垃圾填埋场污染土的电性与磁性响应研究

以武汉市二妃山垃圾填埋场为研究对象,运用污染土的电性、磁学以及地球化学等分析手段,借助多元统计方法,研究土壤剖面电性、磁学参数与元素含量之间的关系,探讨土壤电阻率法和环境磁学方法在城镇垃圾填埋场污染土快速监测中应用的可行性.研究表明,电磁法测深技术可获得污染土壤地层的垂向电阻率分布情况,污染后的地层电阻率呈现阶梯变化,具有明显分层现象.说明了电阻率法在污染区域划分具有一定的可能性.根据电阻率垂向特征,对剖面进行了环境磁学和重金属分析的样品采集和测定分析,发现土壤的磁学参数与电阻率、重金属含量具有良好的一致性.污染后土壤具有电阻率减小,磁化率增大,重金属含量升高等特点,证明了电阻率和磁化率都能较好反映出土壤的污染程度.污染土典型样品的热磁曲线表明,污染后的土壤比未受污染的土壤含有更多的铁磁性矿物.由此表明利用土壤电性和磁性对污染程度的指示作用都具有良好的响应,可替代繁琐的重金属检测.

The study of electric and magnetic response on polluted soil at waste landfill.

The feasibility of rapidly testing contaminated soils at refuse landfill as an example of Erfeishan in the skirt of Wuhan city, using soil resistivity and environmental magnetism methods, had been discussed, in terms of analytic techniques for contaminated soils, such as electric, magnetic and geochemical to study cross-section soil conductivity, the relationship between magnetic parameters and element content. Depth sounding with electromagnetic (EM) could give the vertical resistivity distribution image of soil cross-section, which indicated that the resistivity of polluted soils vary in stepped pattern, having obvious layered phenomenon. Resistivity method was capable of dividing the boundary of polluted area. Based on the characteristic of vertical resistivity distribution at cross-section, the environmental magnetism and heavy metal of the specimens sampled along the cross-section were analyzed, which shows that the magnetism parameters, resistivity value and heavy metals content have prominent accordance. The contaminated soils had the features of low resistivity, high susceptibility and increasing heavy metal content. Resistivity and susceptibility could all perfectly reflect the polluted degree in the area. Also from the thermal magnetism analytic curves, the polluted soils had more ferromagnetic minerals than non-polluted soils. So, both soil conductivity and magnetism had good response to soil polluted degree, which could replace the tedious conditional heavy metal testing methods.