Patent ID: 6274048
Filing Date: 2001-08-14
Classification: B09C

Abstract:
Procedure for treating contaminated groundwater in its native aquifer, wherein:the material of the aquifer is porous, and the aquifer is permeable to the through-flow of groundwater, at least laterally, to the extent that liquid readily moves and spreads laterally through the pore spaces in the aquifer;the aquifer has a hydraulic conductivity greater than 10.sup.-6 cm/sec;the aquifer includes a bed-layer, which has a hydraulic conductivity lower than 10.sup.-7 cm/sec;the contaminant is a dense non-aqueous-phase liquid, which has settled on the bed-layer, and is in the form of a liquid lens, of comparatively small vertical height and large lateral extent;the procedure includes introducing treatment liquid into the aquifer, and of injecting the treatment-liquid in the form of a coherent layer of the treatment-liquid, termed a treatment-lens;the treatment-liquid is concentrated enough to cause chemical breakdown of the DNAPL contaminants in the groundwater;the treatment-liquid is substantially more dense than the groundwater, whereby, upon injection of the treatment liquid into the aquifer, the treatment liquid starts to sink down;and the procedure includes the steps of so placing the treatment-lens of the treatment-liquid in the aquifer as to overlie a portion of the lens of DNAPL, just above the lens, whereby the dense treatment-liquid, in sinking, spreads out progressively laterally for a large distance, over the bed-layer and over the lens of DNAPL.