Appraisal of Ogata Solution for Solute Transport

Abstract

The advection-dispersion equation is often used to describe subsurface contaminant solute transport in a homogeneous, isotropic, and saturated geologic porous medium. An analytical solution to the equation has been developed by Ogata assuming the domain of space is extended from zero to infinity. However, the length of the column of geologic porous medium used in laboratory experimental studies is always finite. Criteria for applicability of the solution in analyzing experimental data obtained from column experiments are established in this paper. The velocity of the 50% concentration point of the concentration profile is often erroneously taken as the retarded advective velocity of the contaminant solute to determine the retardation factor and distribution coefficient of the contaminant between the solid and liquid phases. The error is carefully investigated for different boundary conditions of the experiments and necessary corrections are recommended. Detailed procedures for different applications of the developed correction charts are also presented in this paper.