Peel, T, M. Castellanos, M.L. McMaster, J. Adkisson, S. Dworatzek, "Bioremediation of TCE Source Area at the Mobile Launch Platform Rehabilitation Sites and Vehicle Assembly Building", poster presentation, presented at the Battelle Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 2002.
Microcosm tests were conducted to evaluate the potential to biodegrade trichloroethene (TCE) in groundwater at Kennedy Space Center (KSC), Florida. Microcosm treatments were constructed to: (i) evaluate if indigenous microorganisms at the site could be stimulated with electron donors to completely dechlorinate TCE; and (ii) assess the potential for bioaugmentation with KB-1, a natural, non-pathogenic, dehalorespiring microbial culture that improves the rate and extent of dechlorination. The microcosm treatments amended with electron donors indicated that reducing conditions were present at incubation day 36. Although natural microbial populations had developed, TCE was only slowly degrading to cis-1,2-dichloroethene (cis-1,2-DCE) after 126 days of incubation. These results tend to indicate that the natural population of dehalorespiring bacteria is low and that the electron donor enhancement alone did not sufficiently stimulate growth. At day 36, microcosm treatments amended with electron donors were bioaugmented with the KB-1 culture. Complete TCE dechlorination via cis-1,2-DCE and vinyl chloride (VC) to ethene was observed in the bioaugmented treatments. Microcosm results indicate that the average time required to degrade TCE and cis-1,2-DCE by one half (half-life) was 4 and 15 days, respectively. The results, after 205 days of incubation, indicated that bioaugmentation with KB-1 can greatly improve the rate and extent of TCE dechlorination. Complete biodegradation of TCE and its degradation products to ethene was observed in the microcosms bioaugmented with KB-1.