| Previous research has shown that the dielectric constant and electrical conductivity of the soil-fluid (water) system can be used to determine some of soil properties such as moisture content and porosity. Also, previous research has shown that as the dielectric constant of the pore fluid decreases the hydraulic conductivity of soil-fluid system increases due to variations in soil structure. One of the objectives of this study is to investigate the possibility of using the dielectric constant and electric conductivity to characterize and identify contaminated fine-grained soils. The other objective is to determine the effect of selected organic liquids on selected physico-chemical parameters such as Atterberg limits, cation exchange capacity, CEC, zeta potential, pore size distribution of fine-grained soils.;To investigate the usefulness of the concept of dielectric constant and electrical conductivity to characterize contaminated fine-grained soils, the dielectric constant and electrical conductivity of kaolinite, bentonite and local soil are determined at various ion concentrations, and organic liquids moisture content. Results show that both the dielectric constant and electrical conductivity of a soil-fluid system is mainly controlled by that of pore fluid. In the case of water, the dielectric constant decreases as ionic concentration increases at high frequencies (MHz range), reverse is true at low frequencies (kHz).;To determine the effect of the organic liquids on the selected physico-chemical parameters: Atterberg limits, cation exchange capacity (CEC), zeta potential, surface charge density, pore size distribution of kaolinite, bentonite and local soil are determined. Results show that as the dielectric constant of the organic liquids decreases, the physico-chemical parameters of soils vary considerably as compared to those of water. Results also show that as the pore fluid changes, the attractive and repulsive forces between soil particles and soil particles and pore fluid changes significantly.;To fully understand the nature of fine-grained soil-pore fluid interaction, the work of adhesion is determined by means of measuring soil-liquid contact angle by the Wilhelmy plate technique. Results reveal that work of adhesion of soils with liquids varies considerably depending on the surface tension of organic liquids (cohesion) as well as the liquid-soil adhesive forces. |
