| After field survey, we collected in51surface soil samples around Pingwei generating plant. After the soil samples had been digested, heavy metals were determined by flame atomic absorption spectrometry. And the data were processed by SPSS, Origin and other softwares. In this paper, the environmental geochemistry of Co, Cr, Cu, Mn, Ni, Pb, Zn and Hg in soil around Pingwei generating plant was detailed study. The geochemical baselines of these8kings of heavy metals were determined. Thus the geochemical indicators discriminating natural and man-made impact on heavy metals in soil surface around the plants were established. And the Cumulative Index of Geology (Igeo), Contamination Degree (CD) and Pollution Levels Index (PIL) of these heavy metals from study area were calculated based on the geochemical baselines. The environmental geochemical analysis was made based on these indicators of heavy metals in surface soil around Pingwei generating plant. The conclusions were as follows.(1) The minimum value of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is14.45mg/kg,32.14mg/kg,30.49mg/kg,217.59mg/kg,5.71mg/kg,7.80mg/kg,37.91mg/kg,0.0003mg/kg, respectively; The maximal value of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is23.38mg/kg,150.01mg/kg,4.60mg/kg,479.63mg/kg,15.83mg/kg,11.92mg/kg,166.65mg/kg,0.3007mg/kg, respectively; The mean of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is18.47mg/kg,89.64mg/kg,18.69mg/kg,362.68mg/kg,10.06mg/kg,9.28mg/kg,70.59mg/kg,0.0193mg/kg, respectively; The Coefficient of variation of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is10.44%,40.47%,30.53%,17.37%,22.82%,9.51%,27.70%,237.01%.(2)There are significant correlations between Cu and Co, Mn and Co, Ni and Co, Ni and Mn, Pb and Ni, Zn and Co, Zn and Cr, Zn and Cu, Zn and Mn, Hg and Mn, Hg and Ni,which means the heavy metals with significant correlation may have the same source。(3) The average content of Cr is above soil background value of Huainan city, while the content of Cu, Mn, Ni, Pb and Zn is below corresponding soil background value of Huainan city. (4) Taking Fe as normalized factor, the environmental geochemistry baseline of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is18.62mg/kg,88.70mg/kg,18.25mg/kg,385.69mg/kg,10.13mg/kg,9.26mg/kg,68.57mg/kg and0.0743mg/kg, respectively。(5) The environmental geochemistry baseline of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is,16.65mg/kg,57.50mg/kg,16.09mg/kg,302.95mg/kg,8.66mg/kg,9.09mg/kg,59.08mg/kg,0.0361mg/kg, respectively, using statistical method. In this sudy area, the geochemistry baseline determined using statistical method is below the one determined using normalized method.(6) The average of baselines determined using statistical method and normalized method is taken as the environmental geochemistry baseline of heavy metals in surface soil from study area. So the environmental geochemistry baseline of Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg in surface soil from study area is17.64mg/kg,73.10mg/kg,17.17mg/kg,344.32mg/kg,9.40mg/kg,9.18mg/kg,63.83mg/k,0.0552mg/kg, respectively.(7) Cumulative Index of Geology is an important method to evaluate soil heavy metal pollution. The value is bigger, and the pollution level is higher. Except the average of Igeo of Hg is below0, the average of Igeo of Cu, Mn, Ni, Pb and Zn is above0belonging to grade1and grade2. Only individual element or individual site belonging to grade3and grade4is moderately or strongly polluted. The study area is not or slightly polluted by heavy metals. The subsequence of pollution levels of heavy metalsi in surface soil around Pingwei generating plant is Cr>Zn>Ni>Co>Mn>Cu>Pb>Hg.(8)Except the average of CD of Hg is below0, the average of CD of Cu, Mn, Ni, Pb and Zn is above0and below1, belonging to grade1and grade2. Only individual element or individual site is above moderately polluted, the study area is not or slightly polluted to moderately polluted by heavy metals. The subsequence of pollution levels of heavy metalsi in surface soil around Pingwei generating plant is Cr>Zn> Cu> Ni>Mn> Co>Pb>Hg.(9) Except Hg, the PIL of Cu, Mn, Ni, Pb and Zn rangs from lto2,which means the surface soil is moderately polluted. The area PIL of Co, Cr, Cu, Mn, Ni, Pb, Zn is1.05, which means the surface soil is moderately polluted. Figures [46] Tables [17] References [118]... |
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