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Description
The goal of this research was to study the effect of dilution on ammonium and potassium removal from real hydrolyzed urine. The performance of two natural zeolites, clinoptilolite and chabazite, was studied and compared with the help of batch equilibrium experiments at four dilution levels: 100%, 10%, 1% and 0.1% (urine volume/total solution volume). Further, the sorption behavior of other exchangeable ions (sodium, calcium and magnesium) in clinoptilolite and chabazite was studied to improve the understanding of ion exchange stoichiometry. Ammonium and potassium removal were highest at undiluted level in samples treated with clinoptilolite. This is a key finding as it illustrates the benefit of urine source separation. Chabazite treated samples showed highest ammonium and potassium removal at undiluted level at lower doses. At higher doses, potassium removal was similar in undiluted and 10% urine solutions whereas ammonium removal was the highest in 10% urine solutions. In general, chabazite showed higher ammonium and potassium removal than clinoptilolite. The result showed that ion exchange was stoichiometric in solutions with higher urine volumes.
ContributorsRegmi, Urusha (Author) / Boyer, Treavor H (Thesis advisor) / Delgado, Anca G (Committee member) / Hamilton, Kerry (Committee member) / Arizona State University (Publisher)
Created2019
Description
This research aims to develop an understanding of how interventions designed to improve water quality in buildings can be used to mitigate Legionella pneumophila concentrations. Intervention methods can be described as any approach that can be used to improve microbial water quality. In order to provide a foundation of background knowledge, a literature review was conducted to identify similar studies and collect relevant and timely research similar to the subject. The information gathered from the literature review was used to structure the sampling process and parameters. Using the research collected from the literature review, a review table was created to summarize the differences in the studies conducted and to determine research gaps. To categorize the studies, intervention methods, contaminants addressed, and water quality meta-data were differentiated for each of the articles. For the purpose of the sampling process, the three interventions analyzed consist of flushing, water heater set point change, and both flushing and water heater set point change. The locations of the sampling consisted of the city drinking water inlet, the basement janitor's closet, basement shower, 2nd floor, 3rd floor, and 7th floor break rooms and restrooms of the Interdisciplinary Science and Technology Building IV at ASU. For the flushing intervention, the sampling results demonstrated an increase in free and total chlorine concentration post flushing which aligns with the research found in the literature review. In addition, it was observed that iron concentrations drastically increased for both the cold and hot water by flushing. There was a significant decrease detected for ATP concentrations post flush in the hot line. However through the sampling session, the flushing intervention did not yield statistically significant results for Legionella concentrations.
ContributorsCahill, Molly (Author) / Call, Kathryn (Co-author) / Johnson, Elizabeth (Co-author) / Kotta, Vishnu (Co-author) / Hamilton, Kerry (Thesis director) / Boyer, Treavor (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainable Engineering & Built Envirnmt (Contributor)
Created2023-05
Description
This study investigated the difference in biofilm growth on pristine and aged polypropylene microplastics exposed to Tempe Town Lake water for 8 weeks. The research question here is, does the aging of microplastic (MPs) change the biofilm formation rate and composition of the biofilm in comparison with the pristine MPs. To answer this question, the biofilm formation was quantified using different methods over time for both pristine polypropylene and aged polypropylene using agar plate counts and crystal violet staining. Colony counts based on agar plating showed an increase in microbial growth over the 8 weeks of treatment, with the aged MPs accumulating higher microbial counts than the pristine MPs. The diversity of the biofilm decreased over time for both MPs and the aged MPs had overall less diversity in biofilm, based on phenotype enumeration, in comparison with the pristine MPs. Higher biofilm growth on aged MPs was confirmed using crystal violet staining, which stains the negatively charged biological compounds such as proteins and the extracellular polymeric substance matrix of the biofilm. Using this complementary approach to colony counting, the same trend of higher biofilm growth on aged MPs was found. Further studies will focus on confirming the phenotype findings using microbiome analysis following DNA extraction. This project created a methodology to quantify biofilm formation on MPs, which was used to show that MPs may accumulate more biofilms in the environment as they age under sunlight.
