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- Creators: Arizona State University
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Description
As the use of engineered nanomaterials (ENMs) in consumer products becomes more common, the amount of ENMs entering wastewater treatment plants (WWTPs) increases. Investigating the fate of ENMs in WWTPs is critical for risk assessment and pollution control. The objectives of this dissertation were to (1) quantify and characterize titanium (Ti) in full-scale wastewater treatment plants, (2) quantify sorption of different ENMs to wastewater biomass in laboratory-scale batch reactors, (3) evaluate the use of a standard, soluble-pollutant sorption test method for quantifying ENM interaction with wastewater biomass, and (4) develop a mechanistic model of a biological wastewater treatment reactor to serve as the basis for modeling nanomaterial fate in WWTPs. Using titanium (Ti) as a model material for the fate of ENMs in WWTPs, Ti concentrations were measured in 10 municipal WWTPs. Ti concentrations in pant influent ranged from 181 to 3000 µg/L, and more than 96% of Ti was removed, with effluent Ti concentrations being less than 25 µg/L. Ti removed from wastewater accumulated in solids at concentrations ranging from 1 to 6 µg Ti/mg solids. Using transmission electron microscopy, spherical titanium oxide nanoparticles with diameters ranging from 4 to 30 nm were found in WWTP effluents, evidence that some nanoscale particles will pass through WWTPs and enter aquatic systems. Batch experiments were conducted to quantify sorption of different ENM types to activated sludge. Percentages of sorption to 400 mg TSS/L biomass ranged from about 10 to 90%, depending on the ENM material and functionalization. Natural organic matter, surfactants, and proteins had a stabilizing effect on most of the ENMs tested. The United States Environmental Protection Agency's standard sorption testing method (OPPTS 835.1110) used for soluble compounds was found to be inapplicable to ENMs, as freeze-dried activated sludge transforms ENMs into stable particles in suspension. In conjunction with experiments, we created a mechanistic model of the microbiological processes in membrane bioreactors to predict MBR, extended and modified this model to predict the fate of soluble micropollutants, and then discussed how the micropollutant fate model could be used to predict the fate of nanomaterials in wastewater treatment plants.
ContributorsKiser, Mehlika Ayla (Author) / Westerhoff, Paul K (Thesis advisor) / Rittmann, Bruce E. (Committee member) / Hristovski, Kiril D (Committee member) / Arizona State University (Publisher)
Created2011
Description
The Santa Cruz River, in southern Arizona, receives steady inputs of nutrient-enriched treated wastewater (effluent). Previous studies have documented reduced infiltration of surface water in the river. This disruption of hydrologic connectivity, or clogging, can have consequences for groundwater recharge, flows of wastewater in unwanted locations, and potentially even survivorship of floodplain riparian vegetation. Clogging can result from biotic processes (microbial or algal growth), abiotic processes (siltation of interstitial spaces), or both. Little is known about clogging in rivers and the environmental factors that regulate their dynamics, so natural field experiments along the Santa Cruz and San Pedro Rivers were used to answer: 1) Are there spatial patterns of hydraulic conductivity in the riverbed downstream from the effluent point-source? 2) Is there temporal variability in hydraulic conductivity and microbial abundance associated with flooding? 3) Are there environmental variables, such as nutrients or stream flow, related to differences in hydraulic conductivity and microbial abundance? To address these questions, a series of sites at increasing distance from two municipal effluent discharge points with differing water quality were selected on the Santa Cruz River and compared with non-effluent control reaches of the San Pedro River. Physical, chemical, and biological parameters were monitored over one year to capture seasonal changes and flood cycles.
ContributorsCase, Natalie (Author) / Stromberg, Juliet (Thesis advisor) / Rock, Channah (Committee member) / Meixner, Thomas (Committee member) / Arizona State University (Publisher)
Created2012
Description
Urban water systems face sustainability challenges ranging from water quality, leaks, over-use, energy consumption, and long-term supply concerns. Resiliency challenges include the capacity to respond to drought, managing pipe deterioration, responding to natural disasters, and preventing terrorism. One strategy to enhance sustainability and resiliency is the development and adoption of smart water grids. A smart water grid incorporates networked monitoring and control devices into its structure, which provides diverse, real-time information about the system, as well as enhanced control. Data provide input for modeling and analysis, which informs control decisions, allowing for improvement in sustainability and resiliency. While smart water grids hold much potential, there are also potential tradeoffs and adoption challenges. More publicly available cost-benefit analyses are needed, as well as system-level research and application, rather than the current focus on individual technologies. This thesis seeks to fill one of these gaps by analyzing the cost and environmental benefits of smart irrigation controllers. Smart irrigation controllers can save water by adapting watering schedules to climate and soil conditions. The potential benefit of smart irrigation controllers is particularly high in southwestern U.S. states, where the arid climate makes water scarcer and increases watering needs of landscapes. To inform the technology development process, a design for environment (DfE) method was developed, which overlays economic and environmental performance parameters under different operating conditions. This method is applied to characterize design goals for controller price and water savings that smart irrigation controllers must meet to yield life cycle carbon dioxide reductions and economic savings in southwestern U.S. states, accounting for regional variability in electricity and water prices and carbon overhead. Results from applying the model to smart irrigation controllers in the Southwest suggest that some areas are significantly easier to design for.
