Unsteady state contaminants transport in sandy mediums using CFD model

Abstract

This study was conducted to provide a CFD simulation model to simulate the transfer of pollutants through sandy soils. A physical model and simulation model were designed and implemented with the help of CFD programs using COMSOL 5.4 software to study the process of transporting pollutants within the porous medium. To study the pollutant transmission in the porous media, a sand size of less than 0.36 mm diameters was used as porous media. For an analysis of the problem, several groups of factors were considered and assumed. The first group concerned with the physical properties of the media likes coefficient of adoption Kd. The second group represented the hydraulic factor of flow likes velocity. The results of the physical and CFD models showed there is a clear effect of soil physical properties due to the coefficient of adsorption Kd action. The velocity has a significant effect on the concentrations of pollutants and the time of transmission where the lower velocities produce lower concentrations and delayed transport of pollutants in the soil. The CFD simulated model showed that the change in the Kd-value has a significant impact on the results. The study also showed a good agreement between the results of the laboratory work provided by the physical model and that of the CFD model depending on several statistical indexes. This indicates that the CFD models could be considered as an efficient tool to simulate the complex problems of contaminates transport through a porous medium.