Abstract:
Soil samples were taken from Datong, Taiyuan and Linfen. The experiment comprised three parts: adsorption-desorption, competitive adsorption and transport experiment. Soils for the adsorption experiment were sieved into the sand-sized fraction and clay-sized fraction. The main results indicate that at normal temperature and press the Hery model is more suitable for depicting the adsorption of Pb2+ by the sand-sized fraction and silt- and clay-sized fraction of the three types of soil. The adsorption experiment shows that soils have a very strong adsorption capacity and that CEC has an obvious effect on the adsorption process. In the competitive adsorption experiment, the presence of Pb reduces the adsorption of Cd by soils and humic acid can inhibit the adsorption of Cd by soils. The experiment of desorption shows that Pb in soils is mainly absorbed and is very difficult to desorb. The transport experiment indicates that after 20 days of leaching Pb2+ still failed to penetrate through the soil column, which suggests that soils have a very high capacity of Pb2+adsorption and that Pb was transported very slowly.