汾河河道及滩地铅镉汞分布特征研究

Study on the Distribution of Pb,Cd and Hg in Fenhe River Channel and Its Floodplain

选取能够代表汾河特征的断面,在对汾河主要重金属污染元素铅、镉、汞在河槽底泥及滩地土层中积累量进行实测的基础上,分析了汾河河道及滩地中重金属的分布规律及其机理。结果表明:汾河下游表层土中重金属铅、镉、汞的含量最低,中游和入黄口处略高,但都高于山西省土壤重金属元素背景值;在所选断面的水平方向上,位于河槽内、在河床与水面线交接处的取样点的表层土中重金属铅、镉、汞含量低于位于近河滩地的,且铅、镉的含量随着距离河道主槽水平距离的增加而减小;在纵向分布上,重金属铅、镉、汞属于表层富集型的分布类型,即随着土层深度的增加,铅、镉、汞含量呈下降趋势。

Chosen three typical sections that characterize Fenhe River and the main heavy metals contamination of Pb,Cd and Hg in Fenhe River,based on the test results of heavy metals accumulation in sediment and floodplain,the space distribution law and mechanism of heavy metals were analyzed. The results show that the contents of Pb,Cd and Hg in the topsoil of Fenhe River downstream are lower than that of the midstream and outfall along the river. Their contents are greater than their background values of Shanxi Province. In the horizontal,their contents in sample point within the channel,in the river bed and the water line are lower than that of the sample point in floodplain and the contents of Pb and Cd decreases with the increase of distance from the river main channel. In the vertical,Pb,Cd and Hg have a tendency of descending with the depth of soil increasing.