Effects of Compaction and Initial Degree of Saturation on Contaminant Transport through Barrier

The effect of different degree of saturation and compaction on the diffusive properties of soil is studied. Change in the diffusion of nonreactive chloride (Cl⁻) through the barrier soil sample at different degree of saturation is experimentally obtained. Samples prepared at different densities and degrees of saturation are subjected to single reservoir diffusion testing for the determination of diffusion coefficient. Filter-paper method is used for obtaining soil-water characteristics curve (SWCC). Experimental results are used to calculate the values of diffusion coefficient by the method of curve fitting. The results show that for a particular density, the diffusion coefficient of the completely saturated sample is higher than that of unsaturated sample. However, when the samples are not fully saturated, rate of contaminant transport is less for the sample prepared at the higher water content. The results demonstrate the possible mechanism of transport of the contaminants in the soil when initial suction also adds to the mechanism.