Partition characteristics and correlation of heavy metal between sediment and surface water from Chaohu Lake

Twenty seven samples of water and sediment were collected in the three main estuaries (Nanfei River, Yuxi River, and Hangbu River) of Chaohu Lake respectively. The heavy metal（Cd, Cr, Cu, Pb, Zn, As, Hg）contents in the sediment and the dissolved contents in the water were tested with precision instruments such as ICP-OES and AFS, partition coefficients between sediment and surface water were calculated, and any correlation between two elements was analyzed for each estaury. Physical and chemical analysis of water quality indicated that the contents of TN and TP are higher than the limits of the Class Ⅴ environmental quality standard in the rivers. The results of element test showed that the contents of heavy metal elements except mercury are lower than Class Ⅰenvironmental quality standard basically while sediment contents exceed the background values for a great number of sediment samples. The pollution is most serious at the entrance of Nanfei River, partiton coefficients of element Cr, Cu, Pb, Zn and As are lower than those of the others. However, the partition coefficents of heavy metal Cd and Hg are lowest in the Hangbu River, and there is good correlation among the 3 elements of Cu,Cd and Hg.