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Item Material properties of ureolytically induced calcium carbonate adhesives(Montana State University - Bozeman, College of Engineering, 2023) Anjum, Sobia; Chairperson, Graduate Committee: Robin Gerlach; This is a manuscript style paper that includes co-authored chapters.Polymers used in adhesive applications are often petrochemical-based and release volatile organic compounds (VOCs) during application. These VOCs can accumulate indoors to the detriment of human health. Biopolymers potentially offer a non-toxic and sustainable alternative to synthetic polymers but generally have limited physical stability and low mechanical performance. One of the methods of improving the stability and adhesive performance of biopolymers is the addition of a mineral phase to reinforce biopolymer adhesives. In this work, biomineral-reinforced biopolymer adhesives were produced by ureolytically induced precipitation of calcium carbonate in the presence of guar gum and soy protein. The microbially and enzymatically induced ureolysis was carried out by the ureolytic bacterium, Sporosarcina pasteurii, or by jack bean urease. The resulting adhesives were referred to as ureolytically induced calcium carbonate precipitation (UICP)-reinforced adhesives and specifically microbially and enzymatically induced calcium carbonate (MICP and EICP)- reinforced adhesives. The adhesive strength of these composite adhesives was optimized by varying calcium and cell (or enzyme) concentrations. The adhesive strength of biomineral reinforced guar gum and soy protein biopolymers was up to 2.5 and 6 times higher than the adhesive strength of the biopolymers alone, respectively. The durability of the MICP-reinforced adhesives was tested after varying immersions (24 h and 7 days), relative humidities (50 and 80% RH), and temperatures (-20, 100, and 300?C). The durability of the MICP-reinforced adhesives, upon immersion, was significantly improved compared to biopolymer alone, and maintained their adhesive strength at moderate humidities and from below-freezing to room temperatures after 7- day exposures. To determine the effect of biopolymers on the nanoscale material properties of biomineral aggregates, enzymatically induced calcium carbonate precipitation was induced in the presence of a standard protein, Bovine Serum Albumin (BSA). Nanoindentation and Atomic Force Microscopy show that the moduli of the mineral precipitates were significantly lowered in the presence of BSA. Atomic force microscopy also showed that BSA introduced structural variations and moduli gradation in biominerals. These results demonstrate that the presence of a protein additive, specifically BSA, can alter the nanoscale structure and material properties of calcium carbonate precipitates. Using an organic additive to manipulate microscale material properties of biominerals offers possibilities for advanced control at the microscale and enhanced toughness at the macroscale for engineering applications such as in construction, binder, and adhesive applications.Item Microbially induced calcium carbonate precipitation: meso-scale optimization and micro-scale characterization(Montana State University - Bozeman, College of Engineering, 2020) Zambare, Neerja Milind; Chairperson, Graduate Committee: Robin Gerlach and Ellen G. Lauchnor (co-chair); Ellen Lauchnor and Robin Gerlach were co-authors of the article, 'Controlling the distribution of microbially precipitated calcium carbonate in radial flow environments' in the journal 'Environmental science and technology' which is contained within this dissertation.; Robin Gerlach and Ellen Lauchnor were co-authors of the article, 'Spatio-temporal dynamics of strontium partitioning with microbially induced calcium carbonate precipitation in porous media flow cells' submitted to the journal 'Environmental science & technology' which is contained within this dissertation.; Robin Gerlach and Ellen Lauchnor were co-authors of the article, 'Co-precipitation of strontium and barium' submitted to the journal 'Environmental science & technology' which is contained within this dissertation.; Nada Naser, Robin Gerlach and Connie Chang were co-authors of the article, 'Visualizing microbially induced mineral precipitation from single cells using drop-based microfluidics' submitted to the journal 'Nature methods' which is contained within this dissertation.Microorganisms have the potential to impact processes on a scale orders of magnitude larger than their size. For example, microbe-mineral interactions at the micro-scale can drive macro-scale processes such as rock formation and weathering. Many bioremediation technologies derive inspiration from microbial mineralization processes. Microbially induced calcium carbonate precipitation (MICP) can produce calcium carbonate (CaCO 3) precipitates which can be utilized as a biological cement to strengthen porous media by reducing fluid permeability in subsurface fractures or as an immobilization matrix to remove metal contaminants dissolved in groundwater. To make MICP a feasible and successful bioremediation technology in the world outside the lab, it is necessary to bridge the gap between the meso-scale research studies and macro-scale applications. This thesis focuses on such meso-scale studies but also contributes to bridging the gap in the other direction, i.e., meso-scale to micro-scale to gain a fundamental understanding of the cellular level processes behind MICP. The research presented here investigates two applications of MICP with a focus on controlling precipitate distribution and process efficiency in target environments. Subsurface precipitate distribution and metal partitioning during MICP were studied in novel reactive transport systems that mimic application-environment conditions. A radial flow reactor was used to study the spatial distribution