Contaminant Transport in Nonisothermal Fractured Porous Media

Abstract

Alternative formulations of the analytical modeling for contaminant transport in nonisothermal fractured porous media are presented. Transient and steady heat flows are coupled with solute transport, either implicitly as natural convection incorporating the effect of thermal flux on the variation of concentration gradients, or explicitly as a “Soret effect,” where the divergence of the thermal flux acts as an additional source term affecting the change of solute concentration. The effect of solid deformation due to temperature changes and subsequent impact on the variation of solute concentrations are identified. The proposition of using function transformation within Laplace space may be of significance for numerical implementation in solving advection-dispersion equations. Two different dual-porosity conceptualizations of fractured porous media are proposed based on alternative assumptions of matrix flow. The concept of “matrix replenishment” in relation to the traditional “matrix diffusion” is presented, which may have practical significance in the evaluation of contaminant transport in fractured porous media. The solutions are applicable for modeling the process using thermal sweeping to remediate contaminated areas.