Effect of sorption hysteresis on the spatial distribution of contaminants in soils

A mathematical model of the combined transport of water and a dissolved contaminant in a peaty soil which takes hysteresis of the sorption and desorption processes into account is developed. The solvability of the initial and boundary value problems and the stability of the solutions are investigated. A series of problems characterizing the features of the contaminant distribution over peaty masses is solved numerically. A physical mechanism leading to the frequently observed effect of localization of the equilibrium sorbent distribution over the upper layer of soil is proposed. The effect of both the medium parameters and the regime of water and contaminant supply to the system is analyzed numerically.