of precipitates in conditions similar to subsurface injection well environments. The distribution and degree of metal partitioning during MICP was investigated in batch reactors and porous media flow cells to study kinetics and reactive transport effects on kinetics. In the radial flow environment, more precipitates formed away from the center injection zone. Results showed that longer reactant residence times and an equimolar ratio of calcium to urea were able to maximize precipitation efficiency. Metal partitioning could be maximized at low reactant flow rates and low metal concentrations. The novel flow cell set up used revealed a spatial decoupling between ureolysis and precipitation. A micro-scale investigation of the fundamental MICP process itself is presented wherein microbe-mineral interactions are observed at the cell level. A semi-correlative approach to investigating individual precipitates in microdroplets is presented, using a multitude of microscopy and microanalysis techniques. The presented studies capture MICP across a range of scales.Item Urease immobilization for advancing enzyme-induced calcium carbonate precipitation applications(Montana State University - Bozeman, College of Engineering, 2019) Frieling, Zachary James; Chairperson, Graduate Committee: Robin Gerlach and Adrienne Phillips (co-chair)Microbially induced calcium carbonate precipitation (MICP) is a widely studied field of research exploiting bacterial activity to form a calcium carbonate precipitate that has been used to modify porous media. MICP is an enzymatically driven process and uses the enzyme urease to change solution chemistry to favor calcium carbonate precipitation. An enzyme slurry can be used in lieu of microbial growth and can be applied in a similar fashion and is commonly referred to as enzymatically induced calcium carbonate precipitation (EICP). For some applications temperature can stunt microbial growth and EICP may be the preferred method. However, as the temperature increases further the urease enzyme is thermally inactivated inhibiting calcium carbonate precipitation. Thermal inactivation limits the potential use of EICP in higher temperature environments. To combat thermal inactivation, immobilization of the urease enzyme through entrapment in silica gel and adsorption on an internally porous ceramic proppant was evaluated, and the first order inactivation coefficient (kd) was determined for temperatures between 60°C and 90°C. It was found that immobilization of the urease enzyme drastically reduced the apparent k d when compared to the free, non-immobilized form. Column experiments were performed using the urease immobilized on the ceramic proppant at room temperature (~23°C) and at 60°C. It was found that the immobilized urease retained high activity for the duration of the experiments even when subjected to the elevated temperature condition. The immobilized form of the urease enzyme was indeed protected from thermal degradation. It also seemed that the immobilized form of the urease enzyme was shielded from inactivation from active calcium carbonate precipitation, as observed in previous EICP and MICP experiments, in which ureolytic activity decreased rapidly as calcium carbonate precipitated. As a result, the immobilized form of the urease enzyme showed promise for advancing EICP applications.Item A study of bio-mineralization for the application of reducing leakage potential of geologically stored CO 2(Montana State University - Bozeman, College of Engineering, 2019) Daily, Ryanne Leigh; Chairperson, Graduate Committee: Adrienne PhillipsA primary concern of carbon capture and storage (CCS) is leakage of the stored carbon dioxide (CO 2) from the subsurface back to the surface. To ensure long term storage of the CO 2, mitigation strategies are being developed to seal high permeability regions, such as fractures present in the caprock or the near wellbore environment. Ureolysis induced calcium carbonate precipitation (UICP) is a widely investigated technology utilizing the enzymatically driven process of ureolysis to alter the properties of porous media. The advantage of this technology over traditional fracture sealing methods, such as well cement, is the use of low-viscosity aqueous fluids enabling access to smaller fractures. However, CCS reservoirs provide a problematic environment for microbial activity due to the acidity of dissolved CO 2, high pressures, and elevated temperatures. A flow-through pressurized reactor experiment and batch high-pressure ureolysis rate experiments were conducted to investigate the application of UICP technology to mitigate CO 2 migration. First, UICP was induced in two composite rock cores in an environment simulating a CCS reservoir, using a high-pressure axial flow reactor, with an initial and final exposure of the rock cores to a carbonated brine. As a result of UICP, the apparent permeability of the rock cores were reduced by 5-orders of magnitude. The CO 2 challenge increased apparent permeability by 4-orders of magnitude, likely due to a preferential flow path created through the calcium carbonate (CaCO 3) seal, which was found with X-ray microcomputed tomography (micro-CT) imaging. The porosity of the composite rock cores was assessed throughout the experiment with two non-invasive technologies, micro-CT and nuclear magnetic resonance (NMR), both reported a significant decrease in porosity due to UICP and a slight increase after the CO 2 exposure. Second, ureolysis kinetics were assessed in the presence of a pressurized carbonated brine at pressures between 0 and 4 MPa. The kinetic studies were performed in a high-pressure batch reactor connected to high-pressure pH and conductivity probes. Samples could not be taken from the batch reactor without losing pressure; thus, conductivity was used as a surrogate measurement for urea concentration. It was found that, for the pressures tested, JBM urease was capable of hydrolyzing urea in the presence of a pressurized carbonated brine. It was also hypothesized that the rate observed at each experimental pressure may have been dependent on the buffered pH of the system. The combination of these studies suggests that, if the challenge of dissolution could be overcome, bio-mineralization may be used to enhance CCS by reducing the permeability of CO 2 leakage pathways.