Three-Dimensional Analysis of Contaminant Migration through Saturated Homogeneous Soil Media Using FDM

Finite-difference method (FDM) is applied herein to solve the three-dimensional (3D) contaminant transport model to predict pollutant migration through clay liner or clay deposit in waste landfill. The seven pollutant species typically found in municipal and industrial wastes are considered in this study. Physical processes such as advection, dispersion, diffusion, geochemical reactions, and first-order decay are considered in the governing equation. The computer program CONTAMINATE-3D was developed to solve the 3D analysis of the contaminant migration model. A comparative study between one-dimensional and 3D analysis is presented in this paper based on the proposed methodology considering unidirectional flow and dispersion in three directions. Based on the present 3D analysis, design charts for liners and concentration profiles of contaminant species passing through liner media were developed to facilitate the designers' work. Contaminant plumes were also developed within the aquifer considering unidirectional and uniform groundwater velocity to illustrate the effect of the vertical-plane patch source of constant concentration on the neighboring areas of the landfill site using the proposed solution technique of 3D contaminant transport model.