金属矿区/冶炼场地环境风险扩散途径及其关键因子识别研究

Environmental Risk Diffusion Path and Key Factor Identification for Metal Mine and Smelter Area

以湖南省典型区域金属矿区/冶炼场地为例,基于文献爬取和案例场地调查,系统梳理和选取了影响场地重金属污染环境风险扩散途径的22个关键因子,利用内梅罗污染指数法计算场地土壤综合污染指数(NIPI)用以辅助识别关键因子。结果表明,基于层次分析法筛选得到的大气沉降和土壤渗透为场地重金属污染环境风险扩散关键途径,距污染源距离、空气中可吸入颗粒物含量(PM10)、地表硬覆盖情况、地下防渗措施、土壤酸碱度(pH值)和土壤有机质含量(SOM)为环境风险扩散途径关键因子。场地NIPI值与pH值、SOM、PM10等因子呈正相关关系,与距污染源距离、地表硬覆盖情况和地下防渗措施呈负相关关系,其相关系数与因子权重拟合效果较好(R2=0.63)。

A typical metal mine with a smelter in Hunan Province was taken as an example,and 22 key factors affecting the environmental risk diffusion path of heavy metal pollution area were chosen based on data crawling and on⁃site case investigation,as well as systematical sorting.Nemerow integrated pollution index(NIPI)of soil was calculated using Nemerow pollution index method,and then was used to aid the identification of key factors.Results show that atmospheric deposition and soil permeability are selected as the environmental risk diffusion path for heavy metal pollution of soil based on the analytic hierarchy process,and the key factors for environmental risk diffusion include distance from pollution source,PM10 content in air,hard cover on ground surface,anti⁃seepage measures,soil pH value and soil organic matter(SOM)content.It is found that the NIPI of the soil is positively correlated to soil pH value,SOM,PM10,but negatively correlated to the distance from pollution source,hard cover on soil surface and anti⁃seepage measures.The correlation coefficient fits well with the factor weight(R2=0.63).