Ecological risk assessment and pollution analysis on the heavy metals contaminated soil around Guixi smeltery

Three typical soil samples polluted by heavy metal were collected near the smelter and marked with no repair soil(A),under repairing soil(B)and the phytoremediated soil(C),the physical and chemical properties as well as the total heavy metals of the soils were determinated and analysed,and then assessed by the single pollution index and Nemerow pollution index,Hakanson index method was applied to ecaluate the heavy metals potential ecological risk.The results showed that:before soil phytoremediation comprehensive pollution index P=15.24,the soil belongs to high levels of pollution,with strong comprehensive hazard.6kinds of heavy metals Zn,Cd,Cu,As,Pb,Mo are accumulated in the soil with different degree,and the accumulate degrees of Cd、Cu、As is the most serious.Contention of Cr,Ni,Mn are lower than background values of the soil,which belongs to cleanness elements.After phytoremediation,all the heavy metal content are reduced,the comprehensive pollution index of soil P3,the comprehensive ecological potential harmfulness of soil is reduced significantly,which was in moderate pollution,Cd is still has a strong potential ecological risks,As with moderate potential ecological risk,Cu with minimal potential ecological risk.