矿区周边农田土壤重金属分布特征及污染评价

为探索潼关矿区周边农田土壤重金属的空间分布及其生态风险，于2020年9月采集了潼关矿区周边的地表土壤样本，分析了样本中Pb、 Cu、 Cd、 Hg、 Cr、 Ni、 Zn和As这8种重金属元素的含量和分布特征，利用内梅罗综合污染指数和潜在生态风险指数评价了土壤污染程度.结果表明，该地区8种重金属元素的含量均超标，超标率分别为97.91%、 84.79%、 100%、 95.41%、 96.87%、 98.54%、 91.45%和28.95%. 8种重金属元素的变异系数大小为：Hg>Pb>Cu>Cd>Zn>As>Ni>Cr,其中Hg、 Pb、 Cu、 Cd和Zn的变异系数均大于1,相关性分析表明这5种重金属相关性明显；在空间分布上，土壤重金属中Pb、 Cd、 Cu、 Hg、 Zn和As这6种元素呈斑块状分布，Cr和Ni呈片状分布，Hg、 Cd、 Pb、 Cu和Zn这5种重金属元素的高值主要分布在研究区南部和中部；内梅罗综合污染指数显示重度污染率达到87.91%,中度污染率和轻度污染率分别为9.58%和2.5%,因此整体处于重度污染.潜在生态风险指...

Distribution Characteristics of Heavy Metals in Farmland Soils Around Mining Areas and Pollution Assessment

In order to explore the spatial distribution and ecological risk of heavy metals in farmland soil around Tongguan Mining area, surface soil samples from Tongguan Mining area were collected in September 2020, and the contents and distribution characteristics of eight heavy metals (Pb, Cu, Cd, Hg, Cr, Ni, Zn, and As) in the samples were analyzed. The Nemerow comprehensive pollution index and potential ecological risk index were used to evaluate soil pollution. The results showed that the contents of the eight types of heavy metal elements in this area exceeded the standard, and the exceeding rates were 97.91%, 84.79%, 100%, 95.41%, 96.87%, 98.54%, 91.45%, and 28.95%, respectively. The variation coefficients of the eight heavy metals were ranked as Hg>Pb>Cu>Cd>Zn>As>Ni>Cr. The variation coefficients of Hg, Pb, Cu, Cd, and Zn were all greater than 1. Correlation analysis showed that these five heavy metals were obviously correlated. In terms of spatial distribution, Pb, Cd, Cu, Hg, Zn, and As were distributed in patches, whereas Cr and Ni were distributed in flakes. The high values of Hg, Cd, Pb, Cu, and Zn were mainly distributed in the southern and central part of the study area. The comprehensive pollution of Nemerow showed that the severe pollution rate reached 87.91%, and the moderate pollution rate and the mild pollution rate were 9.58% and 2.5%, respectively; thus, the overall pollution was severe. The potential ecological risk index showed that Hg, Cd, Pb, and Cu were the main risk elements. The total potential ecological risk index showed that the proportion of samples with strong pollution was 97.08%, and the proportion of extremely strongly, very strongly, and strongly polluted samples were 55.63%, 27.08%, and 14.37%, respectively, indicating that the overall potential ecological risk in the study area was very strong. Combining the two pollution assessment methods, it can be seen that the heavy metal pollution around Tongguan mining area, primarily by Hg, Cd, and Pb, was serious. These results can provide data support for regional pollution control, soil remediation, and ecological protection. It is suggested that the state of soil heavy metal pollution and its transformation in various media should be monitored continuously in the future.