This Phase II SBIR project involves the development, testing and modeling of a surfactant foam/bacterial delivery system for in situ remediation of dense non-aqueous phase liquid (DNAPL) contaminants. The Phase I study demonstrated the efficacy of combining a surfactant foam technology with bioaugmentation, to remediate trichloroethylene (TCE) contaminated aquifers. Results from this initial work suggested that foam facilitated transport of specialized microorganisms into subsurface aquifer sediments would result in the remediation of DNAPLs through mobilization and dispersion of the DNAPL and delivery of viable organisms for biodegradation. Objectives for the Phase II study include optimizing the foam and bacterial injection in order to maximize the scouring of the DNAPL and to enhance bacterial survival and TCE-degradation. In addition, this technology will be tested with: 1) numerous sediment types, 2) weathered sediment, and 3) other DNAPL contaminants. Data collected from the Phase II work will be used to develop a mathematical model to predict the fate of DNAPLs (extent of TCE mobilization and rate of TCE degradation) under field conditions. This model will be used to identify factors effecting the mobilization and degradation of TCE in the subsurface and will be used to design and predict field remediation efforts. Potential Commercial Applications of the Research Development of this technology will lead to a cost effective in situ bioaugmentation technology for treating even the most highly TCE-contaminated aquifers. Chlorinated solvent contamination of aquifers is one of the most common environmental liabilities at both government and industrial sites, therefore a process that can cost-effectively solve this problem will most likely be a commercial success.
