研究报告
张鸣,徐峙晖,崔春红,周立祥.生物制备β-FeOOH光催化酒石酸还原Cr(Ⅵ)的研究[J].环境科学学报,2015,35(7):2064-2069
生物制备β-FeOOH光催化酒石酸还原Cr(Ⅵ)的研究
- Study on photocatalytic reduction of Cr(Ⅵ) by tartaric acid over biosynthesized β-FeOOH
- 基金项目：国家自然科学基金(No.21277071,41371476)
- 作者
- 单位
- 张鸣
- 南京农业大学资源与环境科学学院环境工程系, 南京 210095
- 徐峙晖
- 南京农业大学理学院, 南京 210095
- 崔春红
- 南京农业大学资源与环境科学学院环境工程系, 南京 210095
- 周立祥
- 南京农业大学资源与环境科学学院环境工程系, 南京 210095
- 摘要：Cr(Ⅵ)不同于 Cr(Ⅲ),它具有明显的毒性、致癌性、致突变性,且在水体和土壤中迁移性强,因此,将Cr(Ⅵ)还原为Cr(Ⅲ)继而以Cr(OH)3沉淀形式去除,是治理Cr(Ⅵ)污染的重要措施之一.本文研究了生物制备β-FeOOH光催化酒石酸还原Cr(Ⅵ)的效率及影响因素.结果表明:在生物合成的β-FeOOH存在条件下,光催化酒石酸还原 Cr(Ⅵ) 的效率大幅提高,是没有β-FeOOH对照处理的4.35倍.β-FeOOH存在下光催化酒石酸还原 Cr(Ⅵ) 受pH、β-FeOOH浓度和酒石酸浓度的影响.在pH 2.0~5.0实验范围内, pH越低,还原率越高.当pH=5.0时,Cr(Ⅵ)还原率只有45%,pH=2.0时,Cr(Ⅵ)还原率可达到90%.β-FeOOH浓度为0.6 g·L-1时,Cr(Ⅵ)还原率达到最高.酒石酸浓度的增加有利于Cr(Ⅵ)的光催化还原.在β-FeOOH浓度为0.6 g·L-1,酒石酸浓度为200 μmol·L-1,溶液pH=2.0的最佳条件下,溶液中Cr(Ⅵ)可在80 min内100%光催化还原成 Cr(Ⅲ).本研究为生物制备β-FeOOH的应用和Cr(Ⅵ)污染治理提供了新的选择.
- Abstract：Unlike trivalent chromium, hexavalent chromium in soil and water can cause serious environmental problems due to its toxicity, mobility, carcinogenicity, and mutagenicity. Therefore, the transformation from Cr(Ⅵ) to Cr(Ⅲ) and subsequent precipitation of Cr(Ⅲ) in the form of Cr(OH)3 is one of the important strategies for controlling Cr(Ⅵ) pollution. In this paper, the photocatalytic reduction efficiency of Cr(Ⅵ) by tartaric acid in the presence or absence of biosynthesized β-FeOOH is investigated. The results showed that the photocatalytic reduction efficiency of Cr(Ⅵ) by tartaric acid in the presence of biosynthesized β-FeOOH was 4.35 times higher than that of the control without the addition of biosynthesized β-FeOOH. The photocatalytic reduction efficiency of Cr(Ⅵ) was obviously affected by many factors such as pH, catalyst amount, and tartaric acid concentrations. Within the tested pH range from 2.0 to 5.0, the lower the pH was, the higher the reduction efficiency of Cr(Ⅵ) was. For example, the Cr(Ⅵ) reduction efficiency increased from 45% at pH 5.0 to 90% at pH 2.0. The highest Cr (VI) reduction efficiency was achieved when 0.6 g·L-1 of biosynthesized β-FeOOH was added in this study. The increase of tartaric acid concentration is conducive to the photocatalytic reduction of Cr(Ⅵ). The reduction efficiency of Cr(Ⅵ) could reach 100% within 80 min under optimum testing conditions of 0.6 g·L-1 of β-FeOOH, 200 μmol·L-1 of tartaric acid, and pH 2. The outcomes of the study is helpful in the application of biosynthesized β-FeOOH and the removal of Cr(Ⅵ).
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