Dissolution of a multicomponent DNAPL pool in an experimental aquifer

This paper presents the results from a well-defined, circular-shaped, multicomponent dense nonaqueous phase liquid (DNAPL) pool dissolution experiment conducted in a three-dimensional, bench scale model aquifer. The multicomponent pool is a mixture of tetrachloroethylene (PCE) and 1,1,2-trichloroethane (1,1,2-TCA); PCE was the major component and 1,1,2-TCA was the minor component. Downgradient plume concentrations were measured at five specific locations over time until the majority of the 1,1,2-TCA was depleted from the DNAPL pool source. The experimental results suggest distinct spatial-temporal plume patterns for minor DNAPL components versus major DNAPL components. The downgradient concentration varied over time for 1, 1,2-TCA while a stable plume developed for PCE. A semi-analytical solution for contaminant transport resulting from dissolution of multicomponent nonaqueous phase liquid pools successfully simulated the plume structure and dynamics for both the major and minor DNAPL components. (c) 2005 Elsevier B.V. All rights reserved.