ContributorsMushro, Noelle (Author) / Perreault, Francois (Thesis advisor) / Hamilton, Kerry (Committee member) / Krajmalnik-Brown, Rosa (Committee member) / Arizona State University (Publisher)
Created2022
Description
Zero-Valent Metals (ZVM) are highly reactive materials and have been proved to be effective in contaminant reduction in soils and groundwater remediation. In fact, zero-Valent Iron (ZVI) has proven to be very effective in removing, particularly chlorinated organics, heavy metals, and odorous sulfides. Addition of ZVI has also been proved in enhancing the methane gas generation in anaerobic digestion of activated sludge. However, no studies have been conducted regarding the effect of ZVM stimulation to Municipal Solid Waste (MSW) degradation. Therefore, a collaborative study was developed to manipulate microbial activity in the landfill bioreactors to favor methane production by adding ZVMs. This study focuses on evaluating the effects of added ZVM on the leachate generated from replicated lab scale landfill bioreactors. The specific objective was to investigate the effects of ZVMs addition on the organic and inorganic pollutants in leachate. The hypothesis here evaluated was that adding ZVM including ZVI and Zero Valent Manganese (ZVMn) will enhance the removal rates of the organic pollutants present in the leachate, likely by a putative higher rate of microbial metabolism. Test with six (4.23 gallons) bioreactors assembled with MSW collected from the Salt River Landfill and Southwest Regional Landfill showed that under 5 grams /liter of ZVI and 0.625 grams/liter of ZVMn additions, no significant difference was observed in the pH and temperature data of the leachate generated from these reactors. The conductivity data suggested the steady rise across all reactors over the period of time. The removal efficiency of sCOD was highest (27.112 mg/lit/day) for the reactors added with ZVMn at the end of 150 days for bottom layer, however the removal rate was highest (16.955 mg/lit/day) for ZVI after the end of 150 days of the middle layer. Similar trends in the results was observed in TC analysis. HPLC study indicated the dominance of the concentration of heptanoate and isovalerate were leachate generated from the bottom layer across all reactors. Heptanoate continued to dominate in the ZVMn added leachate even after middle layer injection. IC analysis concluded the chloride was dominant in the leachate generated from all the reactors and there was a steady increase in the chloride content over the period of time. Along with chloride, fluoride, bromide, nitrate, nitrite, phosphate and sulfate were also detected in considerable concentrations. In the summary, the addition of the zero valent metals has proved to be efficient in removal of the organics present in the leachate.
ContributorsPandit, Gandhar Abhay (Author) / Cadillo – Quiroz, Hinsby (Thesis advisor) / Olson, Larry (Thesis advisor) / Boyer, Treavor (Committee member) / Arizona State University (Publisher)
Created2019
Description
Humans are exposed up to thousands of per- and polyfluoroalkyl substances (PFAS) in the environment, but most of the research and action has been directed towards only two PFAS compounds. These two compounds are part of a subcategory of PFAS called perfluoroalkyl acids (PFAAs). It has been a challenge for the environmental community to mitigate risks caused by PFAAs due to their high persistence and lack of effective measures to remove them from the environment, especially in heavily impacted areas like fire-training sites. The goal of this work was to further answer some questions regarding the removal of PFAAs in the environment by looking at anion exchange resin characteristics and presence of a competing compound, natural organic matter (NOM), in the adsorption of environmentally relevant PFAS compounds including the two often monitored 8-carbon chain PFAAs. Two different resins were tested with two forms of counterions, in both groundwater and NOM impacted groundwater. Resin polymer matrix was the most important property in the adsorption of PFAAs, the two resins used A520E and A860 had similar properties except for their matrices polystyrene (PS) and polyacrylic (PA), respectively. The PS base is most effective at PFAAs adsorption, while the PA is most effective at NOM adsorption. The change in the counterion did not negatively affect the adsorption of PFAAs and is, therefore, a viable alternative for future studies that include regeneration and destruction of PFAAs. The presence of NOM also did not significantly affect the adsorption of PFAAs in the PS resin A520E, although for some PFAAs compounds it did affect adsorption for the PA resin. Ultimately, PS macroporous resins with a strong Type I or Type II base work best in PFAAs removal.
