浅析盐碱农田土壤重金属污染评价及其来源——以甘肃省酒泉市银达镇为例

The Evaluation of Heavy Metal Pollution in Saline-Alkali Farmland and Its Sources Were Analyzed—Taking Yinda Town, Jiuquan City, Gansu Province as an Example

为了解甘肃省酒泉市银达镇的盐碱农田土壤重金属的污染情况,采用“棋盘式”采样法采集土壤样品,运用X射线荧光光谱仪(XRF)并结合甘肃省土壤背景值对该区域农田进行调查和分析,对该区域农田重金属元素的含量测定并评估,分析其来源。结果表明采样区土壤中铜(Cu)、锌(Zn)、铬(Cr)、镍(Ni)、铅(Pb)、钴(Co)、汞(Hg)等7种重金属元素含量的平均值分别为3.70 mg/kg、155.87 mg/kg、32.24 mg/kg、21.88 mg/kg、204.12 mg/kg、2.42 mg/kg、0.87 mg/kg。上述金属元素除Cu、Cr、Ni、Co外,其余金属元素均不同程度超过甘肃省土壤背景值,采用单因子污染指数方法发现,研究区Cu、Ni、Cr、CO评估结果为无污染,Zn、Hg为中度污染,Pb为重度污染。内梅罗综合污染指数评估结果为重度污染,结果表明,Cu、Co、Ni元素的来源以天然因子为主,与土层中的组成及含量密切相关。Zn、Pb、Hg等金属的成因以人类活动为主。

To understand the town of Jiuquan city, Gansu province silver da salt of farmland soil heavy metal pollution, using “chessboard” sampling method to collect soil samples, using X-ray fluo-rescence spectrometer (XRF) and combined with the soil background value of Gansu province, the region, the content of the regional farmland heavy metal determination and evaluation, analysis of the source. The results show that the average value of copper (Cu), zinc (Zn), chro-mium (Cr), nickel (Ni), lead (Pb), cobalt (Co) and mercury (Hg) in the soil sampling area is 3.70 mg/kg, 155.87 mg/kg, 32.24 mg/kg, 21.88 mg/kg, 204.12 mg/kg, 2.42 mg/kg, 0.87 mg/kg. Ex-cept for Cu, Cr, Ni, and Co, the above metals exceeded the soil background value of Gansu Prov-ince to different degrees. The single-factor pollution index method was found that the assessment results of Cu, Ni, Cr, and CO in the study area were polluted, Zn and Hg were moderately polluted, and Pb was severely polluted. The evaluation result of the comprehensive pollution index was severe pollution, which showed that the sources of Cu, Co and Ni elements are mainly natural factors, which are closely related to the composition and content of the soil layer. Zn, Pb, Hg and other metals are mainly caused by human activities.