| Abstract: | A promising new technology for the detection of dense nonaqueous phase liquids, or DNAPLs, is cosolvent injection/extraction. Cosolvents, such as alcohols, are injected into the subsurface and interact with DNAPLs to increase their aqueous solubility, which increases recovery of the chemicals. A laboratory assessment was performed to determine if incorporating this technology with cone penetrometers could provide a useful sampling tool for DNAPL detection. A cone penetrometer was modeled in the laboratory by injecting and extracting small quantities of ethanol and propylene glycol at low concentrations into a homogeneous sand reactor contaminated with a residual saturation of tetrachloroethene (PCE). Experimental test results show that this technology is extremely sensitive to the vertical placement of the sampler, but is capable of enhancing PCE solubility while recovering most of the alcohol injected. Field testing of this technology will provide the next step in determining the feasibility of this technology for DNAPL detection. |
