Numerical Methods for Nonequilibrium Solute Transport with First-Order Decay and Zero-Order Production

Abstract. Solute transport in the subsurface is often considered to be a nonequilibrium process. Nonequilibrium during transport of solutes in porous medium has been categorized as either transport-related or sorption-related. For steady state flow in a homogeneous soil and assuming a linear sorption process, we will consider advection-diffusion adsorption equations. In this paper, numerical methods are considered for the mathematical model for steady state flow in a homogeneous soil with a linear sorption process. The modified upwind finite difference method is adopted to approximate the concentration in mobile regions and immobile regions. Optimal order l2error estimate is derived. Numerical results are supplied to justify the theoretical work.