laboratory simulation of one and two dimensional contaminant transport by pure diffusion underneath a solid waste landfill

one and two dimensional contaminant transport by pure diffusion through single layer of fine grained soil was investigated using one and two dimensional laboratory models. these models simulates a simple hydrogeologic situation underneath a solid waste landfill comprising a fine grained soil overlying a bed rock. sodium chloride solution was sued as a contaminant source above a compacted clayey soil. during the tests samples were taken from the source solution above the soil sample and the chloride concentration change with time was observed. at the end of the tests the soil sample was sliced and the concentration profile was abtained through the soil layer. then using the theoretical models the observed data was compared with the theoretical predictions and the diffusion coefficient of chloride at the tested soils was obtained. a good agreement was obtained between the observed and predicted data.