Effect of the durability of GCLs on Contaminants transfer through a composite liner exhibiting a hole in the geomembrane: A numerical approach

Abstract

This study performs numerical simulations of flow rate and organic contaminant migration through a geosynthetic composite lining system (geomembrane GMB-geosynthetic clay liner GCL) using the GeoStudio program (Ctran/W in conjunction with Seep /W). The GMB is considered defective with a circular hole to account for the coupled phenomena of advection and diffusion. GCLs are considered virgin and suggested for cation exchange and thermal gradient to verify and check the effect of the internal modification and alteration of the GCL by its environment on contaminant transfer. The results are compared with contaminant transport through composite liners with virgin GCL to investigate and study the resistance durability of GCLs to face contaminant transfer transport. After the validation of the proposed model, there was good agreement between the simulated and experimental flow. The result of this study confirms that indeed the typically published diffusion coefficient values for both virgin and aged GCL used in the present study provide good predictions of contaminant migration and effluent concentration over time across the GMB-GCL composite liners