Distribution, Speciation and Ecological Risk Assessment of Heavy Metals in the Surface Sediments of Sanmen Bay in ZheJiang

Abstract

Abstract. This Surface sediment samples were collected from Sanmen Bay in Zhejiang. The distribution of total concentration of five heavy metals (Zinc, Chromium, Cadmium, Copper, and Lead) was determined, and their speciation using BCR sequential extraction procedure was investigated. The pollution level and ecological hazard of these heavy metals were evaluated Potential Ecological Risk Index (Er i ). The distribution of five metals showed that the total concentrations in inner bay were higher than those in out of bay. The results of metal speciation in surface sediment show that the residual fraction of four metal except for Pb predominated, of which Zn account for 79.20%~84.25%, Cr 93.24%~96.16%, Cd 34.71%~57.58%, and Cu 66.06%~79.51%, respectively. The dominate fraction of Pb is the part bounded to amorphous Fe and Mn oxides and hydroxides, which accounts for 58.17%~72.7%. The evaluation results indicate that Cd is the primary element with slight ecological risk in the area according to the potential ecological risk index (Er i ).