中文摘要：

通过批式试验研究了高岭百表面吸附态Mn（Ⅱ）对草酸、柠檬酸和酒石酸还原Cr（Ⅵ）的影响。结果表明，高岭石表面吸附态Mn（Ⅱ）对3种有机酸还原Cr（Ⅵ）均有良好的催化作用，其效果大小依次为：草酸、柠檬酸、酒石酸。酒石酸为还原剂，当其初始浓度≤2．0mmol·L^-1时，高岭石表面吸附态Mn（Ⅱ）对酒石酸还原Cr（Ⅵ）的催化作用不显著，但其催化作用随酒石酸初始浓度的增加而明显提高。温度和pH对高岭石表面吸附态Mn（Ⅱ）催化草酸和柠檬酸还原Cr（Ⅵ）有显著影响，温度越高，反应速率越快；当pH在3．5～4．5范围内，草酸对Cr（Ⅵ）的还原反应速率随pH的降低而显著升高；然而，柠檬酸对Cr（Ⅵ）的还原速率却在pH=4．0时为最快。

英文摘要：

The influence of Mn （ Ⅱ ） adsorbed by kaolinite on the reduction of Cr （Ⅵ） by oxalic, citric and tartaric acids is investigated through batch experiments. The resuhs show that Mn （ Ⅱ ） adsorbed by kaolinite accelerates the reduction of Cr （Ⅵ） by the three organic acids, and the catalysis is in the order： oxalic acid, citric acid, tartaric acid. When the concentration of tartaric acid is lower than 2. 0 mmol·L^-1, the catalysis of adsorbed Mn （ Ⅱ ） is not obviously observed, but it becomes manifest with a higher concentration. The temperature and pH exert great impact on the reduction of Cr （Ⅵ） by oxalic and citric acid, and the reaction rates increase with temperature. When pH ranges from 3.5 - 4. 5, the reduction of Cr （Ⅵ） by oxalic acid increases with pH decreasing. However, the reduction of Cr （Ⅵ） by citric acid is the fastest at pH =4. 0.