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Item Removal of PFAS from synthetic wastewater using aerobic granular sludge(Montana State University - Bozeman, College of Engineering, 2023) Ritu, Tasnim Sultana; Co-chairs, Graduate Committee: Catherine KirklandThe project assesses the performance of the aerobic granular sludge (AGS) to remove poly- and per-fluoroalkyl substances (PFAS) and conventional nutrients like carbon, nitrogen, and phosphorus from synthetic wastewater in a sequencing batch reactor (SBR). AGS is an emerging wastewater treatment biofilm that may be effective in reducing the PFAS concentration in wastewater via sorption. PFAS are a class of man-made chemicals used as surfactants, fire retardants, and coating materials. PFAS compounds are very persistent in the environment and can lead to adverse health outcomes in humans. PFAS can migrate from consumer products and enter the influent of wastewater treatment plant (WWTP). PFAS compounds are poorly removed by conventional wastewater treatment methods making effluent from WWTP a significant source of PFAS in the environment. The project uses two specific PFAS which are perfluorooctanoic acid (PFOA) and perfluoro octane sulfonate acid (PFOS). Other objectives of this project are to monitor how PFAS influences the treatment of conventional wastewater constituents and the granules' structure and morphology. Two SBRs were started with floccular sludge from seed granules and continued for 402 days. Some standard laboratory analytical methods for nitrogen, phosphorus, and organic carbon were used to monitor the removal efficiencies of the granules. Solid phase extraction (SPE) and liquid chromatography with mass spectrometry (UPLC with ESI Q-TOF-MS) were used to assess the removal of PFOA and PFOS both from liquid and sludge phases. Maximum removal of 33% for PFOS and 28% for PFOA was achieved by AGS in the test SBR. PFOS/PFOA exposure affected the granule's physical properties, and the properties recovered within approximately 34 days of dosing. PFOS/PFOA contamination produced no significant effect on conventional nutrient removal except nitrification. Thus, the treatment of PFAS by AGS is economical, since AGS can treat several pollutants simultaneously in a single reactor. More research should be done on the disposal of PFAS-contaminated sludge and to increase the treatment efficiency.Item Assessing a novel approach to pharmaceutical removal from wastewater: aerobic granular sludge(Montana State University - Bozeman, College of Engineering, 2024) Bodle, Kylie Brigitta; Chairperson, Graduate Committee: Catherine Kirkland; This is a manuscript style paper that includes co-authored chapters.Pharmaceutical concentrations in various environmental matrices are increasing across the globe. Effluent discharge from wastewater treatment plants is a major vector by which pharmaceuticals enter the environment, as many of these compounds are not biodegradable under conventional wastewater treatment conditions. Although concentrations are currently low (ng/L to ?g/L levels), pharmaceutical contamination poses risks to both human and animal health, as many pharmaceuticals can have toxic effects on fish, birds, and small mammals, as well as contribute to the proliferation of antibiotic resistance genes in bacteria. Aerobic granular sludge (AGS), an emerging biofilm-based wastewater treatment biotechnology and the subject of this dissertation, may be capable of enhancing pharmaceutical removal from wastewater. Scientific literature indicates that AGS uses a mixture of both biodegradation and adsorption to remove pharmaceuticals, but thus far, studies on this topic are limited. The research detailed herein investigated how AGS was affected by a mixture of three common, but relatively unstudied, pharmaceuticals: diclofenac (anti-inflammatory), erythromycin (antibiotic), and gemfibrozil (lipid regulator). Studies described herein examined how AGS grown in two different environments--the lab versus a full-scale wastewater treatment plant--responded to pharmaceuticals. Pharmaceutical effects on wastewater treatment efficacy, active microbial populations, and biofilm structures were investigated. Pharmaceutical fates in both the aqueous and solid phases were also tracked. In general, lab-grown AGS was more negatively impacted by pharmaceutical exposure, evidenced by reduced wastewater treatment efficacy, declines in key wastewater-treating microbial populations, and reductions in biofilm lipid content. Pharmaceuticals were also poorly removed by lab-grown granules. In contrast, key microbial populations and biofilm structures remained stable throughout dosing in environmentally-grown AGS, and gemfibrozil was completely biodegraded. An important caveat to comparison of the two studies, however, is that the pharmaceutical dose to lab-grown AGS was approximately double that to environmental granules. Altogether, the