Generalized semi-analytical solution for coupled multispecies advection-dispersion equations in multilayer porous media

Multispecies contaminant transport in the Earth's subsurface is commonly modelled using advection-dispersion equations coupled via first-order reactions. Analytical and semi-analytical solutions for such problems are highly sought after but currently limited to either one species, homogeneous media, certain reaction networks, specific boundary conditions or a combination thereof. In this paper, we develop solution case of heterogeneous layered medium general network. Our approach combines transformation method decouple multispecies with recently developed single-species advection-dispersion-reaction equation media. The generalized valid arbitrary numbers species layers, Robin-type at inlet outlet accommodates both distinct retardation factors across layers species. Four test cases presented demonstrate reported results agreement previously published numerical obtained finite volume discretisation. MATLAB code implementing made available.