Heavy Metal Pollution of the Sediment in the Mainstream of Huaihe River and Assessment of Its Potential Ecological Risk

To investigate status quo of heavy metal pollution of the sediments in the main stream of Huaihe River, a total of 12 sampling sections were set up along the section typical of the main-stream of Huaihe River, and 3-5 sampling points in each sampling section. Samples of surface sediments were collected at each sampling point for analysis of acid-volatile sulfide (AVS), simultaneously extracted metals (SEM), total organic carbon (TOC), particle size distribution and total heavy metals (As, Cd, Cr, Cu, Pb and Zn). And then ecological risk assessment of the heavy metals in the sediments was performed with the equilibrium partitioning model (EqP Model) and the potential ecological hazard index method. Results show that Cd in all the sampling sections reached the severe hazard level, while As, Cr, Cu, Pb and Zn were at the mild ecological hazard level. In terms of potential ecological risk of a single element, the heavy metals follow an order of Cd > As > Cu > Pb > Cr > Zn. Analysis with the EqP Model shows that in the sections of Linhuaiguan, Fengtaidaqiao, Funanwangjiaba, Lutaizi, Xiaoliuxiang and Xuyishuiwenzhan, heavy metal pollution of the sediments has not yet reached the level of potential biological toxicity while in the sections of Huaibingudui, Laobatou, Huainandajiangou, Matoucheng, Bengbuzhashang and Bengbuwujiadu. To sum up, heavy metal pollution varies in level from section to section along the river, which should arouse enough attention from related government departments.