中文摘要：

本文模拟研究了土壤中Cd在雨水作用下的释放过程中，土壤中总Cd的释放动力学及释放过程中赋存形态的转化．结果表明，土壤中总Cd的解吸有快反应和慢反应两个过程，可用多项式、Frendlich及E10vich方程描述，且Elovich方程描述效果最优；土壤中总Cd解吸强度随土壤pH值、有机质含量的下降而增大，其中土壤pH值是主要影响因素；在低有机质、低pH值土壤中，Cd主要以可交换态存在；高有机质、高pH值土壤更有利于碳酸盐结合态、铁锰氧化态、有机结合态存在；可交换态Cd在不同pH土壤中均为最易解吸形态，土壤pH值越高，可交换态越容易向铁锰氧化态、有机结合态转化；土壤有机质越高越不利于可交换态的解吸，但有利于可交换态向其他形态转化．

英文摘要：

Batch experiments were performed to investigate the desorption kinetics and species transformation of Cd in the soil under rain. The results showed that Cd desorption could be described by Parabolic, Frendlich and Elovich equation. Elovich equation is the best fitted equation which indicates that Cd desorption could be divided into a fast reaction and a slow reaction. The release of Cd increased significantly with decreasing pH value and organic matter content of soil. Besides, the soil pH value is the main influence factor. Exchangeable Cd is the main species in low organic matter, low pH value soil. Carbonate, Mn oxide-occluded and organically bound forms are more prone to high organic matter and high pH value soil. Exchangeable Cd is the easiest to desorb in different pH soil. It is easier for the exchangeable Cd to transform into Mn oxide-occluded and organically bound Cd in High pH soils. High organic content of soil prevents desorption of exchangeable Cd, but is beneficial to its transformation into other forms.