Contributorsdel Moral, Lerys Laura (Author) / Boyer, Treavor (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Hamilton, Kerry (Committee member) / Arizona State University (Publisher)
Created2019
Description
Water reuse and nutrient recovery are long-standing strategies employed in agricultural systems. This is especially true in dry climates where water is scarce, and soils do not commonly contain the nutrients or organic matter to sustain natural crop growth. Agriculture accounts for approximately 70% of all freshwater withdrawals globally. This essential sector of society therefore plays an important role in ensuring water sources are maintained and that the food system can remain resilient to dwindling water resources. The purpose of this research is to quantify the benefits of organic residuals and reclaimed water use in agriculture in arid environments through the development of a systematic review and case study. Data from the systematic review was extracted to be applied to a case study identifying the viability and benefits of organic residuals on arid agriculture. Results show that the organic residuals investigated do have quantitative benefits to agriculture such as improving soil health, reducing the need for conventional fertilizers, and reducing irrigation needs from freshwater sources. Some studies found reclaimed water sources to be of better quality than local freshwater sources due to environmental factors. Biosolids and manure are the most concentrated of the organic residuals, providing nutrient inputs and enhancing long-term soil health. A conceptual model is presented to demonstrate the quantitative benefits of using a reclaimed water source in Pinal County, Arizona on a hypothetical crop of cotton. A goal of the model is to take implied nutrient inputs from reclaimed water sources and quantify them against standard practice of using irrigated groundwater and conventional fertilizers on agricultural operations. Pinal County is an important case study area where farmers are facing cuts to their water resources amid a prolonged drought in the Colorado River Basin. The model shows that a reclaimed water source would be able to offset all freshwater and conventional fertilizer use, but salinity in reclaimed water sources would force a need for additional irrigation in the form of a large leaching fraction. This review combined with the case study demonstrate the potential for nutrient and water reuse, while highlighting potential barriers to address.
ContributorsKrukowski, William Lee (Author) / Muenich, Rebecca (Thesis advisor) / Williams, Clinton (Committee member) / Hamilton, Kerry (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2020
Description
This dissertation focused on the implementation of urine diversion systems in commercial and institutional buildings in the United States with a focus on control of the urea hydrolysis reaction. Urine diversion is the process by which urine is separately collected at the source in order to realize system benefits, including water conservation, nutrient recovery, and pharmaceutical removal. Urine diversion systems depend greatly on the functionality of nonwater urinals and urine diverting toilets, which are needed to collect undiluted urine. However, the urea hydrolysis reaction creates conditions that lead to precipitation in the fixtures due to the increase in pH from 6 to 9 as ammonia and bicarbonate are produced. Chapter 2 and Chapter 3 describes the creation and use of a cyber-physical system (CPS) to monitor and control urea hydrolysis in the urinal testbed. Two control logics were used to control urea hydrolysis in realistic restroom conditions. In the experiments, acid was added to inhibit urea hydrolysis during periods of high and low building occupancy. These results were able to show that acid should be added based on the restroom use in order to efficiently inhibit urea hydrolysis.
Chapter 4 advanced the results from Chapter 3 by testing the acid addition control logics in a real restroom with the urinal-on-wheels. The results showed that adding acid during periods of high building occupancy equated to the least amount of acid added and allowed for urea hydrolysis inhibition. This study also analyzed the bacterial communities of the collected urine and found that acid addition changed the structure of the bacterial communities.
Chapter 5 showed an example of the capabilities of a CPS when implemented in CI buildings. The study used data mining methods to predict chlorine residuals in premise plumbing in a CI green building. The results showed that advance modeling methods were able to model the system better than traditional methods. These results show that CPS technology can be used to illuminate systems and can provide information needed to understand conditions within CI buildings.
ContributorsSaetta, Daniella (Author) / Boyer, Treavor H (Thesis advisor) / Hamilton, Kerry (Committee member) / Ross, Heather M. (Committee member) / Boscovic, Dragan (Committee member) / Arizona State University (Publisher)
Created2021