Propane-induced biodegradation of vapor phase trichloroethylene
- John Carollo Engineers, College Station, TX (United States)
- Texas A and M Univ., College Station, TX (United States). Dept. of Civil Engineering
Microbial degradation of trichloroethylene (TCE) has been demonstrated under aerobic conditions with propane. The primary objective of this research was to evaluate the feasibility of introducing a vapor phase form of TCE in the presence of propane to batch bioreactors containing a liquid phase suspension of Mycobacterium vaccae JOB5 to accomplish degradation. The reactor system consisted of three phases: a vapor phase introducing air, propane, and a solid phase in the form of the microorganisms. Long-term and initial rate experiments were conducted on three culture sets to evaluate microbial response. In two long-term tests fed propane and approximately 0.1 mg/L and 1 mg/L of TCE, respectively, propane utilization was more efficient at the high TCE concentration because the propane degradation rate was approximately the same for both tests. In addition, TCE utilization decreased after complete propane consumption. Initial rate tests on culture sets fed propane only revealed that cells with a history of exposure to a high concentration of TCE had the highest specific growth rate, but the lowest half-saturation constant. Tests fed variable TCE concentration (0.031 to 5.378 mg/L in the liquid phase) with no propane showed TCE depletion but no biomass growth. The tests revealed that the TCE removal increased as the TCE concentration increased, indicating a greater removal efficiency at the higher concentrations. Tests with a constant initial propane concentration and variable liquid phase TCE concentration revealed that specific propane utilization was essentially the same.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 64507
- Journal Information:
- Biotechnology and Bioengineering, Journal Name: Biotechnology and Bioengineering Journal Issue: 4 Vol. 46; ISSN 0006-3592; ISSN BIBIAU
- Country of Publication:
- United States
- Language:
- English
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