Mass transport subject to time-dependent flow with non-uniform sorption in porous media

TL;DR

This paper develops a general mathematical framework for modeling solute transport with trapping in porous media, incorporating non-uniform sorption rates, and validates it through numerical solutions and Monte Carlo simulations.

Contribution

It introduces a flexible model for solute transport that accounts for space-dependent sorption and trapping, extending previous models and providing numerical validation.

Findings

The model accurately predicts contaminant profiles.

Numerical solutions align well with Monte Carlo simulations.

Non-uniform sorption significantly affects transport dynamics.

Abstract

We address the description of solutes flow with trapping processes in porous media. Starting from a small-scale model for tracer particles trajectories, we derive the corresponding governing equations for the concentration of the mobile and immobile phases. We show that this formulation is fairly general and can easily take into account non-constant coefficients and in particular space-dependent sorption rates. The transport equations are solved numerically and a comparison with Monte Carlo particle-tracking simulations of spatial contaminant profiles and breakthrough curves is proposed, so to illustrate the obtained results.