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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 Influence of dose volume on nitrogen removal in a two stage vertical flow treatment wetland: Bridger Bowl ski area case study(Montana State University - Bozeman, College of Engineering, 2023) Brush, Kristen Onofria; Chairperson, Graduate Committee: Otto SteinTreating wastewater in remote locations does not require compromising the effluent quality discharged to the environment. A two-stage vertical flow treatment wetland (VF TW) with recycle meets this objective by removing high inputs of chemical oxygen demand (COD) and nitrogen (N) while requiring minimal maintenance and operator oversight. A 95.2 m 2 pilot scale VF TW at Bridger Bowl Ski Area, near Bozeman, MT, effectively treats the high strength domestic wastewater produced onsite. The partially saturated first stage of the VF TW removes influent COD and an unsaturated second stage nitrifies influent ammonium. Recycling second stage effluent to the first stage allows for nitrate removal by denitrification in the saturated zone of the first stage. Previous research indicated the system experiences near complete nitrification in the second stage and that total nitrogen removal is limited by denitrification in the first stage, potentially due to low organic carbon (COD) availability in the saturated zone. Therefore, the goal of the current study was to increase the COD:N ratio of the water entering the first-stage saturated zone by increasing the dose depth of influent (septic) water, high in COD, thereby reducing COD removal in the unsaturated layer. To evaluate denitrification performance a simplified stoichiometric process model accounted for both nitrate created and COD removed in the first stage unsaturated zone. During the 21-22 season, approximately 7 cm/day of septic water was applied to the first stage in either 1.2 or 2.5 cm doses. The larger doses showed enhanced nitrate removal efficiency in the saturated zone; however, a changing influent water quality may have supplemented efficiency improvement. During the 22-23 season, 12 cm/day of septic water was applied to the first stage in either 1 or 4 cm doses. During this experiment, influent water quality was the same, and the larger dose depths did not show enhanced nitrate removal. However, decreasing the septic dose depth increased first stage nitrification from 20 to 48% and COD removal from 77 to 82%. Throughout both experiments, system COD removal was > 95% (influent COD > 750 mg/L) and system ammonia removal was > 98% (influent NH 4 >160 mg/L).Item Effects of hydraulic loading on nitrification and denitrification processes in a two-stage, vertical flow treatment wetland at Bridger Bowl Ski Area(Montana State University - Bozeman, College of Engineering, 2020) Panighetti, Robert Arthur; Chairperson, Graduate Committee: Otto SteinA pilot-scale two-stage vertical flow treatment wetland (VFTW) at the Bridger Bowl Ski Area was used to evaluate the influence of hydraulic loading rate on COD removal, nitrification, and denitrification in the system. Hydraulic loading rates ranged between 36 cm/d to 60 cm/d over system years 2018 and 2019. Total nitrogen loading (sum of NH 4+ and NO 3-) ranged from 12 g/m 2d to 65 g/m 2d, and COD loading ranged from 58 g/m 2d to 172 g/m 2d. The system effectively removed COD in both years, with removals of 95% and 96% for influent COD concentrations of 555 mg/L and 607 mg/L, respectively. Influent total nitrogen was 141 mg/L in 2018 and 105 mg/L in 2019, and removals were 67% and 54%, respectively. At a hydraulic loading rate of 60 cm/d, COD removal declined in the first stage and ammonium removal declined in the second stage. At lower hydraulic loading rates (up to 48 cm/d), removal of COD, ammonium and nitrate increased in a consistent pattern with increased mass loading of the respective contaminant, suggesting a maximum hydraulic loading rate limit between 48 and 60 cm/d. The effect of hydraulic loading cannot be completely separated from mass loading of a contaminant, likely influenced by the level of partial saturation within the first stage and the recycle ratio; neither were varied in this study. A key limiting factor is hydraulic overload to the first stage, limiting removal of COD which interfered with nitrification in the second stage. A multivariate model for ammonium removal in the second stage predicts increased ammonium removal with increasing ammonium load but decreasing COD load. Despite operational performance variation the system met applicable discharge requirements, reinforcing the ability of a VFTW system to perform secondary wastewater treatment, even for high-strength wastewater and in cold climates.