贵州惠水耕地土壤重金属污染调查与评价

    Investigation and evaluation of heavy metal pollution in cultivated land in Huishui County, Guizhou Province

    • 摘要: 为调查贵州省惠水县耕地土壤重金属污染现状, 采集了5013个表层土壤样品, 测定Cd、Hg、As、Pb、Cr、Cu、Ni、Zn含量和pH值, 选用单项污染指数法和地累积指数法对农作物-土壤重金属污染现状进行了评价, 并进行相关性分析和主成分分析。研究结果表明: ①土壤重金属元素As、Cd、Cr、Cu、Hg、Ni、Pb、Zn含量超标率分别为8.74%、34.51%、3.83%、0.56%、1.56%、0.24%、0.04%、1.60%, 其中Cd(k1=1.46)、Hg(k1=1.60)均值超过贵州省土壤A层背景值; ②单项污染物指数均值从小到大顺序为Cu(0.20) < Pb(0.22) < Ni(0.26) < Hg(0.27) < Zn(0.31) < Cr(0.44) < As(0.50) < Cd(1.70), 其中Cd、As的Pi均值较大; 重金属元素地累积指数均值从小到大顺序为Cu(-1.24) < Ni(-1.18) < As < Pb(-0.99) < Zn(-0.93) < Cr(-0.71) < Hg(-0.05) < Cd(0.04), Ig污染程度较高的为Cd和Hg; ③相关性分析表明As、Hg与其他6种重金属元素之间相关性较弱, 暗示具有不同来源特征; Cd与Cr、Ni、Pb、Zn相关性较强, 表明可能具有同源性; 主成分分析表明Cd、Pb、Zn、Cr、Ni来源于自然源与交通源, 主要受到上石炭统大铺组+黄龙组、下石炭统、上泥盆统革老河组+高坡场组地层与近SN向、EW向断裂构造的控制; Cu、Ni来源于农业因子与自然源; As和Hg来源于自然源与燃煤源。

       

      Abstract: This paper has collected 5013 surface soil samples to determine the contents of Cd, Hg, As, Pb, Cr, Cu, Ni, Zn, and pH values, and has chosen single factor pollution index method and ground accumulation index method to evaluate the status of heavy metal pollution in crop-soil and has carried out some correlation analysis and principal component analysis to study the current situation of heavy metal pollution in cultivated soil of Huishui County, Guizhou Province. The results show that: ①The excess rates of soil heavy metal elements As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were 8.74%, 34.51%, 3.83%, 0.56%, 1.56%, 0.24%, 0.04%, and 1.60% respectively. And the mean values of Cd(k1=1.46) and Hg(k1=1.60) exceeded the background values of soil layer A of Guizhou Province. ② The order of average individual Pi from small to large is presented as: Cu(0.20) < Pb(0.22) < Ni(0.26) < Hg(0.27) < Zn(0.31) < Cr(0.44) < As(0.50) < Cd(1.70), and the mean Pi of Cd and As was larger. The mean value of Ig of heavy metal elements from small to large is Cu(-1.24) < Ni(-1.18) < As, Pb(-0.99) < Zn(-0.93) < Cr(-0.71) < Hg(-0.05) < Cd(0.04), and Cd and Hg have higher Ig pollution degree. ③ The correlation analysis has showed that the correlations between As, Hg and the other six heavy metals are weak, which indicate that they have different sources while Cd is strongly correlated with Cr, Ni, Pb, and Zn, indicating that it may have homology. The principal component analysis shows that Cd, Pb, Zn, Cr, and Ni originated from natural and transportation sources, and were mainly controlled by upper Carboniferous Dapu Formation-Huanglong Formation(C1-2d+C2h), Lower Carboniferous(C1j+C1s+C1x+C1dw) and Upper Devonian Gelaohe-Gaopochang Formation(D3g+D3gp) and SN-trending and EW-trending faults. The Cu and Ni come from agricultural factors and natural sources, and the As and Hg come from natural sources and coal-burning sources.

       

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