FIELD IMPLEMENTATION OF A WINSOR TYPE-I SURFACTANT ALCOHOL MIXTURE FOR IN-SITU SOLUBILIZATION OF A COMPLEX LNAPL AS A SINGLE-PHASE MICROEMULSION/

A Winsor Type I surfactant/alcohol mixture was used as an in situ flus hing agent to solubilize a multicomponent nonaqueous phase liquid (NAP L) as a single-phase microemulsion (SPME) in a hydraulically isolated test cell at Hill Air Force Base (AFB), Utah. The surfactant (polyoxye thylene(10) oleyl ether) and alcohol (l-pentanol)together comprised 5. 5 wt % of the flushing solution. The NAPL was extremely complex, conta ining more than 200 constituents and a 'pitch' fraction that was not s olvent-extractable. The NAPL removal effectiveness of the SPME flood w as evaluated using information from soil cores, partitioning tracer te sts, and NAPL constituent breakthrough curves (BTCs) measured at three extraction wells. Soil core data indicated that approximately 90-95% of the most prevalent NAPL constituents were removed from the cell by the SPME flood. A comparison of pre- and postflushing partitioning tra cer data indicated that about 72% of the measured NAPL volume was remo ved by the SPME flood. Integration of NAPL constituent BTCs indicated 55-75% removal of the target NAPL constituents when partitioning trace r data were used to estimate the initial amount of NAPL present and 60 -175% removal of two target constituents when soil core data were used to estimate the amount of NAPL initially present. These results indic ate that the SPME flood effectively removed the NAPL constituents of c oncern, but an insoluble anthropogenic residue was left behind.