3-DIMENSIONAL ANALYTICAL MODELS OF CONTAMINANT TRANSPORT FROM NONAQUEOUS PHASE LIQUID POOL DISSOLUTION IN SATURATED SUBSURFACE FORMATIONS

Closed form analytical solutions are derived for three-dimensional transient contaminant transport resulting from dissolution of single-component nonaqueous phase liquid pools in saturated porous media. The solutions are suitable for homogeneous porous media with unidirectional interstitial velocity. The dissolved solute may undergo first-order decay or may sorb under local equilibrium conditions. The solutions are obtained for rectangular and elliptic as well as circular source geometries, assuming that the dissolution process is mass transfer limited, by applying Laplace and Fourier transforms. Although the solutions contain integral expressions, these integrals are easily evaluated numerically. These solutions are useful for verifying the accuracy of numerical solutions to more comprehensive models and for design and interpretation of experiments in laboratory-packed beds and possibly some field studies. The results of several simulations indicate that for short downstream distances, predictions of contaminant concentrations are sensitive to the source structure and orientation with respect to the direction of interstitial flow.