Simulation of solute transport in porous media using a one-dimensional nonlinear sorption transport model controlled by equilibrium

Studies on the flow and transport of contaminants in the subsurface environment rely on the knowledge of numerous functional parameters of the subsurface. One of these parameters is the retardation factor generated by the non-linear sorption isotherm, which presents significant ambiguities in its estimation in homogeneous media, challenging accurate predictions of contaminant transport and retention. This study uses a mathematical model to simulate the transport of contaminants in saturated porous media under Freundlich and Langmuir isotherm models. This study evaluates the impact of non-linear sorption on contaminant distribution and addresses ambiguities in parameter estimation. Using two sorption isotherm models dependent on porosity ( Ɵ ) in the domain, the analysis of the results shows that for θ values < 0.15, significant solute mass retention is observed with the Freundlich model, while concentration profiles between both models are similar for θ ≥ 0.15. These findings emphasize the importance of considering porosity and appropriate isotherm models to improve the accuracy of predictive modeling for contaminant transport in subsurface environments.