污染控制技术及原理
王云燕,柴立元.“Achromobacter sp. CH-1-Cr(Ⅵ)-H2O”体系Cr(Ⅵ)还原的电化学行为[J].环境科学学报,2009,29(5):939-943
“Achromobacter sp. CH-1-Cr(Ⅵ)-H2O”体系Cr(Ⅵ)还原的电化学行为
- Electrochemical behavior of Cr(Ⅵ) reduction in Achromobacter CH-1-Cr(Ⅵ)-H2O system
- 基金项目：国家自然科学基金重点项目(No.50830301);教育部新世纪优秀人才支持计划(No.NCET-05-0689);湖南省科技计划重点项目(No.2008SK2007);长沙市科技计划项目(No.K0802144-31)
- 作者
- 单位
- 王云燕
- 中南大学冶金科学与工程学院, 长沙 410083
- 柴立元
- 中南大学冶金科学与工程学院, 长沙 410083
- 摘要：采用循环伏安法探明了"Achromobacter sp.CH-1-Cr(Ⅵ)-水"体系的电化学行为.结果表明:循环伏安曲线上-0.62V(相对于SCE)的电流峰对应的反应为Cr(VI)还原成Cr(Ⅲ)的反应,在电势为-0.82V时Cr(Ⅲ)开始还原为零价铬.体系中的电极反应为不可逆过程,阳极扫描时Cr(Ⅲ)不会被重新氧化为Cr(Ⅵ).细菌的存在使Cr(Ⅵ)的还原更容易进行,其还原峰电势正移约0.2V,细菌对体系中的电化学反应起了催化作用.随细菌量的增加,氢气的析出、六价铬还原为三价铬及三价铬进一步还原为零价铬的电势均发生了正移,过高的细菌量主要影响三价铬还原沉积为金属铬的过程.铬浓度对细菌还原Cr(Ⅵ)溶液的循环伏安曲线的影响不大.初始pH值为10是细菌还原Cr(Ⅵ)的最佳pH值.
- Abstract：The electrochemical behavior of an 'Achromobacter sp.CH-1-Cr(Ⅵ)-H2O' system was investigated by cyclic voltammetry.Results indicated that the peak current at-0.62 Vvs.SCEin the cyclic voltammetric curve represented the reduction reaction of Cr(VI)to Cr(Ⅲ),and the reduction of Cr(Ⅲ)to Cr occurred at-0.82 V.The electrode reaction of the system was irreversible,so Cr(Ⅲ)could not be oxidized to Cr(VI)under positive scanning.The presence of the bacterium Achromobacter sp.CH-1 as catalyst promoted the reduction of Cr(VI)by shifting the potential of the reduction peak by 0.2 V.The reduction potentials of hydrogen evolution,reduction of Cr(Ⅵ)to Cr(Ⅲ),and reduction of Cr(Ⅲ)to Cr all shifted positively with the addition of Achromobacter sp.CH-1.High bacterial biomass mainly affected the reduction process and precipitation of Cr(Ⅲ).However,the Cr(Ⅵ)concentration had a minor influence on the electrochemical behavior of the 'Achromobacter sp.CH-1-Cr(Ⅵ)-H2O' system.An initial pHvalue of 10 was optimal for Cr(Ⅵ)reduction.
摘要点击次数： 2302 全文下载次数： 2467
