Multiple Co-Substrates for In Situ Biostimulation of TCE Degradation

This Phase I SBIR project involves the use of multiple co-substrates to stimulate in situ bioremediation of chlorinated solvent-contaminated aquifers. Several groups of naturally-occurring bacteria are capable of co-metabolically degrading chlorinated solvents while growing on different co-substrates such as methane, propane and butane. During this project we will perform laboratory studies to address the use of multiple co-substrates to simultaneously stimulate multiple groups of chlorinated solvent-degrading microorganisms. Initial experiments will be performed in laboratory aquifer microcosms that will allow careful measurements of chlorinated solvent degradation and the calculation of a mass balance of the amount of solvent and growth substrate added to the microcosms and degraded by the natural microbial propulations. Trichloroethylene (TCE) will serve as a test chlorinated solent, and its degradation kinetics will be fitted to currently-available co-metabolic degradation models. Growth of different microbial populations in response to co-substrate feeding will be measured to address the feasibility of stimulating multiple degradative populations. Experiments will be performed to select the best combination of co-substrates and to optimize co-substrate feeding regimes to maximize chlorinated solvent degradation, and develop an efficient and cost-effective in situ bioremediation technology. The technology will be suitable for use at many government and private sites containing chlorinated solvent-contaminated aquifers.