通过干旱区绿洲土壤Cd/Zn 和Cd/Zn/Pb 复合作用下的盆栽试验,对比研究了外源Pb 的添加对Cd/Zn复合污染土壤中Cd, Zn的形态分布与再分配的影响。结果表明：两种组合下Cd, Zn的主要赋存形态都为碳酸盐结合态和铁锰氧化态,说明Pb的添加对Cd/Zn复合污染土壤中Cd, Zn的主要赋存形态无明显影响。 Cd的全量是影响其可交换态、碳酸盐结合态和铁锰氧化态含量的主要因素, Zn的5种形态含量的主要影响因素都为Zn的全量。随着外源添加量的增加, Cd, Zn在土壤中的总再分配系数增大,结合强度系数减小,表明Cd, Zn的总量越大,各形态间的稳定性越低,潜在危害越大。两种组合比较可知, Pb的添加使Cd/Zn复合污染土壤中Cd的活性增强, Zn的活性减弱。%A pot experiment was conducted to study the effect of Pb on the redistribution and the distribution of different forms of Cd and Zn in soil polluted by Cd and Zn, by testing 2 different combinations of heavy metals Cd/Zn and Cd/Zn/Pb. The results showed that the main forms of Cd and Zn were carbonate bounded form and Fe-Mn oxide form in 2 different combinations; so there was not significant effect of Pb on the main forms of Cd and Zn in Cd/Zn combined polluted soil. The total capacity of Cd was the main influence factor on its exchangeable form, carbonate bounded form and Fe-Mn oxide form. But the total capacity of Zn was the main influence factor on all of its forms. With the concentrations of Cd and Zn being increased, the redistribution index of Cd and Zn increased, and their combination indexes decreased. With the total capacity of Cd and Zn being increased, the stability of different forms became weaker, and the potential hazards of heavy metals became greater. Pb could increase the availability of Cd, but decrease the availability of Zn in compound contaminated soil.
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