贵溪冶炼厂周边土壤重金属污染分析与生态风险评价

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

采集了贵溪冶炼厂附近3类典型重金属污染土壤:未受任何修复土壤(A)、正在进行植物修复的土壤(B)和已受植物修复的土壤(C),测定和分析了土壤的理化性质和重金属总量,采用单因子污染指数法和内梅罗综合指数法对该土壤进行了评价,Hakanson潜在生态风险评价法评估了该土壤中重金属的潜在生态危害。结果表明:修复前,土壤综合污染指数P综=15.24,土壤属重度污染,具有极强的综合危害性;Zn、Cd、Cu、As、Pb、Mo 6种重金属都有不同程度的积累,其中Cd、Cu、As 3种重金属的积累程度最为严重;Cr、Ni、Mn含量低于土壤背景值,属清洁元素。修复后,各重金属含量均有所降低,土壤综合污染指数P综<3,土壤的综合潜在生态危害性大大降低,土壤为中度污染,但Cd仍具有很强的潜在生态风险,As存在中度潜在生态风险,Cu存在轻度潜在生态风险。

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 P<3,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.