关键词: 沉积物, 毒害重金属, 生态效应, 分布

Abstract: Distribution and characteristics of heavy metals(Hg、Cd、Cu、Pb、Zn、As、Cr、Ni) in sediment columns from six lakes in Wuhan were investigated. The results demonstrated that the concentrations of heavy metals in lakes in urban area are invariably higher than sediments from lakes in suburb area, and the concentration of heavy metals in top sediment of the urban polluted lakes show some degree of accumulation when compared with deeper sediments in lake sediment columns, while heavy metals show no significant change among sediment columns in suburb lakes. Potential ecological risk index and fresh water sediment quality criteria were then used to assess the heavy metals ecological risk, which leld us to conclude that the potential risk order of elements were Cd> Hg> As> Cu> Pb>Zn; Moshu Lake is of the highest potential risk, Jinying Lake ranks the second, while the others have relatively small risk. But, overall, the potential ecological risk of investigated lakes in Wuhan is light, at least not very serious. With reference to the threshold obtained by Canadian ecological databank of sediment baseline, heavy metals in sediments of some lakes of relatively higher risk index may press negative effects to biota within the lake.

Key words: sediment columns, heavy metals, ecological risk distribution