Mass Transfer Studies in Sorbing Porous Media I. Analytical Solutions

TLDR

The liquid phase in a porous medium is divided into mobile and immobile regions, with diffusional transfer proportional to concentration differences, and sorption in both regions is instantaneous with a linear isotherm. The study presents an analytical solution for chemical transport in sorbing porous media with lateral or intra‑aggregate diffusion. The model assumes instantaneous sorption with a linear isotherm and diffusion between mobile and immobile liquid phases. The analytical model explains the extensive tailing observed during flow through an unsaturated, aggregated sorbing medium and the early breakthrough of chemicals in the effluent.

Abstract

Abstract An analytical solution is presented for the movement of chemicals through a sorbing porous medium with lateral or intra‐aggregate diffusion. The liquid phase in the porous medium is divided into mobile and immobile regions. Diffusional transfer between the two liquid regions is assumed to be proportional to the concentration difference between the mobile and immobile liquids. Sorption processes in both the dynamic and stagnant regions of the medium are assumed to be instantaneous and the adsorption isotherm is assumed to be linear. The analytical model derived here describes the extensive tailing observed during flow through an unsaturated, aggregated sorbing medium and explains the often observed early breakthrough of chemicals in the effluent.