Synergetic Transformations of Multiple Pollutants Driven by Cr(VI)鈥揝ulfite Reactions

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• 作者：Bo Jiang ; Yukun Liu ; Jingtang Zheng ; Minghui Tan ; Zhaohui Wang ; Mingbo Wu
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：October 20, 2015
• 年：2015
• 卷：49
• 期：20
• 页码：12363-12371
• 全文大小：553K
• ISSN：1520-5851

文摘

Reduction of Cr(VI) is often deemed necessary to detoxify chromium contaminants; however, few investigations utilized this reaction for the purpose of treating other industrial wastewaters. Here a widely used Cr(VI)鈥搒ulfite reaction system was upgraded to simultaneously transform multiple pollutants, namely, the reduction of Cr(VI) and oxidation of sulfite and other organic/inorganic pollutants in an acidic solution. As(III) was selected as a probe pollutant to examine the oxidation capacity of a Cr(VI)鈥搒ulfite system. Both ^{鈥?/sup>OH and SO₄鈥⑩€?/sup> were considered as the primary oxidants for As(III) oxidation, based on the results of electron spin resonance, fluorescence spectroscopy, and specific radicals quenching. As(III)-scavenging, oxidative radicals greatly accelerated Cr(VI) reduction and simultaneously consumed less sulfite. In comparison with a Cr(VI)鈥揌₂O₂ system with 50 渭M Cr(VI), Cr(VI), the sulfite system had excellent performance for both As(III) oxidation and Cr(VI) reduction at pH 3.5. Moreover, in this escalated process, less sulfite was required to reduce Cr(VI) than the traditional Cr(VI) reduction by sulfite process. This effectively improves the environmental compatibility of this Cr(VI) detoxification process, alleviating the potential for SO₂ release and sulfate ion production in water. Generally, this study provides an excellent example of a 鈥渨aste control by waste鈥?strategy for the detoxification of multiple industrial pollutants.}