ContributorsMutchek, Michele (Author) / Allenby, Braden (Thesis advisor) / Williams, Eric (Committee member) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2012
Description
The reality of smart cities is here and now. The issues of data privacy in tech applications are apparent in smart cities. Privacy as an issue raised by many and addressed by few remains critical for smart cities’ success. It is the common responsibility of smart cities, tech application makers, and users to embark on the journey to solutions. Privacy is an individual problem that smart cities need to provide a collective solution for. The research focuses on understanding users’ data privacy preferences, what information they consider private, and what they need to protect. The research identifies the data security loopholes, data privacy roadblocks, and common opportunities for change to implement a proactive privacy-driven tech solution necessary to address and resolve tech-induced data privacy concerns among citizens. This dissertation aims at addressing the issue of data privacy in tech applications based on known methodologies to address the concerns they allow. Through this research, a data privacy survey on tech applications was conducted, and the results reveal users’ desires to become a part of the solution by becoming aware and taking control of their data privacy while using tech applications.
So, this dissertation gives an overview of the data privacy issues in tech, discusses available data privacy basis, elaborates on the different steps needed to create a robust remedy to data privacy concerns in enabling users’ awareness and control, and proposes two privacy applications one as a data privacy awareness solution and the other as a representation of the privacy control framework to address data privacy concerns in smart cities.
ContributorsMusafiri Mimo, Edgard (Author) / McDaniel, Troy (Thesis advisor) / Michael, Katina (Committee member) / Sullivan, Kenneth (Committee member) / Arizona State University (Publisher)
Created2022
Description
Corrosion is known to have severe infrastructure integrity implications in a broad range of industries including water and wastewater treatment and reclamation. In the U.S. alone, the total losses due to corrosion in drinking water and wastewater systems can account for economic losses as high as $80 billion dollars a year. Microbially induced corrosion is a complex phenomenon which involve various phases; 1) formation of biofilms on submerged surfaces, 2) creation of micro-environmental niches associated with biofilm growth, 3) altered availability nutrients, 4) changes in the pH and oxygen concentrations. Biofilms can harbor opportunistic or pathogenic bacteria for a long time increasing the risk of pathogen exposure for the end users. The focus of this thesis research was to study the kinetics of microbially induced corrosion of various materials in water and reclaimed water systems. The specific objective was to assess the biofilms formation potential on stainless steel 304, stainless steel 316, galvanized steel, copper, cPVC, glass, carbon steel, and cast iron in water and reclaimed water systems. Experiments were conducted using bioreactor containers, each bioreactor housed four sampling boxes with eight partitions, dedicated to each material type coupon. One bioreactor was stationed at ASU, and one at Vistancia Aquifer Storage and Recovery (ASR) well; while three bioreactors were stationed at Butler facility, at pre-disinfection, post-UV and post-chlorination. From each location, one submerged sampling box was retrieved after 1, 3, 6 and 12 months. Time series of biofilm samples recovered from various types of coupons from different locations were analyzed using physical and culture-based techniques for quantification of biofilms and detection of heterotrophic plate count (HPC) bacteria, Legionella, Mycobacterium, and sulfate reducing bacteria (SRB).
After one-year, galvanized steel had the highest concentration of HPC at 4.27 logs while copper had the lowest concentration of 3.08 logs of HPC. Bacterial growth data collected from the SRB tests was compiled to develop a numerical matrix using growth potential, biofilm formation potential and metal reduction potential of SRB isolates. This risk assessment matrix can be a useful tool for the water industry to evaluate the potential risk of MIC in their systems.
ContributorsNeal, Amber (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Alum, Absar (Committee member) / Arizona State University (Publisher)
Created2022
Description
Pathogens can proliferate in the built environment and can cause disease outbreaks if water and wastewater are not properly managed. Understanding pathogens that grow in engineered systems is crucial to protecting public health and preventing disease. Using dynamic computational models can reveal mechanistic insights into these systems to aid in understanding risk drivers and determining risk management strategies. The first research chapter of this thesis investigates tradeoffs for reducing the cost associated with Legionnaire’s Disease, hot water scalding, and energy use using a computational framework for evaluating an optimal water heater temperature set point. The model demonstrated that the optimal temperature set point was highly dependent on assumptions made regarding the dose response parameter for a common configuration of an electric water heater in a hospital setting. The optimal temperature was 55°C or 48°C for subclinical vs. clinical severity dose response, respectively, compared with current recommendations of 60°C to kill bacteria and 49°C to prevent scalding and conserve energy.
