Mycobacterium spp. Succession in a Premise Plumbing Pipe Rack: Evaluation of Predictive Factors

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Description
Waterborne opportunistic pathogens, particularly non-tuberculous mycobacteria(NTM), pose significant challenges to public health. This study aims to address critical gaps in understanding mycobacterial succession within premise plumbing systems, focusing on diversity, morphology, and factors influencing persistence. A premise plumbing pipe rack…

Waterborne opportunistic pathogens, particularly non-tuberculous mycobacteria(NTM), pose significant challenges to public health. This study aims to address critical gaps in understanding mycobacterial succession within premise plumbing systems, focusing on diversity, morphology, and factors influencing persistence. A premise plumbing pipe rack experiment was conducted with various pipe materials under real-world conditions. Water samples were collected and analyzed for NTM presence using culture-based and molecular techniques. During the cultivation of various isolates, two main morphologies were noted, revealing insights into the dynamics of mycobacterial communities within premise plumbing systems. Polymerase chain reaction (PCR) analysis attributed the yellow colonies to M. intracellulare or M. chimaera, while the white colonies represented unidentified mycobacterial species. The temporal dynamics of mycobacterial presence, assessed through PCR analysis over 7 weeks, demonstrated fluctuations influenced by source water conditions and disinfectant levels. Different pipe materials exhibited varying levels of mycobacterial colonization, with PVC pipes showing the highest percent positive. Species-level PCR analysis revealed dominance of M. intracellulare/M. chimaera in copper and PEX pipes, while "other" species were more prevalent in PVC pipes. The dominance of human-relevant species raises concerns for health, particularly among immunocompromised individuals. Future sequencing work is necessary to distinguish between M. intracellulare and M. chimaera, a differentiation that could provide valuable insights into the sources and transmission routes of these pathogens in the environment.
Date Created
2024
Agent

Sustainable Urban Wastewater Systems and Greywater Policy

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Description
This dissertation focuses on three studies related to sustainable urban wastewater systems and greywater policy. The research aims to address technical, regulatory, and social gaps in sustainable urban wastewater systems and greywater policy through research and innovation, adopting a holistic,…

This dissertation focuses on three studies related to sustainable urban wastewater systems and greywater policy. The research aims to address technical, regulatory, and social gaps in sustainable urban wastewater systems and greywater policy through research and innovation, adopting a holistic, systems perspective to realize the water security, environmental, and social benefits of greywater reuse. The main research question is: How can greywater treatment technologies and greywater reuse policies contribute to sustainable urban water systems based on the SETs (Social-Ecological-Technological Systems) framework?The first study conducted a systematic literature review of urban wastewater, covering historical sources, treatment technologies, recycling, and reuse. It summarized the theoretical framework based on the review and developed a conceptual framework for greywater treatment technologies based on the SETs framework, which can support the development of sustainable cities. The second study focused on the public perception of greywater reuse in Phoenix, Arizona, USA. Using a mix of qualitative and quantitative research methods, the study found that city residents have a strong positive perception of and support for greywater reuse, suggesting that the barriers and challenges of public perception can be overcome. The third study examined greywater reuse policies in Arizona and California. It interviewed residents and policymakers and conducted a policy analysis to reveal the implementation benefits, management obstacles, technical restrictions, and challenges of greywater reuse policies in the two states. The study provides recommendations for redesigning greywater policies and improving greywater reuse policies. The dissertation concludes that greywater reuse policies should be informed by the new knowledge from the three studies to establish sustainable water use practices and design greywater reuse regulations and technologies that encourage safe and responsible greywater reuse in urban design. It emphasizes the need to increase economic data on greywater use and public investment to provide better economic costs and benefits, which can help shift interest towards more supportive greywater policy changes. The dissertation highlights that greywater policy is a key factor affecting the sustainability of urban water systems and that greywater treatment technologies and policies can contribute to sustainable urban water systems by addressing the social, ecological, and technological aspects of urban water challenges, supporting the vision of resilient, inclusive, livable, and sustainable water-smart cities.
Date Created
2024
Agent

Anticipatory Life Cycle Assessment of Phosphorus Recovery from Human Urine and Application in Agricultural Food Systems

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Description
The escalating global demand for food production underscores the urgent need for sustainable agricultural innovations. This research contributes new insights into the environmental benefits of using urine-derived phosphorus (P) fertilizers by closing the nutrient loop and applying the technology to…

