Experimental investigation of contaminant transport through saturated porous media under groundwater flow

Contaminant transport in groundwater has been growing concern during last decades, since pollution can leach through the soil and reach the groundwater. The present research has been investigated solute migration through saturated porous media by the physical modeling laboratory, result in practical graph, determining the general pattern of contaminant plume in both homogeneous and heterogeneous layers. Three types of sand are selected for experimental model, which include both coarse and fine aggregate. The results indicate that in the coarse aggregate medium, the movement of pollution is 10 times faster than the fine aggregate containing 10% silt and 1.5 times faster than the fine aggregate sand without silt. The ratio of the length to width of the contaminated area in the coarse-grained soil in comparison to the fine-grained soil containing silt, and without silt increases 110 % and 40% respectively. In the heterogeneous fine- coarse model, Darcy velocity magnitude in coarse aggregate medium is much greater than fine aggregate result in more advection. In this case, because of the significant difference in velocity values in the two layers, the pollutant is rapidly transferred to the downstream after reaching the border of the two areas. Also, in the frontier of the coarse- fine medium, pollution is dispersed more for the fine aggregate medium acts as though it were the wall.