Biologically enhanced mass transfer of tetrachloroethene from DNAPL in source zones: experimental evaluation and influence of pool morphology.

High-saturation pools of dense nonaqueous phase liquid (DNAPL) are long-term sources of groundwater contamination at many hazardous-waste sites. DNAPL pools consist of a high saturation zone with slow dissolution overlaid by a transition zone with lower saturations and more rapid dissolution. Effects of biological activity on pool dissolution must be understood to evaluate and implement bioremediation strategies.