The escalating global demand for food production underscores the urgent need for sustainable agricultural innovations. This research contributes new insights into the environmental benefits of using urine-derived phosphorus (P) fertilizers by closing the nutrient loop and applying the technology to agricultural food systems. Anticipatory life cycle assessment was used to quantify the environmental impacts of replacing conventionally mined P fertilizer with recovered urine-derived P fertilizer within the production of beef and plant-based burgers. Results shows that implementing recovered P fertilizer provides greater environmental benefits for all environmental impact categories, with global warming, eutrophication, and water consumption being the main impact categories examined in this study. Urine-derived P fertilizer use in beef burger production led to a 4% reduction in global warming impacts (3% for plant-based), 15% reduction in eutrophication (2% for plant-based), and 42% reduction in water consumption (46% for plant-based). Uncertainty in the results was accounted for using Monte Carlo simulation with 10,000 runs to rank the four burger production scenarios (e.g., conventional and urine-derived beef burger and conventional and urine-derived plant-based burger) based on their environmental impact on global warming, eutrophication, and water use under conditions of baseline, realistic, and maximum uncertainty. Under conditions of realistic uncertainty, implementing urine-derived P fertilizer for beef burger production was considered beneficial for global warming, eutrophication, and water consumption, with 78%, 99%, and 89% of the runs showing environmental benefits, respectively. Due to the lower P fertilizer requirements in plant-based burger production, uncertainty assessment under realistic conditions showed that a reduction in water use was the only expected benefit of implementing recovered P fertilizer, with 71% of the runs providing water use benefits. These results show that closing the nutrient loop by implementing urine-derived P fertilizers can be beneficial when applied to the correct agricultural food system (e.g., beef burger production) and is expected to have the most pronounced benefits with regard to water savings.
Date Created
2024
Agent

Investigation of the Cotton Industry: Analysis of Its Water Consumption and Remediation Solutions for Water Consumption and Subsequent Pollutants

Description
Global water consumption is at record levels, prompting concerns about sources, treatment, shortages, accessibility, and environmental impacts. While residential use is high due to population growth, industrial activities, particularly in sectors like textiles, are major contributors to overconsumption and pollution.…

Global water consumption is at record levels, prompting concerns about sources, treatment, shortages, accessibility, and environmental impacts. While residential use is high due to population growth, industrial activities, particularly in sectors like textiles, are major contributors to overconsumption and pollution. The textile industry's emphasis on high-volume production, driven by capitalist economies and fueled by trends and social media, has led to increased consumption and waste, notably in the cotton sector, which has one of the highest water consumption rates. By investigating the three (3) top cotton-producing countries, an inference regarding global cotton production practices, water usage, and pollutant discharge was able to be made. These countries included India, China, and the United States. It was determined that the agricultural and post-harvest production conjointly sum to a water usage of about 10,000 m3 per ton. This includes water use for irrigation, various purification processes, serial dilutions for pollutants, cleansing, dyeing, and printing processes. In addition to high water consumption, the cotton industry is also a major source for pollution. These pollutants are due to many processes within the complete production process. The contaminants of concern within this investigation are azo dyes. These dyes are able to degrade into toxic byproducts called aromatic amines which are known to be carcinogenic, mutagenic, and irritating. They also reduce sunlight transmittance and increase the BOD and COD within aquatic ecosystems. Popular remediation methods include reverse osmosis, electrolysis, and biological decoloration – through fungi and prokaryotes – are used due to their high degradation efficiency of around 90%. Although this efficiency rate is quite high, a newer remediation method for azo dyes was found that has a 99.8% efficiency rate along with reusable materials. This process utilized silver nanoparticle-intercalated cotton fibers to completely remove the dyes from the tested waters. Through the investigation, inefficiencies and possible sustainability initiatives were determined that will hopefully become globally implemented in order to reduce the large impact of the cotton textile industry.
Date Created
2024-05
Agent

Phosphate Product Recovery in Human Urine using Metal Chlorides

Description
Phosphate is a necessary and soon to be scarce nutrient needed for all life that is found in urine. Metal chlorides can be used to extract phosphate that can be converted into useful products, namely struvite a fertilizer. Different metal…

Phosphate is a necessary and soon to be scarce nutrient needed for all life that is found in urine. Metal chlorides can be used to extract phosphate that can be converted into useful products, namely struvite a fertilizer. Different metal chlorides’ phosphate removal ability in urine were measured by testing a molar equivalent amount of metal chloride tested at 5 minutes and 24 hours in duplicate. Phosphate removal was calculated using spectrophotometry and compared across the metal chlorides in a simulation in Visual MINTEQ, simple synthetic, full synthetic, and real urine for fresh and hydrolyzed urine. It was found that simple and full fresh synthetic urine had comparable results, but synthetic urine and real urine did not. It was also found that simple and full hydrolyzed synthetic urine are not very comparable. Overall, there was more precipitation in the real urine than the full synthetic urine and hydrolyzed urine. Time did not have a large effect on the removal trends between the same type of urine. CeCl3 performed the best for both fresh and hydrolyzed urine, and struvite produced more in hydrolyzed real urine rather than fresh.
Date Created
2023-12
Agent

Proactive Real-time Control of Multiple Interdependent Water Quality Variables in Buildings Water Networks

