Research on Pollution Characteristics of Nutriment Elements and Heavy Metals in Sediment of Lake Kuncheng

The vertical distributions of nutriment elements(TN,TP and TOC) and heavy metals(Pb,Cu,Zn,Cd,Cr) in the columnar sediments of 9 sampling sites in Lake Kuncheng were determined.The results showed that the contents of all the elements lowered continuously with the increase of the sediment depth.The environmental behavior of TOC was similar to TN's,which accounts for that the aggrandizement of TN is accompanied by the organic substances;there was a positive correlation between TOC and heavy metals,which indicated that the pollution of heavy metals was disturbed markedly by human beings.The organic substances in the sediments had obvious dual sources.By evaluating the sediments,it showed that organic pollution of the lake was in the state of clear and less clear,and the results of index of geo-accumulation(I_(geo)) evaluation showed that pollution mainly focused on the surface and the dominant contaminant was Zn,and there were basically no pollution of Cd and Cr.