Density-enhanced remediation of non-aqueous phase liquid contamination of subsurface environments

摘要

A method for remedying contamination of a subsurface environment by a non-aqueous phase liquid that is denser than water (DNAPL). The subsurface environment has a resident aqueous phase and a DNAPL phase. A dense aqueous solution that has a density greater than a density of the DNAPL phase is introduced to the subsurface environment. The dense aqueous solution displaces the resident aqueous phase and causes the DNAPL phase to rise above the greater density aqueous solution. The DNAPL phase is then recovered, which substantially remedies the contamination of the subsurface environment. An alternative method provides for introducing a dense solution layer that has a density greater than the density of the DNAPL phase beneath the subsurface region contaminated with the DNAPL phase. Next, the water table is lowered so as to create an unsaturated porous medium above the dense solution layer and to downwardly mobilize the DNAPL phase to the top of the dense solution layer. The DNAPL phase is then collected from the top of the dense solution layer.