Available at: https://digitalcommons.calpoly.edu/theses/2672
Date of Award
12-2022
Degree Name
MS in Civil and Environmental Engineering
Department/Program
Civil and Environmental Engineering
College
College of Engineering
Advisor
Nirupam Pal
Advisor Department
Civil and Environmental Engineering
Advisor College
College of Engineering
Abstract
Aqua, a commercial product manufactured by BiOWiSH® Technologies, was utilized in this research to study its effectiveness to biodegrade methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Microcosms containing varying concentrations of MTBE and TBA as well as a growth media and mineral salt solution were examined. Analytical instrumentation used in this study included the use of a gas chromatograph-mass spectrometer (GC/MS) to determine concentrations of MTBE and TBA and a spectrophotometer to extrapolate approximate active biomass concentrations in each experiment. Four different environmental conditions were tested for both MTBE and TBA. The environmental conditions tested for each contaminant included: biodegradation under aerobic conditions, biodegradation under anaerobic conditions, biodegradation under denitrifying conditions, and biodegradation under aerobic conditions with glucose present.
This study concluded that there is potential for degradation of MTBE and TBA using Aqua under the conditions tested. Maximum MTBE biodegradation was observed under aerobic conditions which yielded a first order rate constant of 0.019/hour and a 99.8 percent decrease in MTBE over 14 days. Maximum TBA biodegradation was observed under aerobic conditions with glucose present which yielded a first rate order constant of 0.009/hour and a 95.03 percent decrease in TBA concentrations over 14 days. It is presumed that under both conditions a monooxygenase enzymatic reaction involving Cytochrome P-450 aids in breaking down both MTBE and TBA. However, the results presented are indicative of biodegradation under lab conditions with little to no interference. Further research is needed to determine the effectiveness of Aqua utilizing groundwater or soil samples from MTBE or TBA contaminated sites in order to truly analyze Aqua’s potential to be used as a bioaugmentation product in real world applications.