贵州煤矸石淋滤液污染区土壤重金属分布特征及污染评价

Distribution Characteristics and Pollution Assessment of Heavy Metals in Soil of Coal Gangue Leachate Polluted Area in Guizhou

摘要: 为探讨煤矸石淋滤液对土壤环境质量的影响，运用单因子指数法、内梅罗综合指数法、潜在生态风险指数法和地质累积指数法等对土壤中8种重金属元素(Cu、Zn、Cr、Ni、Cd、Pb、Hg、As)进行分析。结果表明，研究区表层土壤pH值在3.45~6.34之间，总体呈弱酸性，Cu、Zn、As、Cd、Cr、Ni超出农用地土壤污染风险筛选值(GB15618-2018)，且多种重金属元素含量超出背景值。土壤重金属单项生态风险表明，研究区土壤为中等生态危害，内梅罗综合污染指数显示有20%土壤样点达到重度污染水平，地质累积指数显示土壤环境为中度污染，潜在生态风险指数显示土壤生态系统受轻微损害，以Cu污染中严重，其次为Cd、Hg和Ni。

Abstract: In order to explore the effect of coal gangue leachate on soil environmental quality, the single-factor index method, Nemerow comprehensive index method, potential ecological risk index method and geological accumulation index method were used to measure the 8 kinds of heavy metal elements (Cu, Zn, Cr, Ni, Cd, Pb, Hg, As) in soil for analysis. The results show that the pH value of the surface soil in the study area is between 3.45 and 6.34, and the overall is weakly acidic. Cu, Zn, As, Cd, Cr and Ni exceed the soil pollution risk screening value of agricultural land (GB15618-2018), and the contents of several heavy metal elements exceed the background value. The single ecological risk of heavy metals in the soil shows that the soil in the study area is of moderate ecological hazard, the Nemerow comprehensive pollution index shows that 20% of the soil samples have reached the level of severe pollution, the geological accumulation index shows that the soil environment is moderately polluted, and the potential ecological risk index shows that the soil environment is moderately polluted. The ecosystem was slightly damaged, with Cu pollution being the most serious, followed by Cd, Hg and Ni.