Comparison of Contaminant Partitioning Short-Chain Fatty Acids versus Lactate as Electron Donor Sources to Support Dechlorinating Bacteria.
Bonilla, Eimy X.
- Chlorinated solvents, such as trichloroethene (TCE) and tetrachloroethene (PCE), have been used as degreasers in the manufacturing of metal pieces and dry cleaners for decades. TCE and PCE have been found to increase the risk for human health impacts at a concentration of 5 micrograms per liter when ingested in water and have been classified as potential or actual human carcinogens by the USEPA. ... read moreBioremediation involves natural subsurface microbes and has the potential of reducing the toxicity of chlorinated solvents by reductive dechlorination, which breaks down the chlorinated solvents to harmless ethene.Previous studies performed in abiotic sand-packed columns have shown that certain short-chain fatty acids persist much longer in contaminant zones than soluble that does not readily mix with contaminant. These results demonstrated that these fatty acids partitioned in and out of the contaminant and could potentially provide a sustained source of fermentable electron donor (food source) to support microbial reductive dechlorination. Biotic batch reactors were used to test the effectiveness of potential PEDs compared to lactate, a common electron donor. The results for this study show that short fatty acids, n-butyl acetate and isopropryl propionate are potential partitioning electron donors that support microbial reductive dechlorination. The potential PED that did not support the microbial community was 2-ethyl-1-hexanol.read less