research described herein demonstrates the promise of AGS as a dual wastewater and pharmaceutical treatment technology, but illustrates the importance of conducting experiments under conditions as environmentally relevant as possible.Item Evaluation of mixed-oxidants against sodium hypochlorite for the disinfection and removal of biofilms from distribution systems(Montana State University - Bozeman, College of Engineering, 1997) Crayton, Cynthia Lynn; Chairperson, Graduate Committee: Anne CamperProblem Statement: As drinking water regulations are applied to smaller utilities, an area of emerging concern for the water industry is the installation of disinfection systems to meet the newly imposed standards. Since traditional disinfection technologies are usually beyond the safety, economic, and/or site restraint considerations for small systems, an alternative is required. The mixed-oxidants disinfection system (MIOX) appears to provide a reasonable alternative for small distribution systems as a safe, reliable, and cost effective technology that is easy to operate and is readily compatible with other treatment systems. The goal of this five-phase study was to evaluate the potential of the MIOX disinfectant (produced on-site using feedstocks of ordinary salt, water, and twelve volt electricity) against free chlorine for biocidal efficacy, biofilm/biofouling removal, biofilm regrowth potential, relative corrosion potential, and cost effectiveness. Although mixed-oxidants have been proven effective in potable water disinfection, biofilm removal is a new application for this alternative disinfection technology.Item Modeling the non-linear response of mixed culture biofilm structures to turbulent flow(Montana State University - Bozeman, College of Engineering, 2004) Towler, Brett William; Chairperson, Graduate Committee: Ladean McKittrick.Microbial biofouling of wetted interfaces can negatively impact the hydrodynamic performance of pressurized conduits. These impacts are due, in part, to the material properties of biofilm, yet few studies have examined this polymeric substance in the context of a constitutive relation. The goal of this research was two-fold; 1) to determine a suitable constitutive model for a mixed-culture biofilm and 2) use this material model in a numerical simulation to evaluate biofilm mechanical behavior in response to varying hydrodynamic conditions. Creep tests revealed that these biofilms may be classified as viscoelastic fluids. Furthermore, results indicated the presence of viscous, time-dependent and instantaneous components to the biofilm compliance functions. A regression analysis (r2 = 0.8819) supported the treatment of these samples as linear viscoelastic fluids within the stress range of 0.1 Pa to 0.5 Pa. A specific linear viscoelastic constitutive equation was then determined by fitting experimental results to analytical solutions using an optimization algorithm. It was found that the Burger material model closely approximated the behavior of all samples. A numerical fluid-structure interface model was then developed and employed in a parametric study to investigate biofilm behavior. The effect of the Burger material parameters, mean flow velocity and biofilm size were examined. Simulations showed that weaker or softer biofilms (characterized by lower elastic moduli) were highly susceptible to lift forces. Additionally, polar diagrams were generated by plotting the coefficients of drag versus lift. The plots suggested that in the first few seconds after loading, the deformation paths taken by hemispherical biofilms are largely insensitive to specific material coefficients. Moreover, the diagrams illustrated that the effects of biofilm strength, size and channel velocity on displacement were predictable. These relationships may lead to the development of a simple, yet accurate method for predicting the hydrodynamic forces acting on an attached biofilm.Item Kinetics of biofilm growth and substrate uptake in model drinking water systems(Montana State University - Bozeman, College of Engineering, 1998) Butterfield, Phillip WesleyItem Rate and stoichiometry of sulfate reducing bacteria in suspended and biofilm cultures(Montana State University - Bozeman, College of Engineering, 1992) Okabe, SatoshiItem Interactions of 1 um latex microbeads with biofilms(Montana State University - Bozeman, College of Engineering, 1992) Drury, William JosephItem Factors influencing biofilm growth in drinking water distribution systems(Montana State University - Bozeman, College of Engineering, 1995) Camper, Anne KosteczkoItem Biocide action of chlorine on Pseudomonas aeruginosa biofilm(Montana State University - Bozeman, College of Engineering, 1991) Wende, Ewout van derItem The effect of corrosion control treatments and biofilm disinfection on unlined ferrous pipes(Montana State University - Bozeman, College of Engineering, 1998) Abernathy, Calvin Glenn