Evaluation of remediation performance and cost for field-scale single-phase microemulsion (SPME) flushing

Pump-and-treat strategies employed to contain contaminant plumes have been demonstrated to be inefficient, and often ineffective, for remediation of aquifers contaminated by nonaqueous phase liquids (NAPLs). This has prompted the development of alternative technologies to provide enhanced remediation of NAPL source zones. The results reported here are from a solubilization study wherein the objective was to achieve high NAPL remediation efficiencies using a low concentration of chemical additives in the flushing solution. A surfactant/alcohol mixture was used to generate a Winsor Type I system, where the NAPL was solubilized and transported as a single-phase microemulsion (SPME). For the SPME process, only 5.5 wt% of the flushing solution comprised chemical additives. The costs associated with this project are discussed and approaches aimed at reducing costs are suggested.