Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- All Subjects: Environmental engineering
Description
This dissertation applies wastewater-based epidemiology (WBE) to aqueous process flows to gauge the public health status concerning exposure and potential abuse of pharmaceuticals, antimicrobials, and narcotics. The masses of emerging contaminants emitted into Indian aquatic and terrestrial environments were the highest for open defecation (17 ± 12 mt/d), with non-steroidal anti-inflammatory drugs dominating environmental loading (14 ± 10 mt/d), followed by antibiotics, antimicrobials, phthalates and miscellaneous pharmaceuticals (Chapter 2). Fourteen wastewater treatment plants sampled across the U.S. had a combined average mass loading of 71 ± 12 µg/d/capita for the antimicrobials triclosan and triclocarban, with paraben compounds contributing 19 ± 5 µg/d/US capita. Risk models showed unfavorable hazard quotients (HQ>1) for sensitive aquatic organisms (algae, zebra fish and rainbow trout) from predicted exposures to antimicrobials of alternative use, i.e., chlorhexidine and benzalkonium chloride (Chapter 3). Substances subject to licit and illicit use, monitored by WBE in a medium-sized southwestern U.S. city before and during COVID-19-related lockdowns, showed the highest mass loads for cocaine and its major metabolite benzoylecgonine (2,207 total), methadone and its major metabolite 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (197), parent mitragynine (60), oxycodone and its major metabolite noroxycodone (48), heroin and its major metabolite 6-acetylmorphine (45), and parent codeine (37) in mg/1,000 capita/day. Heroin use during the lockdown increased ~10-fold relative to the pre-lockdown baseline, whereas oxycodone and codeine mass loading decreased 5-fold and 2.5-fold, respectively (Chapter 4). Experiments elucidating the stability of stress hormones and their metabolites as a function of temperature and in-sewer residence time revealed a rapid degradation to completion over 24 hours at 35°C, whereas lower temperatures of 25°C and 15°C were found to allow for successful tracking of indicators of stress at the population level; statistically significant differences in stress hormone decay rates were observed due to geographic locations at 25°C (p=0.009) but not due to redox conditions in the sewer pipe (Chapter 5). This thesis demonstrated the successful application of WBE for studying population health frequently and inexpensively, with the limitation that a lack of centralized wastewater infrastructure in developing countries may create barriers for at-risk populations to access and utilize this novel technology (Chapter 6).
ContributorsKelkar, Varun Pushkaraj (Author) / Halden, Rolf U (Thesis advisor) / Hamilton, Kerry A (Committee member) / Conroy-Ben, Otakuye (Committee member) / Arizona State University (Publisher)
Created2021
Description
The intent of this dissertation was to advance the knowledge of the impacts of building design and use on the quality of the potable water. Fluctuations in water use by occupants and equipment can cause stagnant conditions that causes water quality decay such as loss of chlorine disinfectant, an increase in microorganism and pathogen growth, an increase in metals concentrations, and an increase in disinfection byproducts. The United States Environmental Protection Agency has drinking water standards for distribution systems, but these standards stop at the meter with exception of the Lead and Copper Rule. There are also building codes to ensure proper plumbing materials are used that come in contact with potable water. However, neither standards nor codes require building water quality monitoring. Therefore, monitoring the building potable water system is an important aspect of building water quality that is not done on a large scale.Chapter 2 investigated how water quality evolved in a “green”, multi-story, institutional building during the first 6 months of building life. The results indicated that Wi-Fi logins could be used to correlate occupancy activity and copper (Cu) concentrations in water. As occupancy activity increased, Cu concentrations decreased. However, chlorine (Cl2) residual (or free chlorine) was only measurable twice at two kitchen sinks via grab sampling during the duration of the 6-month study regardless of occupancy activity.
Chapter 3 provided improved understanding of how to carry out effective building water sampling (e.g., grab samples vs real time) and which water quality parameters were most influenced by the building water system during the first year of occupancy in relation to municipal water quality. The results showed the temperature (T), pH, UVA254, a surrogate for organic matter, cellular adenosine triphosphate (cATP), trihalomethanes (THMs), and Cu were always greater inside the building than at building entry while free Cl2 was always lower inside the building than at the building entry.
Chapter 4 investigated a remedial flushing program for three schools. Overall, the study showed the quality of water does change after a flushing event. Free Cl2 was reestablished, and metals concentrations decreased. However, equipment flushing, such as hot water heaters, may be necessary to fully remediate Legionella. Lastly, one-time flushing is most likely a temporary solution. A more routine approach to building flushing and monitoring may be necessary until normal or sustained occupancy resumes.
ContributorsRichard, Rain (Author) / Boyer, Treavor H (Thesis advisor) / Hamilton, Kerry A (Committee member) / Ross, Heather M (Committee member) / Arizona State University (Publisher)
Created2021