Chapter 7
It is clear that surfactant and cosolvent flushing is an emerging technology that will require further development before seeing routine use at hazardous waste sites. Research directed at the evaluation and improvement of surfactant and cosolvent flushing for subsurface remediation is currently active and ongoing in many institutions worldwide. The next few years will likely bring with them many advancements and innovations. Listed below are several areas of investigation that will require attention:
• Improved methods for aboveground produced fluids treatment
• Rate-limited mass transfer between NAPL and injected chemical agents
• Diffusion from low permeability media
• Improved deliverability in heterogeneous porous media and fractured rock
• Site characterization to delineate NAPL source zones
• Control of vertical DNAPL mobilization
• Degradation of surfactants and cosolvents, including fate of residual chemicals
• Aquifer reconditioning
• Evaluation of the benefits in terms of risk reduction and/or other site care requirements of surfactant/cosolvent flushing.