中文摘要：

采用原状土柱进行模拟淋溶试验，比较研究了3种低分子有机酸条件对土壤中重金属Pb、Cd、Cu和Zn的影响，以及HPO^2-4对低分子有机酸淋溶土壤中重金属的影响。结果表明，3种低分子有机酸淋溶液对供试土壤中Pb、Cd、Cu和Zn都具有解吸作用。相同低分子有机酸浓度淋溶条件下，在对Pb和Cd的淋溶中，各低分子有机酸能力大小顺序为柠檬酸〉酒石酸〉草酸；Cu的解吸顺序为柠檬酸〉草酸〉酒石酸；Zn的解吸顺序为酒石酸〉柠檬酸〉草酸。低分子有机酸浓度的增加有利于对土壤中重金属的解吸。重金属形态分析结果表明，土壤中重金属的解吸部分主要来自水溶态、可交换态和碳酸盐结合态3种形态，淋溶过程与重金属的形态分布情况有关。HPO^2-4的加入对解吸过程产生抑制作用。

英文摘要：

The effects of three low molecular weight organic acids （LMWOAs）and the medium condition （-HPO^2-4） on Pb, Cd, Cu and Zn leaching in contaminated soil were investigated by simulated leaching experiment. The results showed that Pb, Cd, Cu and Zn in the contaminated soil can be partly dissolved by different LMWOAs solutions in batch experiment. The leaching trends of Pb, Cd, Cu and Zn by LMWOAs in soils were：citric acid〉tratric acid〉oxalic acid for Pb and Cd, citric acid〉oxalic acid〉tratric acid for Cu, tratric acid〉citric acid〉oxalic acid for Zn. The desorption rate of Pb, Cd, Cu and Zn increased with the increase of concentration of LMWOAs, and the desorption was restrained by the addition of HPO^2-4. Results of sequential extraction procedure showed that heavy metals dissolved by LMWOAs mainly came from water soluble, exchangeable and carbonate fractions.