Effect of anti-Langmuir adsorption on spreading in porous media

Abstract

When given solutes are transported in porous media flows, various propagation regimes can be observed depending on the adsorption isotherms. We perform numerical simulations to investigate the influence of an anti-Langmuir adsorption isotherm (overloading isotherm) on the spreading of a miscible solute-rich slice in a porous medium. Selecting the characteristic scaling of the solute concentration appropriately, the dynamics of the anti-Langmuir adsorbed solute is studied in the pure diffusion-convection conditions as well as under the influence of viscous fingering. The similarities and differences between the spreading of Langmuir and anti-Langmuir adsorbed miscible slices are analysed as a function of the parameters of the problem.