丹江口水库新增淹没区农田土壤重金属生态危害评价

为研究丹江口水库新增淹没区农田土壤重金属污染状况,通过野外调查,采集169个土壤样品,分析了土壤中7种重金属(Cr、Cd、Pb、Ni、Zn、Cu、As)的污染特征和空间分布,并采用Igeo(地质累积指数)法对土壤重金属进行生态危害评价.结果表明:w(Cr)低于河南省土壤环境背景值,w(Cd)、w(Pb)、w(Ni)、w(Cu)、w(As)、w(Zn)均高于河南省土壤环境背景值,其中,w(Cr)比河南省土壤环境背景值低18.90 mg/kg,w(Zn)比河南省土壤环境背景值高11.21 mg/kg,w(Cd)则为河南省土壤环境背景值的16倍.空间分析表明,河南省淅川县、湖北省丹江口市附近的库区以及河南省九重镇、盛湾镇库周的土壤重金属质量分数较高,而其余区域较低;Igeo法评价结果表明,Cd是丹江口水库新增淹没区主要的污染元素,Cr、Pb、Ni、Zn、Cu、As则处于无污染水平.

Ecological Risk Assessment of Heavy Metals in Farmland Soil from New Submerged Area around Danjiangkou Reservoir

Abstract: The concentrations and pollution characteristics of Cr, Cd, Pb, Ni, Zn, Cu and As in the farmland soil from submerged areas in Danjiangkou Reservoir were explored through field investigation, in which 169 soil samples from the farmland area were obtained. Ecological risk index method was applied to assess the ecological risk of heavy metals. The results indicated that the content of Cr was lower than the environmental background values of Henan Province, and the concentrations of the other elements were higher than their environmental background values. Compared with the environment background values of Henan Province, the content of Cr was less than 18.90 mg/kg, and the content of Zn was more than 11.21 mg/kg. The concentration of Cd was 16 times greater than the environmental background values of Henan Province. The results of spatial analysis technology showed that the high soil heavy metals were distributed in the submerged area of Xichuan Country, Danjiangkou City, Qiuchong Town and Shengwan Town of Henan Province. Cd was the major contaminated element in the new submerged area in the Danjiangkou Reservoir, while the pollution levels of Cr, Zn, Pb, Ni, Cu and As were classified as not polluted.