济南市洪范池地区土壤重金属地球化学特征与潜在生态风险评价

Geochemical Characteristics and Potential Ecological Risk Assessment of Heavy Metals in Topsoil of Hongfanchi Area in Ji'nan City

摘要:

为研究济南市洪范池地区表层土壤重金属地球化学特征，分析其影响因素，评价其潜在生态风险水平，在研究区进行了大比例尺土壤地球化学测量，分析了8种重金属元素的含量，对其地球化学数据特征进行了多元统计分析，利用潜在生态风险指数法进行了风险评价。研究表明，As、Cd、Cr、Cu、Ni、Pb、Zn 7种元素含量与背景值接近，具有较小的变异系数和类似的空间分布特征，成土母质是控制其在表层土壤中分布的主要因素；Hg元素的平均含量明显高于背景值，具有较大的变异系数和截然不同的空间分布特征，其在表层土壤中的分布人类活动的影响较为明显。As、Cr、Cu、Ni、Pb、Zn 6种重金属均表现为轻微生态风险水平；Cd在大部分采样点表现为轻微生态风险的水平；Hg表现了最高的潜在生态风险。研究区土壤总体状况较好，主要污染因子为Cr和Hg。

Abstract:

In order to study geochemical characteristics of heavy metals in topsoil of Hongfanchi area in Ji'nan city, analyze their influencing factors, evaluate their potential ecological risk level, largescale soil geochemical measurements have been conducted in the study area. The contents of 8 heavy metal elements have been analyzed. Multivariate statistical analysis on characteristics of geochemical data have been conducted. The potential ecological risk index method has been used for risk assessment. It is showed that the contents of seven elements, such as As, Cd, Cr, Cu, Ni, Pb and Zn are close to the background values, with small coefficients of variation and similar spatial distribution characteristics. The parent material of the soil is main factor controlling their distribution in the surface soil. The average content of Hg element is significantly higher than the background value, with a large coefficient of variation and distinct spatial distribution characteristics. Its distribution in the surface soil has been significantly influenced by human activities. The six heavy metals of As, Cr, Cu, Ni, Pb and Zn in the surface soil show a slight ecological risk level, Cd shows a slight ecological risk level in most sampling points, and Hg exhibits the highest potential ecological risk. The overall soil condition in the study area is good, and main pollutants are Cr and Hg.