Abstract:

       The total contents of heavey metal elements in the bed mud from 0 to 20 cm were investigated in the Wuliangsu lake, and the risk of heavy metal pollution was evaluated using ecology risk harm index method. According to the state standard of ocean sediment quality (first level), threshold effective level and state standard of soil quality (first level), the combined pollutions of heavy metal element from the bed mud of the Wuliangsu lake are relatively serious,and the main pollutant elements are Cu, Cd, Ni and Zn. There are a remarkable correlation between the total contents of Pb, Cd, As, Cu, Cr, Hg and Zn, which suggests a same origin of pollutants. Evaluation results of ecological risk index method show that the most parts of the lake belong to a mild pollution risk; three entrances of drainage irrigation channels belong to extreme sever pollutions risk;and other areas belong to severe pollution.

Key words: bed mud, heavy metal pollution, potential pollution risk, Wuliangsu lake, Inner Mongolia