Novel Contaminant Transformation Pathways by Abiotic Reductants

详细信息    查看全文

• 作者：Shengwen Chen ; Dimin Fan ; Paul G. Tratnyek
• 刊名：Environmental Science & Technology Letters
• 出版年：2014
• 出版时间：October 14, 2014
• 年：2014
• 卷：1
• 期：10
• 页码：432-436
• 全文大小：279K

文摘

Environmentally relevant abiotic reductants, such as zerovalent iron (ZVI) and minerals containing divalent iron (DVI), react predominantly by electron-transfer mechanisms with a variety of contaminant and probe compounds. Other reduction mechanisms involving activated forms of hydrogen (H_ads or H^{鈥?/sup>) have been suggested, but most evidence for these is only from systems containing noble metals that catalyze hydrogen activation (e.g., Pd). Here, 2-chlorophenylethanol and relatives of this aromatic halohydrin are used as probe compounds to show that ZVI can affect reduction by several novel pathways that are not observed with DVI minerals. These pathways include dechlorination by intramolecular nucleophilic substitution and epoxide ring opening by reduction. The former appears to be catalyzed by hydroxyl groups associated with oxides on actively corroding ZVI, and the latter can arise from hydride transfer (from NaBH₄) or electron transfer (from ZVI).}