Theses and Dissertations at Montana State University (MSU)
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Item Bio-trapping ureolytic bacteria on sand to improve the efficiency of biocementation(Montana State University - Bozeman, College of Engineering, 2023) Ugur, Gizem Elif; Chairperson, Graduate Committee: Chelsea M. Heveran; Adrienne J. Phillips (co-chair); This is a manuscript style paper that includes co-authored chapters.Microbially induced calcium carbonate precipitation (MICP) has emerged as a novel biocementation technique for its potential solution to sustainable construction. Although current MICP approaches have made significant progress, achieving spatial control over biomineralization is challenging due to its complexity, which is affected by many factors, such as microorganisms, reaction kinetics, and environmental factors. Spatially controlling biomineralization for building or targeted repair of materials can significantly improve efficiency and sustainability while achieving desired outcomes. The purpose of this thesis was to assess whether biomineralization can be enhanced through surface pre-treatment of sand using amino silanes, such as 3-aminopropyl-methyl-diethoxysilane (APMDES), which is one form of spatial control of biomineralization through prescribing the location of the microbes. Moreover, a preliminary study was conducted to assess whether biomineralized sand, with and without the APMDES treatment, can be recycled and reused for biomineralization of subsequent generations. The impact of APMDES treatment on bacterial adhesion on sand, growth, and urease activity was analyzed. Biocementation efficiency was evaluated by comparing compressive strength and calcium gain of APMDES-treated sand with untreated sand. APMDES treatment promotes abundant and immediate trapping of bacteria on sand surfaces through increased electrostatic interaction that attracts negatively charged walls of bacteria to positively charged amine groups. While APMDES treatment compromises microbial viability, it preserves the urease enzyme for catalyzing urea hydrolysis. APMDES-treated sand achieved comparable strength with fewer bacterial injections compared to untreated sand. APMDES-treated sand biocemented using three injections of bacteria and cementation media gained the same strength as seven injections. Biomineral gain of APMDES-treated sand was similar compared to untreated sand, which shows calcium accrual in the structure may be influenced by additional factors, such as the distribution of calcite, differences in the calcite precipitation patterns, and morphology. Overall, incorporating APMDES treatment can potentially improve the efficiency and sustainability of MICP by spatially controlling biomineralization.Item Kinetics of thermally inactivated ureases and management of sand production through ureolysis-induced mineral precipitation(Montana State University - Bozeman, College of Engineering, 2018) Morasko, Vincent John; Chairperson, Graduate Committee: Robin Gerlach; Adrienne Phillips (co-chair)Biocement has the potential to seal subsurface hydraulic fractures, manipulate subsurface flow paths to enhance oil recovery, treat fractured cement, stabilize soil structures and minimize dust dispersal. Biocement can be formed using the urease enzyme from various sources (bacteria, plant, or fungi) to break down urea into carbonate, combining with calcium for use in engineering applications such as biocement production. Higher temperatures, pressures, and extreme pH conditions may be encountered as these engineering applications expand deeper into the subsurface. Temperatures beyond 1000 meters can exceed 80°C, potentially rapidly inactivating the enzyme. The first part of this study focused on monitoring urea hydrolysis catalyzed by jack bean urease at temperatures ranging from 20-80°C. An increasing rate of urease inactivation was observed with increasing temperatures and first-order models described the kinetics of urea hydrolysis and enzyme inactivation properly. The second part of this study focused on developing a technology to mitigate sand transport in oil and gas wells. This study addressed a method to cement sand in the subsurface so that it is not returned when oil or gas is extracted. As the sand leaves the formation, it can cause damage in the subsurface, leading to economic concerns, as well as reducing the lifespan of pumps, piping and other components on the well pad. A reactor system was developed to mimic a subsurface oil well that produces sand. Biocement production was promoted within the reactor, utilizing common sources of urease (Sporosarcina pasteurii and Canavalia ensiformis or jack bean meal). The resultant calcium carbonate/sand mass was subjected to elevated flowrates, simulating field conditions where sand is potentially fluidized and potentially transported into the wellbore. It was shown that biocement can reduce sand transport while allowing for higher flow rates than conditions without biocement. The findings from this study broaden the potential application range of biocementation technologies into higher temperature environments. Applying biocement specifically to sand mitigation may have significant environmental, economic, and safety implications within the natural resource industry.Item Sand dunes of the Darhat Valley Mongolia : understanding their origins, dynamics, and impacts on soils and vegetation(Montana State University - Bozeman, College of Agriculture, 2001) O'Connell, Patrick Harold