Abstract:

The fraction distribution of heavy metals is the key parameter of its environment effects. In this article, form distribution characteristic of soil heavy metals (Cr, Cu, Pb)and its influencing factors were investigated in Nanhu ecological park in Tangshan. A total of 20 soil samples were collected and analyzed. Using BCR(European Community Bureau of Reference) sequential extraction procedure, four fractions of soil heavy metals, weak acid soluble fraction, reducible fraction, organic matter fraction and residual fraction, were extracted in the topsoil(0-20 cm)，and its influencing factors were studied by correlation analysis. The results showed that Cr and Cu were dominated mainly by the fraction of residual fraction and weak acid soluble fraction, while Pb was existed by the fraction of residual Pb and reducible Pb; Only Cr indicated some potential environmental risks, because of its higher values in weak acid soluble forms. Correlation analysis indicated the soil pH value had very significantly negative correlation with the heavy mental weak acid soluble forms, very significantly positive correlation with the reducible fraction of Cu and Zn. The content of soil organic matter had very significantly positive correlation with the organic forms of Cu and Pb. In the process of ecological park construction, the environmental risks can reduce though out reduce weak acid soluble fraction of heavy mental, which can achieve by raising soil pH slightly.