Author(s)

J. Simunek & M. Th. van Genuchten

Abstract

In this paper we discuss a two-dimensional model, CHAIN 2D, for simu- lating the variably-saturated movement of water, heat, and multiple solutes involved in sequential first-order decay reactions. The model assumes that the solutes can reside in all three phases, i.e., liquid, solid, and gaseous. The solute transport equations consider convective-dispersive transport in the liquid phase, diffusion in the gaseous phase, nonlinear equilibrium or nonequilibrium sorption, linear equilibrium volatilization, zero-order production, and first-order degradation reactions which provide the necessary coupling between solutes involved in the sequential first-order decay reactions. Nonlinear sorption is described by a generalized formulation which can be simplified to either a Fr

Keywords