Pore-scale modelling of mass transfer from non-aqueous phase liquids

We use a stagnant-layer diffusion concept for mass transfer across individual fluid-fluid interfaces at the pore scale, coupled to a capillary displacement model in a pore network. Mass fluxes are computed across each interface, then transport equations are solved in the pore network to determine concentrations in the aqueous-phase. The model is used to predict dissolution fronts developed by flushing water through a porous medium initially at residual NAPL saturation.