Coupling Physical, Chemical, or Biological Methods for Innovative Groundwater Remediation Coupled Polymer Floods and Bio-Chemical Remediation Techniques for Enhanced Groundwater Treatment

Many groundwater remediation techniques are designed to remove or destroy contaminants in situ , but these goals can be accomplished only by successful delivery of the remediation agent to areas of contamination. Remediation is often hindered because contaminants reside in interfingered layers or zones of low permeability. Aquifer heterogeneities can therefore inhibit the effectiveness of injection-based remediation schemes due to preferential-flow bypassing of lower-permeability zones. Failure to treat contaminants trapped in these areas can result in rebounding groundwater contaminant concentrations, as these compounds later diffuse outward into previously treated groundwater regions. Because the effectiveness of many treatment techniques has already been demonstrated in laboratory settings, the immediate focus of our research is not to develop new bio-chemical remediation techniques, but rather to improve the delivery of existing treatment agents. Coupling polymer flood technology (used previously in the oil industry for enhanced recovery efforts) with previously field-tested remediation schemes has the potential to increase groundwater clean-up effectiveness, as a result of more directed agent delivery. The difference in viscosity between a co-injected polymer flood and ambient groundwater creates a more stable injection front, which induces flow through zones of differing permeability. However, the polymer solutions and the remediation agent must be chemically and/or biologically compatible to achieve better treatment results. This presentation demonstrates the effectiveness of polymer-assisted delivery of remedial agents, and investigates the compatibility between polymers and two common remediation methods: in situ chemical oxidation (ISCO) and bioremediation.