Study On Environmental Chemical Action Of Cadmium In Topsoil In Chengdu

Cadmium in soil is harmful to environment and human health. Study on environmental chemical action of Cadmium in soil is helpful to prevent and eliminate the harm.Environmental chemical action of Cadmium in topsoil in Chengdu has been studied in this paper, including the Cadmium pollution survey of topsoil in Chengdu, the chemical speciation research of Cadmium in topsoil, the research of correlation between soil character and chemical speciation of Cadmium and eluviating experiment research.The results show that 42.86% topsoil samples are polluted by Cadmium, soil synthesis pollution index is moderate, Cadmium pollution degree of topsoil correlate with the environment of sampling sites. The results also show that exchangeable Cd, carbonate-bound Cd, organic-bound Cd and residual Cd are found in all soil samples except for Fe-Mn oxide-bound Cd. Furthermore, the concentration of exchangeable Cd and carbonate-bound Cd, both which have high biological validity, is high. Humus has a certain correlation with exchangeable Cd, organic-bound Cd and residual Cd, and has no obvious correlation with other chemical speciations. Any chemical speciation of Cd has no obvious correlation with pH and total Fe of soil samples. Cadmium in topsoil can be eluviated by acid solution, the quantity of Cadmium eluviated by redistilled water is little. With the rise of pH of eluviating solution, eluviated Cadmium quantity decrease. For the same soil sample, the lower pH value of eluviating solution is, the more fast the Cadmium is eluviated, and the more thequantity of Cadmium is eluviated.