One-dimensional migration of an active substance involving subsurface advection, diffusion and sorption phenomena

Author: M. Sławomirski

In this paper one-dimensional migration ofthe chemically active substance in the porous rock mass has been considered.

It has been assumed that the active substance dissolved in water flowing through rocks is subjected simultaneously to the advection, diffusion, dispersion, sorption, ion exchange, and chemical disintegration processes.

For the description of the problem the differential equations of balance and kinetics have been applied. The considerations are restricted to the initial phase of the migration process.

Consequently, it has been assumed that at the initial time t = O the concentration of dissolved active substance C and the concentration of active substance sorbed in the rock are equal to zero. Moreover, the general non-linear kinetics equation may then be approximated by means of the linear relation.

The differential equation describing the migration process has been solved applying the Carson-Laplace integral transform method.

The solution for the case when the diffusion-dispersion process may be neglected has been compared to the solution for a the situation in which the diffusion and dispersion influence the pattern of the migration phenomenon.