Modelowanie numeryczne transportu substancji aktywnych z uwzględnieniem sorpcji i reakcji chemicznych w oparciu o równania różniczkowe adwekcji i kinetyki procesów

The problem of transfer of active substances dissolved from underground depository of industrial waste materials by subsurface water has been considered. It is assumed that the advection of dissolved active substance is modified by diffusion, sorption, and chemical reactions occurring in the solution. The problem has been described by the system of non-linear partial differential equations. The system of equations has been solved applying the finite difference technique. The original semi-implicite finite difference algorithm has been implemented within the computer program for the Digital AlphaStation RISC type computer. The solution of the problem is represented by the single concentration wave which moves from the boundary of depository with the advection velocity (cf. Fig. 1). The magnitude of the concentration wave is progressively decreased in distance from the boundary of the depository owing to sorption, ion exchange, and chemical disintegration of the active substance. The sharp edge of the wave is gradually `flattened’ as the result of diffusion and dispersion effects.