The analysis and pollution assessment of heavy metals in the sediment of the East River

The concentrations of Pb,Zn,Cu,Cd,Cr and Ni in the sediment and the sediment elutriate samples from different sites of Dongjiang River were analyzed.The results indicate high Pb and Cd content,suggesting certain degree of pollution or high background value in the sediment.The contamination of Zn,Cu,Cr and Ni in the sediment may be from the same source.Using the geoaccumulation index of Muller and the potential ecological risk index of Hakanson,the data show that the pollution of Cd is severe,and its potential ecological risk is high.The extent of risk ranks as CdCuZnNi,and there is hardly any pollution caused by Pb and Cr.However,Pb has potential ecological risk.The concentration of heavy metals in the sediment and sediment elutriate is correlated,indzcating that the sediment is the key source of heavy metals in surface water.