溶解氧对零价铁去除水中六价铬的影响  

Effects of Dissolved Oxygen on Removal of Cr(Ⅵ) by Zero-valent Iron

作　　者：曹茜[1] 陈家玮[1] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083

出　　处：《现代地质》2013年第2期435-439,共5页Geoscience

基　　金：中国地质调查局项目(1212011120288);中央高校基本科研业务费专项(2012123;2010ZD14);国家"水体污染控制与治理"科技重大专项(2009ZX07424-002)

摘　　要：六价铬Cr(Ⅵ)有巨毒性,对人类及生态环境有极大危害,运用纳米零价铁(nZVI)去除水中六价铬是一种快速高效的环境修复手段。前人的研究更多报道了pH值、温度、初始浓度等因素的影响,溶解氧(DO)的存在对于nZVI去除水体中Cr(Ⅵ)的作用却少有研究。在对比普通铁粉和纳米铁对六价铬去除的基础上,着重探讨了溶解氧(DO)对水中六价铬去除效果的影响及作用机制。批实验短期结果表明:由于纳米铁有较大的比表面积和更高的反应活性,导致nZVI的除Cr(Ⅵ)效率明显高于普通铁粉;溶解氧的存在促进了nZVI对Cr(Ⅵ)的去除,这是因为氧化作用产生较多的Fe2+,有利于Cr(Ⅵ)的去除,随着nZVI进一步氧化,产生的针铁矿、磁铁矿等铁氧化物能够进一步吸附Cr(Ⅵ),使得在有氧环境下Cr(Ⅵ)的去除效果好于无氧环境。Nanoscale zero-valent iron （nZⅥ） is a kind of effective material for remediation of polluted soil and water. It can be used to remove hexavalent chromium, Cr （ Ⅵ）, which is toxic and easily mobile in the envi- ronment. In recent years, many researches have studied impacts of temperature, pH value, initial concentra- tion, etc. in the systems, while dissolved oxygen （DO） is seldom to discuss. Herein, we compared zero-valent iron （ZⅥ） and nZⅥ for Cr （ Ⅵ ） removal in the presence or absence of oxygen in water. We focused on the effect of DO on removal of Cr（ Ⅵ ） by nZⅥ. The short-term batch experiment showed that nZⅥ is significantly more effective in removing Cr （ Ⅵ ） than ZⅥ due to large specific surface area and high activity of nano parti- cles. Oxygen enhances Cr（ V[ ） removal in water by nZⅥ in that more production of Fe2 ＋ , goethite, magnetite, etc. can be useful in this process and iron oxides can easily adsorb Cr（ Ⅵ ） on the surface of nZⅥ in the pres- ence of oxygen.

关 键 词：纳米零价铁 溶解氧 六价铬 吸附 

分 类 号：P595[天文地球—地球化学] X142[天文地球—地质学]