镍钼多金属矿区土壤铀污染状况及来源分析

Contamination degree and source of Uranium in soils around the Ni-Mo polymetallic mining area

为了解遵义松林镍钼多金属矿区土壤重金属铀(U)污染状况,采集矿区旱地、水稻土和森林土壤样品,采用ICP-MS测定土壤中U含量,运用单因子指数和地质累积指数法,评价矿区重金属的污染状况。结果表明:1)矿区旱地、水稻土和森林土壤中U平均含量分别为14.7 mg·kg^-1、 8.67 mg·kg^-1和16.5 mg·kg^-1, 3种类型土壤中U含量均高于贵州省土壤背景值;2)单因子指数评价结果表明,旱地、水稻土和森林土壤均受到不同程度污染,旱地污染程度较轻,水稻土主要集中在轻度污染,森林土为中度污染和重度污染;3)地质累积指数评价结果表明,研究区旱地、水稻土和森林土壤污染程度主要集中在轻度污染等级,分别占样品数的48%、 67%和58%,其中森林土壤有42%的样品为中度污染,受地质背景影响较大。

In order to understand the contamination degree of Uranium in soils around the Ni-Mo polymetallic mining area in Songlin, Zunyi,Guizhou. The dry soil, paddy soil and forest soil samples were collected from the mining area. The U content in the soil was determined by ICP-MS and the single factor index and geoaccumulation index method were used to evaluate the pollution degree of heavy metals. The results of the study show that: 1)The averaged Uranium content in dryland soil, paddy soil and forest soil from the mining area are 14.7 mg·kg^-1、 8.67 mg·kg^-1 and 16.5 mg·kg^-1 respectively;the contents of Uranium in the three types of soil are higher than the corresponding background value of the soil in Guizhou;2)The assessment results by single factor index method indicate that dryland soil, paddy soil and forest soil were polluted by Uranium, the dry land and paddy soil were mainly light polluted, the forest soil was moderate polluted and heavy polluted. 3)The evaluation results of the geoaccumulation index indicate that the pollution degree of dry land, paddy soil and forest soil is mainly moderate polluted, accounting for 48%, 67% and 58% of the sample respectively, of which, 42% of the forest soils is moderately polluted,it is few affected by geological background.