【摘要】 针对上海典型化工企业场地(A)和金属制品企业场地(B),运用低成本的频率域电磁感应技术(FDEMI)进行全覆盖扫描探测,依据地层视电导率(ECa)空间分布特征,快速定位土壤/地下水疑似污染区,并合理布置钻孔取样点位。取样测试分析结果显示,土壤/地下水实际污染空间分布与地层ECa值平面分布高度一致。综合FDEMI全覆盖扫描和钻孔取样分析结果,采取"点面结合"方式对全场进行风险分级分区,确定了场地A的西北部及中部存在TPH、氯代芳烃、苯系物和重金属Mn的复合污染区,占全场总面积的28%;场地B的中部为重金属(Cr、Cu、Ni和Zn)重度污染区,占全场总面积的23%。土壤/地下水中重金属线性电导特性、污染物质极性、有机物自然降解过程中的离子释放现象等可能是引起地层ECa值空间变化的主要影响因素。更多还原

【Abstract】 One low-cost FDEMI(frequency domain electromagnetic induction) technology was applied to perform full-coverage site investigation at one site of relocated chemical enterprise(site A) and one site of metal product enterprise(site B) in Shanghai. Based on the spatial distribution characteristics of soil ECa(apparent electrical conductivity), FDEMI positioned efficiently the suspicious soil/groundwater contaminated areas of two sites, and helped to arrange reasonably the drilling sampling points. The results of lab analysis of soil and groundwater samples indicated that the spatial distribution of actual soil/groundwater contamination was highly consistent with the horizontal distribution of ECa values detected by FDEMI. The pollution risk mapping of the entire site was implemented by the combination of FDEMI scanning and drill-hole sampling, which was a diagnostic strategy of integrating point with surface. The northwest and middle parts of site(A) presented combined pollution with heavy metal(manganese), total petroleum hydrocarbons, chlorinated aromatic hydrocarbons, benzene series substances, accounting for 28% of the site’s total area. The central part of site(B) was heavily polluted by heavy metals(Cr, Cu, Ni and Zn), accounting for 23% of the site’s total area. The linear conductance characteristics of heavy metals, the polarity of pollutants, and the release of ions during the natural degradation of organic matter in soil/groundwater might be the main factors influencing the spatial variation of strata ECa values.更多还原