Degradable Solute Transport in Porous Media with Variable Hydrodynamic Dispersion

Degradable solute transport in porous media significantly influences various ecological, geological, and industrial processes. In this paper mathematical model for solute transport in porous media with varying hydrodynamic dispersion is examined, integrating balance and kinetic equations alongside initial and boundary conditions. The model is enhanced by include variable hydrodynamic dispersion. Numerical approaches are utilized to address the problem, and a solution algorithm founded on the finite difference method is introduced. Computer simulations are conducted to examine the impact of different model parameters on solute transport, and the findings are evaluated. Numerical tests were performed for constant dispersion and three representative spatially variable forms—exponential, linear, and parabolic for same other model parameters. Simulations show that neglecting diffusion/dispersion significantly delays the transport of material and underestimates both aqueous concentrations and adsorbed reserves. Introducing even simple dispersion accelerates transport across the domain and increases adsorption in both zones. Using differnt expressions for dispersion, in turn, leads to different results.