Physico-chemical and geo-environmental behavior of Semi Arid soils

Abstract

Soil is a basic building block for the most terrestric ecosystems and a complex heterogeneous medium consisting of both solid and fluid phases. Their physico-chemical characterization is of prime importance in understanding their prospective in various civil engineering applications. On the other hand, the ability of soils in absorbing and desorbing metal ions from the aqueous phase assumes importance since it governs both the environmental and agricultural issues. In this study, two different types of soils originating from diversified terrains of Saudi Arabia have been chosen and their potential application in various geotechnical and geo-environmental applications validated by carrying out typical characterization tests, including particle size distribution, density, shear and swelling characteristics. Further, in order to validate their potential applicability in typical landfill liners to retain toxic metal ions, their relative performance in retaining the heavy metal ions has been evaluated. Heavy metal ions such as copper and chromium were used to carry out sorption studies. Experimental data was used to plot adsorption isotherms. Langmuir isotherm was found to be more suitable than Freundlich isotherm for both the soils. It is observed both the soils, exhibited different physical and chemical characterization due to their difference in particle size gradations, as well as in mineralogy and surface morphology. Further, it is concluded that Al-Qatif soil can be used as a filter material and Al-Ghat soil as the main liner material to attenuate selected heavy metals, when they are used in the construction of a typical industrial landfill liner.