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现代地质 ›› 2013, Vol. 27 ›› Issue (2): 435-439.DOI: P595;X142

• 水文与环境地质学 • 上一篇    下一篇

溶解氧对零价铁去除水中六价铬的影响

曹茜, 陈家玮   

  1. 中国地质大学 地球科学与资源学院,北京100083
  • 收稿日期:2012-06-04 修回日期:2013-01-17 出版日期:2013-04-01 发布日期:2013-04-22
  • 通讯作者: 陈家玮,男,教授,博士,1974年出生,地球化学专业,从事地球化学研究和教学工作。
  • 作者简介:曹茜,女,硕士研究生,1989年出生,地球化学专业,主要从事环境地球化学研究。Email:caoxi89@126com。
  • 基金资助:

    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)。
    作者简介:

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

CAO Xi, CHEN Jia-wei   

  1. School of Earth Sciences and Resources, China University of Geosciences, Beijing100083,China
  • Received:2012-06-04 Revised:2013-01-17 Online:2013-04-01 Published:2013-04-22

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。

关键词: 纳米零价铁, 溶解氧, 六价铬, 吸附

Abstract:

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 environment. In recent years, many researches have studied impacts of temperature, pH value, initial concentration, 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 particles. Oxygen enhances Cr(Ⅵ) 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 presence of oxygen.

Key words: nanoscale zero-valent iron, dissolved oxygen, Cr(Ⅵ), adsorption