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 Visualizing and quantifying biomineralization in wellbore analog reactors(Montana State University - Bozeman, College of Engineering, 2017) Norton, Drew Owen; Chairperson, Graduate Committee: Adrienne PhillipsSubsurface fluid injection is a proposed method for the storage of hydrocarbon fuels and the mitigation of fossil fuel emissions. Concerns about leakage exist when storing fluids in the subsurface given their potential to damage functional groundwater aquifers or be emitted to the atmosphere. Defects detrimental to the integrity of subsurface storage systems can occur in and around the wellbore, thus fluid storage systems are heavily dependent on the cement surrounding the wellbore to maintain a seal. A method proposed to seal defects in the subsurface is Microbially Induced Calcium Carbonate Precipitation (MICP). MICP is a technique that uses low viscosity fluids and microorganisms (~2 microns diameter) to seal defects troublesome to subsurface fluid storage. In the MICP process, microorganisms such as Sporosarcina pasteurii that contain the enzyme urease catalyze the hydrolysis of urea to produce ammonium and carbonate species. When this process occurs in the presence of dissolved calcium, calcium carbonate may precipitate. To study MICP in defects common to the wellbore, two reactors systems were created. The first was constructed to mimic the geometry of the wellbore and allowed the visual observation of MICP formation. The second quantified MICP in a cement channel defect using X-ray computed microtomography. A reduction in apparent permeability and void fraction was observed in both systems, demonstrating the ability of MICP to restrict fluid flow in defects common to the wellbore. Observations made during these experiments will aid in improving the safety and efficacy of subsurface fluid storage systems.Item Biofilm-induced carbonate precipitation at the pore-scale(Montana State University - Bozeman, College of Engineering, 2015) Connolly, James Martin; Chairperson, Graduate Committee: Robin Gerlach; Robin Gerlach was a co-author of the article, 'Microbially induced carbonate precipitation in the subsurface: fundamental reaction and transport processes' in the book 'Handbook of Porous Media, 3rd Ed.' which is contained within this thesis.; Megan Kaufman, Adam Rothman, Rashmi Gupta, George Redden, Martin Schuster, Frederick Colwell and Robin Gerlach were co-authors of the article, 'Construction of two ureolytic model organisms for the study of microbially induced calcium carbonate precipitation' in the journal 'Journal of microbiological methods' which is contained within this thesis.; Benjamin Jackson, Adam P. Rothman, Isaac Klapper and Robin Gerlach were co-authors of the article, 'Estimation of a biofilm-specific reaction rate: kinetics of bacterial urea hydrolysis in a biofilm' submitted to the journal 'NPJ biofilms and microbiomes' which is contained within this thesis.; Johannes Hommel and Robin Gerlach were co-authors of the article, 'Reactive transport and permeability reduction in a synthetic 2D porous medium with biofilm-induced carbonate precipitation' which is contained within this thesis.There are many methods available to decrease permeability in the subsurface but one that has been the subject of much research over the last decade is microbially-induced carbonate precipitation (MICP). In this process, microbial activity is promoted that increases pore water alkalinity. When calcium or other divalent cations are supplied to the system, solid carbonate minerals can form which occupy pore space and can decrease permeability. Permeability reduction can also come from microbial biofilms forming in the pore space. The goal of the work presented in this dissertation is to understand how pore space is affected, both physically and chemically, by biofilms and the precipitates that they can form. Fundamental research presented here is intended to inform ongoing application-based research and development. Previously it has been a challenge to image MICP at high resolution without the use of destructive techniques. To overcome that obstacle, a fluorescently-tagged bacterium capable of urea hydrolysis-driven MICP was constructed. Biofilms were grown in two-dimensional microscale porous media reactors and allowed to precipitate calcium carbonate under varied conditions. These reactors were imaged noninvasively using confocal microscopy so that both biofilms and carbonate minerals could be resolved at micrometer resolution. Image analysis was utilized to quantify how much pore space was occupied by the biofilm and minerals in order to estimate porosity reduction. Finally, pore-scale reactive transport modeling was utilized in order to estimate local concentrations within the reactors. The results show that the extent to which the porosity and permeability of the porous medium was decreased depended on when the calcium was added to the system. Also, periods of low flow were found to decrease porosity and permeability to a greater extent. This result adds to the evidence that a pulsed flow injection strategy may be most effective for permeability reduction via MICP in the subsurface. Additionally, reactive transport modeling predicts a heterogeneous mineral saturation environment at the pore-scale which highlights the challenge of predicting precipitation behavior in Darcy-scale reactive transport models.