ANALYSIS OF TWO-DIMENSIONAL CROSS-FLOW OF REACTIVE CONTAMINANT

Abstract

The advection-dispersion equation is commonly employed in studying solute migration in a flow. This study presents semi-analytical solution of two-dimensional contaminant flow models incorporating the cross-flow dispersion parameter and a decay term for evaluating groundwater contamination in a homogeneous finite medium. In deriving the model equations, it was assumed that there was a constant point-source concentration at the origin. Two models were considered: case 1 with Neumann boundary conditions and case 2 with associated Dirichlet boundary conditions. The cross-flow dispersion, horizontal dispersion, vertical dispersion, velocities and decay terms are time-dependent. The model equations were transformed and solved by combined parameter expanding method, Eigen-functions expansion method and direct integration method. The results which investigate the effect of change in the parameters on the concentration were discussed and represented graphically for suitable initial values of

the parameters DL0  1.0, DT 0  1.5, DLT 0  4.0, q  3.0, u0  0.1, v0  0.1 and   0.1, The study revealed that as the decay parameter increases, the contaminant

concentration decreases with time in the two cases considered, while in case 2, the contaminant concentration declines with both time and distances as the values of the parameters listed above increase.