This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
Groundwater contamination is of environmental and human health concern. Bioremediation is a nature-based method for contaminant treatment. Bioremediation, which relies on the ability of microorganisms to destroy or transform contaminants, must be reliable and cost-competitive in comparison to more traditional treatment methods. Two hurdles must be overcome…
Groundwater contamination is of environmental and human health concern. Bioremediation is a nature-based method for contaminant treatment. Bioremediation, which relies on the ability of microorganisms to destroy or transform contaminants, must be reliable and cost-competitive in comparison to more traditional treatment methods. Two hurdles must be overcome to enhance bioremediation’s effectiveness and competitiveness: i) being able to degrade recalcitrant compounds, and ii) being able to control the growth rate and location of microorganisms involved in bioremediation in the subsurface. My dissertation adds foundational knowledge and engineering application on how to biodegrade recalcitrant emerging and legacy halogenated compounds. Generating biotransformation knowledge on the recalcitrant emerging contaminants called per- and polyfluoroalkyl substances (PFAS) may lead to solutions for protecting both people and the planet. In my dissertation, I analyzed PFAS biotransformation and microbial defluorination literature via meta-analytical and bibliometric methods to identify unexplored topics and experimental conditions. The metanalytical work identified trends in PFAS microbial biotransformation science to inform future experimental design.
The second hurdle which must be overcome is being able to control bacterial growth in the subsurface. During bioremediation implementation microbial overgrowth may clog injection wells and the subsurface, leading to reduced porosity and treatment efficacy. Contaminant treatment schemes based on aerobic cometabolism frequently exhibit overgrowth at subsurface injection points for O2 (the electron acceptor) and a labile hydrocarbon (e.g., propane). My dissertation work experimentally evaluated acetylene as a microbial inhibitor for use in controlling microbial overgrowth during trichloroethene (TCE) aerobic cometabolism. I demonstrated that acetylene reduces the likelihood of microbial overgrowth of TCE-degrading microorganisms in soil-free microcosms and aquifer soil columns while retaining TCE degradation capacity. Cumulatively, my dissertation provides foundational knowledge for academics and bioremediation practitioners to develop robust and reliable bioremediation technologies.
