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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 Comparing the mechanical properties of shale cores: intact vs. fractured and sealed with UICP(Montana State University - Bozeman, College of Engineering, 2023) Bedey, Kayla Marjorie; Chairperson, Graduate Committee: Catherine Kirkland; This is a manuscript style paper that includes co-authored chapters.Fractures in subsurface shale formations are instrumental in the recovery of hydrocarbon resources. A result of hydraulic fracturing, these fractures have the potential to become harmful leakage pathways that may contribute undesired fluids to the atmosphere and functional groundwater aquifers. Ureolysis-induced calcium carbonate precipitation (UICP) is a biomineral solution where the urease enzyme converts urea and calcium into calcium carbonate mineral. The resulting biomineral can bridge gaps in fractured shale, reduce undesired fluid flow through leakage pathways, limit fracture propagation, better store carbon dioxide, and potentially extend the efficiency of future and existing wells. The mechanical properties of fractured shale sealed with UICP was investigated using a modified Brazilian indirect tensile strength test. Part one of this study investigated the tensile strength of shale rock using intact Eagle Ford (EF) and Wolfcamp (WC) shale cores (5.08 cm long by 2.54 cm diameter) tested at room temperature (RT) and 60°C. Results show no significant difference between shale types (average tensile strength = 6.19 MPa). EF cores displayed a higher strength at RT versus 60°C, but no difference was seen between temperatures for WC cores. Part two used UICP to seal shale cores (5.08 cm long by 2.54 cm diameter) with a single, heterogeneous fracture spanning the core length. UICP was delivered two ways: 1) the flow-through method injected 20-30 sequential patterns of microbes and UICP-promoting fluids into the fracture until fracture permeability reduced by three orders of magnitude and 2) the immersion method placed cores treated with guar gum and UICP-promoting solutions into a batch reactor, demonstrating that guar gum is a suitable inclusion to UICP-technology and may be capable of reducing the number of injections required in flow-through methodology. Tensile results for both flow-through and immersion methods were widely variable (0.15 - 8 MPa), and in some cores the biomineralized fracture split apart. Notably in other cores the biomineralized fracture remained intact, demonstrating more cohesion than the surrounding shale, indicating that UICP may produce a strong seal for subsurface application.Item Investigation of microbially induced carbonate precipitation for mitigation of acid mine drainage from coal mining waste(Montana State University - Bozeman, College of Engineering, 2023) Delwiche, Jenna Anne; Chairperson, Graduate Committee: Ellen G. Lauchnor; Adrienne J. Phillips (co-chair); This is a manuscript style paper that includes co-authored chapters.Acid Mine Drainage (AMD) is a serious environmental concern associated with coal mining. Many of the existing methods for addressing AMD are costly and focus on clean-up rather than prevention. In this study, the feasibility of using microbially induced carbonate precipitation (MICP) as an alternative method for mitigating environmental impacts from coal mining waste rock was investigated using laboratory scale experiments. Flow-through column testing showed that MICP can be used to create a calcium carbonate coating on coal waste rock, acting as a barrier between the rock and water. This treatment increased leachate pH, and microscopic inspection indicated that the presence of live bacteria was important for creating a durable coating. The MICP treatment decreased concentrations of heavy metals such as aluminum, barium, beryllium, copper, nickel, zinc, and iron in the leachate, but increased concentrations of vanadium, selenium, molybdenum, uranium, and arsenic. These results indicate that MICP may be an effective technique for mitigating AMD, but additional laboratory and field testing is needed to assess the feasibility of this treatment technology.Item Feasibility study for field-scale use of Ureolysis-Induced Calcite Precipitation (UICP) for roadbed improvement(Montana State University - Bozeman, College of Engineering, 2023) Dorian, Hudson Thomas; Chairperson, Graduate Committee: Mohammad Khosravi; Adrienne J. Phillips (co-chair); This is a manuscript style paper that includes co-authored chapters.A series of tests were conducted to evaluate the feasibility of using ureolysis-induced calcium carbonate precipitation (UICP) to improve the strength of the soil layers used to in the construction of roads. This process involved three series of tests conducted on soil specimens of gradually increasing volume. The first series regarded the relative effect of treatment direction, comparing top-down treatment to bottom-upwards and alternating treatment methods on 50-by-100-millimeter soil columns. This was evaluated through unconfined compressive strength (UCS) and the calcium carbonate distribution over the length of the soil, finding that all methods generated a reliable increase in the strength of the soil specimen. This phase of research also included a batch study, evaluating the growth of the ureolytic bacteria Sporosarcina pasteurii in a solution composed of commercially available ingredients, showing that the bacteria could be cultured at a far lower cost (as low as 20 cents per liter) than with lab-grade ingredients ($2.66 per liter). The next series of tests compared the effect of applying treatment solutions to the soil surface directly and using a probe to inject solutions beneath the surface. This was done with 15-centimeter, cylindrical specimens, evaluated through the California bearing ratio (CBR) test. It was determined that the treatment process had the capacity to increase the CBR value substantially (from ~11% up to 188%), and it was suggested that each treatment mechanism resulted in a predictable distribution of calcium carbonate. There was also success in using alternative, commercially-sourced ingredients to facilitate the treatment and improve the CBR value. The last tests centered on the treatment of a 30-centimeter-by-30-centimeter mock road section, combining the treatment mechanisms used at the 15-centimeter-scale to facilitate an increase in the CBR of a soil layer under pavement. Through UICP, the CBR value of this layer was successfully increased.Item Effect of bio-cementation on thermal properties of silty sand(Montana State University - Bozeman, College of Engineering, 2022) Gunyol, Pinar; Chairperson, Graduate Committee: Mohammad KhosraviIn recent years, there has been an increasing interest in the use of biological technologies in geotechnical engineering to improve thermal properties of geomaterials. Urea hydrolysis is a chemical reaction which can generate favorable conditions that result in the precipitation of calcium carbonate. Certain microbes or plant sources produce the urease enzyme which catalyzes the hydrolysis of urea to form carbonate (CaCO 3) to bond soil particles. Cementation located between the grain particles acts as a highly conductive heat transfer path by increasing the contact area between the sand particles. In this thesis, the applicability of bio-cementation via microbially induced calcite precipitation (MICP) on silty sand specimens with different fines contents of 0%, 5%, and 15% were investigated. MICP promoting fluids were injected into sand-filled columns and the resulting calcium conversion was measured. At the end of the injections, the MICP treated specimens were tested for cementation uniformity. The amount of precipitated CaCO 3 gradually decreased as the distance from the injection ports increases. The observed bio-cementation distribution could be attributed to the filtration of bacterial cells through the soil particles. The resulting effect of filtration on CaCO 3 distribution was observed to be more prominent for silty sands, presumably due to the presence of fine grains. Thermal conductivity measurements were assessed after each pulse during the MICP treatment using a TR-3 sensor. Under the saturated and untreated conditions, thermal conductivity increased with increasing fines content. In addition, MICP treatment can increase the thermal conductivity of saturated silty sands with the increasing number of treatment pulses. An increase of about 18% in thermal conductivity of the soil was achieved at an average CaCO 3 content of 10.7% presumably due to the formation of calcium carbonate bridges binding the soil grains together. The results presented herein suggests that MICP treatment can be a viable option to increase the thermal conductivity of soils in the range of fines content studied here (less than 15%). The findings of this research could be used to improve the efficiency of geothermal boreholes and other energy geo-structures using MICP by improving thermal conductivity of dry and partially saturated soil.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.