河道底泥重金属污染及农用潜在风险评价

以辽宁省沈阳市细河河道底泥为研究对象,采用地累积指数法、变异系数法和潜在生态危害指数法对底泥中重金属污染状况及底泥农用进行风险评价。结果表明,河道底泥重金属污染严重,Cu、Cd、Pb和Cr的平均含量分别为319.68、16.08、18.20和155.09mg/kg,均超过辽宁省土壤背景值,Cu、Cd含量超过污泥农用控制标准;底泥重金属富集程度为Cd〉Cu〉Cr〉Pb,其中Cd富集程度达6级,为严重污染,重金属Cu和Pb的变异系数较大;以辽宁省土壤背景值作为参比值进行评价,细河处于严重的潜在生态危害程度,4种重金属的生态危害顺序为Cd〉Cu〉Pb〉Cr,细河河道底泥农用存在严重风险。

Heavy Metal Pollution of River Sediment and Potential Risk Assessment for Agricultural Utilization

The river sediment of Xihe in Shenyang City of Liaoning Province was studied to evaluate the contamination status of heavy metals,and make risk assessment for agricultural utilization based on the Geo-accumulation index,variation coefficient and potential ecological risk index.The results showed,the sediment was severely polluted by heavy metals,the average content of Cu,Cd,Pb and Cr were 319.68,16.08,18.20 and 155.09 mg/kg respectively,which were higher than the background soil values in Liaoning Province.The content of Cu and Pb exceed the control standard for agricultural utilization.The heavy metals were enriched in the order:Cd>Cu>Cr>Pb.The pollution of Cd reached grade 6,the most serious pollution degree.The variation coefficients of Cu and Pb were big.Compared to soil background values of Liaoning Province,the heavy metals in Xihe showed very serious ecological risk,and the order of potential ecological risk of the four heavy metals was Cd>Cu>Pb>Cr,it is serious for sediment of Xihe river to make the agricultural utilization.