Vertical Distribution of the Heavy Metals in Maixi River Sediments and Its Potential Ecological Risk

In order to reveal the heavy metal pollution in sediments from Maixi River in Baihua Lake,and provide a scientific basis for the prevention of heavy metals,Vertical distribution and characteristics of heavy metals(Hg,Cd,Cu,Zn,Pb,As) were investigated after collecting columnar sediment samples using SWB-1 bottom sampler.Meanwhile,the potential ecological risk of six heavy metals were assessed with Hakanson pontential ecological risk index.The results showed that the overproof contents of heavy metals were different according to different standards.According to the soil environmental quality standards,the order of heavy metals content arrangement was HgCuCdZnAsPb.Using the average content of heavy metal in sediments of Chinese lakes,the order of arrangement was HgCuZnAs CdPb and according to the soil values of Guiyang City,the order was HgCdCuZnPbAs.Hg pollution was the most serious no matter what standard was used.With the change of the depth and times of the sediments,the vertical distribution characteristics of Hg content increased first and then decreased,but the change of other five heavy metals content was relatively smooth.The order of ecological risk Eir was HgCdCuAsPbZn and RI was 392.35,reaching a high level.All above showed that the degree of the heavy metals potential ecological risk was serious in sediments from Maixi River in Baihua Lake.