中文摘要：

为进一步了解土壤环境中有机物有效快速还原Cr（Ⅵ）的作用机理,通过批式试验研究了不同温度和pH条件下土壤中普遍存在的Al^3＋对酒石酸还原Cr（Ⅵ）反应速率的影响.结果表明,Al^3＋对酒石酸还原Cr（Ⅵ）有催化作用,且pH越低,Al^3＋的催化作用越明显;然而,当pH达4.5时,其催化作用几乎完全消失.前期试验结果指出,Al^3＋对只含有1个α-OH有机酸（如柠檬酸和乳酸）和只具有2个羧基的有机酸（如草酸和琥珀酸）还原Cr（Ⅵ）没有任何影响.因此,可得出Al^3＋的催化效应跟酒石酸分子中的2个α-OH与Al^3＋发生作用有关.在Al^3＋作用下,过量酒石酸对Cr（Ⅵ）还原反应符合零级反应动力学规律.

英文摘要：

The influence of Al^3＋ on the reduction of Cr（ Ⅵ ） by tartaric acid was studied in batch experimental systems at different pHs and temperatures to understand the mechanism of the rapid reduction of Cr（ Ⅵ ） by organic matter in soils. The results showed that A^3＋ greatly accelerated the reduction of Cr（ Ⅵ ） by tartaric acid. The catalysis by A^3＋ did not occur at pH 4.5 or above, but increased as the pH decreased. Our previous work had shown that A^3＋ had no effect on the reduction of Cr（ Ⅵ ） by organic acids with one a-OH （ such as citric acid and lactic acid） or with two - COOH groups （ such as oxalic acid and sueeinie acid ）. Based on these results, the catalysis of A^3＋ must be related to a reaction between A^3＋ and the two a-OH of tartaric acid. The reduction of Cr（ Ⅵ ） by tartaric acid followed zero order kinetics with excess tartaric acid in the presence of A^3＋.