Potential ecological risk assessment of heavy metal pollution in surface sediment of the Dahuofang reservoir

The Dahuofang reservoir is a typical drinking water source in the Liaohe River basin. However, the heavy metal pollution is an important problem for the Dahuofang reservoir due to waste water discharges from the surround industrial enterprises. The contents and distribution of the heavy metal in the surface sediment of reservoir such as Cr, Cu, Zn, Cd and Pb were analyzed by a Hakanson potential ecological risk index method in order to study pollution situation. The pollution extent and potential ecological risk were evaluated, and the evaluation results were tested by a geoaccumulation index method. The results indicate that Cd is the primary pollution element of potential ecological risk in surface sediment of the Dahuofang reservoir. The ecological risk order of five pollution elements is as follows: Cd>Cu>Pb>Cr>Zn.