Experimental investigation of correlations between electrical resistivity, moisture content and voltage values for leachate contaminated clayey sand

Abstract Leachate leakage from landfill sites has become a significant environmental problem in recent years, polluting soil layers and groundwater aquifers. A considerable number of dumpsites near cities are operated traditionally and are not designed as landfills, which increases the risk of leakage. Leachate leakage also changes geotechnical and geo-environmental characteristics of soil, often increases soil permeability. Geo-electrical methods are one of the most common methods in leachate leakage investigation in recent years, which are considered as non-destructive methods. Despite recent studies, there are still challenges in applying geo-electrical methods to study leachate leaking from landfill sites that can be addressed through small-scale laboratory studies. One of the critical parameters in the laboratory study of soil resistivity is the voltage of current injected into the soil sample. In this research, the effect of voltage changes applied to the soil samples contaminated by solutions with different contaminant concentrations was investigated. Also, the relation between soil moisture content and resistivity was studied. It was found that there was a sudden change in the reduction rate of soil resistivity for moisture content larger than 13%, which is equal to soil plastic limit. The results showed that by increasing the voltage injected into the soil sample, fluctuation of resistivity values decreased and the transparency of the results increased.