoxic conditions, reduction of As(V) to As(III) and As(0) was demonstrated via XPS analysis. Electrons, Fe²⁺_(s), and H_(s) formed from Fe⁰ oxidation were thought to be the reducing agents for such reduction process. Therefore, the inherent oxide/hydroxide layer on the ZVI surface plays an important role and helps in the indirect reduction of As(V). Thus, the present study delineates the possible mechanism of As(V) reduction with ZVI-H₂O system where the formation of As(0) is important in view of arsenic immobilization.