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Description
Efforts to enhance the quality of life and promote better health have led to improved water quality standards. Adequate daily fluid intake, primarily from tap water, is crucial for human health. By improving drinking water quality, negative health effects associated…

Efforts to enhance the quality of life and promote better health have led to improved water quality standards. Adequate daily fluid intake, primarily from tap water, is crucial for human health. By improving drinking water quality, negative health effects associated with consuming inadequate water can be mitigated. Although the United States Environmental Protection Agency (EPA) sets and enforces federal water quality limits at water treatment plants, water quality reaching end users degrades during the water delivery process, emphasizing the need for proactive control systems in buildings to ensure safe drinking water.Future commercial and institutional buildings are anticipated to feature real-time water quality sensors, automated flushing and filtration systems, temperature control devices, and chemical boosters. Integrating these technologies with a reliable water quality control system that optimizes the use of chemical additives, filtration, flushing, and temperature adjustments ensures users consistently have access to water of adequate quality. Additionally, existing buildings can be retrofitted with these technologies at a reasonable cost, guaranteeing user safety. In the absence of smart buildings with the required technology, Chapter 2 describes developing an EPANET-MSX (a multi-species extension of EPA’s water simulation tool) model for a typical 5-story building. Chapter 3 involves creating accurate nonlinear approximation models of EPANET-MSX’s complex fluid dynamics and chemical reactions and developing an open-loop water quality control system that can regulate the water quality based on the approximated state of water quality. To address potential sudden changes in water quality, improve predictions, and reduce the gap between approximated and true state of water quality, a feedback control loop is developed in Chapter 4. Lastly, this dissertation includes the development of a reinforcement learning (RL) based water quality control system for cases where the approximation models prove inadequate and cause instability during implementation with a real building water network. The RL-based control system can be implemented in various buildings without the need to develop new hydraulic models and can handle the stochastic nature of water demand, ensuring the proactive control system’s effectiveness in maintaining water quality within safe limits for consumption.
Date Created
2023
Agent

UNDERSTANDING AND MANAGEMENT OF HOLISTIC WATER QUALITY AND LEGIONELLA IN BUILDING WATER SYSTEMS

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…

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.

Date Created
2023-05
Agent

UNDERSTANDING AND MANAGEMENT OF HOLISTIC WATER QUALITY AND LEGIONELLA IN BUILDING WATER SYSTEMS

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…

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.

Date Created
2023-05
Agent

Understanding and Management of Holistic Water Quality and Legionella in Building Water Systems

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…

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.

Date Created
2023-05
Agent

Numerical Simulation of Moisture Swing Absorption Model for Carbon Dioxide Capture

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Description
The current level of carbon dioxide in ambient air is increasing and reinforcing the severity of global warming. Several techniques have been developed to capture the gas directly from the air. Moisture swing absorption (MSA) is a mechanism through…

The current level of carbon dioxide in ambient air is increasing and reinforcing the severity of global warming. Several techniques have been developed to capture the gas directly from the air. Moisture swing absorption (MSA) is a mechanism through which a reactive surface, namely resin beads, absorbs carbon dioxide when dry and releases it when wet. The ionic complexity of the surface of the bead interacts with CO2 when H2O contents are low, and CO2 diffuses as bicarbonate or carbonate. Hence, diffusion-drift-reaction equations describe the moving species behavior MS sorbent. A numerical model has been developed previously applying finite difference scheme (FDS) to estimate the evolution of species concentrations over uniform time and space intervals. The methodology was based on a specific membrane and bead geometry. In this study, FDS was employed again with modifications over the boundary conditions. Neumann boundary condition was replaced by Robin boundary condition which enforced diffusion and drift fluxes at the center of the sorbent. Furthermore, the generic equations were approximated by another numerical scheme, Finite volume scheme (FVS), which discretizes the spatial domain into cells that conserves the mass of species within. The model was predicted to reduce the total carbon mass loss within the system. Both schemes were accommodated with a simulated model of isolated chamber that contained arbitrary sorbent. Moreover, to derive the outcomes of absorption/desorption cycles and validate the performance of FVS, Langmuir curve was utilized to obtain CO2 saturation in the sorbent and examine two scenarios: one by varying the partial pressure of CO2 (PCO2) in the chamber at constant H2O (PH2O), or changing PH2O at constant PCO2. The results from FDS approximation, when adjusting the center with Robin boundary condition, show 0.11% lower carbon mass gain than when applying Neumann boundary condition. On the other hand, FVS minimizes the mass loss by 0.3% lower than the original total carbon mass and achieves sorbent saturation without any adjustment. Moreover, the isotherm curve demonstrates that increasing PH2O reduces CO2 saturation and is dependent on the linear and non-linear correlations used to estimate water concentration on the surface.
Date Created
2021
Agent
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