The second research chapter models the population dynamics of antibiotic-susceptible Escherichia coli (E. coli) and antibiotic-resistant E. coli with a population ecology-exposure assessment model in surface water to quantify the risk of urinary tract infection from recreational swimming activities. Horizontal gene transfer (HGT) was modeled in the environment and the human gastrointestinal tract for several scenarios. HGT was generally not a dominant driver of exposure estimates compared to other factors such as growth and dilution, however, the rank order of factors was scenario-dependent.
The final research chapter models pathogen transport from wastewater treatment plant (WWTP) exposures and assesses the risk to workers based on several exposure scenarios. Case studies were performed to investigate infection risk drivers across different scenarios, including adjustments for the timing of exposure and personal protective equipment. A web application was developed for use by WWTP risk managers to be used with site-specific data.
The proposed modeling frameworks identified risk drivers across several microbial risk scenarios and provide flexible tools for risk managers to use when making water treatment and use decisions for water management plans used for premise plumbing as well as for wastewater treatment practices.
ContributorsHeida, Ashley (Author) / Hamilton, Kerry (Thesis advisor) / Garcia, Margared (Committee member) / Muenich, Rebecca (Committee member) / Wilson, Amanda (Committee member) / Arizona State University (Publisher)
Created2023
Description
Energy can be harvested from wastewater using microbial fuel cells (MFC). In order to increase power generation, MFCs can be scaled-up. The MFCs are designed with two air cathodes and two anode electrodes. The limiting electrode for power generation is the cathode and in order to maximize power, the cathodes were made out of a C-N-Fe catalyst and a polytetrafluoroethylene binder which had a higher current production at -3.2 mA/cm2 than previous carbon felt cathodes at -0.15 mA/cm2 at a potential of -0.29 V. Commercial microbial fuel cells from Aquacycl were tested for their power production while operating with simulated blackwater achieved an average of 5.67 mW per cell. The small MFC with the C-N-Fe catalyst and one cathode was able to generate 8.7 mW. Imitating the Aquacycl cells, the new MFC was a scaled-up version of the small MFC where the cathode surface area increased from 81 cm2 to 200 cm2. While the MFC was operating with simulated blackwater, the peak power produced was 14.8 mW, more than the smaller MFC, but only increasing in the scaled-up MFC by 1.7 when the surface area of the cathode increased by 2.46. Further long-term application can be done, as well as operating multiple MFCs in series to generate more power and improve the design.
ContributorsRussell, Andrea (Author) / Torres, Cesar (Thesis advisor) / Garcia Segura, Sergio (Committee member) / Fraser, Matthew (Committee member) / Arizona State University (Publisher)
Created2022
Description
Microscopic algae have been investigated extensively by researchers for decades for their ability to bioremediate wastewater and flue gas while producing valuable biomass for use as feed, fuel, fertilizer, nutraceutical, and other specialty products. Reports of the exciting commercial potential of this diverse group of organisms started appearing in the literature as early as the 1940’s. However, nearly 80 years later, relatively few successful commercial microalgae installations exist and algae have not yet reached agricultural commodity status. This dissertation examines three major bottlenecks to commercial microalgae production including lack of an efficient and economical cultivation strategy, poor management of volatile waste nutrients, and costly harvesting and post processing strategies. A chapter is devoted to each of these three areas to gain a better understanding of each bottleneck as well as strategies for overcoming them.
The first chapter demonstrates the capability of two strains of Scenedesmus acutus to grow in ultra-high-density (>10 g L-1 dry weight biomass) cultures in flat panel photobioreactors for year-round production in the desert Southwest with record volumetric biomass productivity. The advantages and efficiency of high-density cultivation are discussed. The second chapter focuses on uptake and utilization of the volatile components of wastewater: ammonia and carbon dioxide. Scenedesmus acutus was cultured on wastewater from both municipal and agricultural origin and was shown to perform significantly better on flue gas as compared to commercial grade CO2 and just as well on waste nutrients as the commonly used BG-11 laboratory culture media, all while producing up to 50% lipids of the dry weight biomass suitable for use in biodiesel. The third chapter evaluates the feasibility of using gravity sedimentation for the harvesting of the difficult-to-separate Scenedesmus acutus green algae biomass followed by microfluidization to disrupt the cells. Lipid-extracted biomass was then studied as a fertilizer for plants and shown to have similar performance to a commercially available 4-6-6 fertilizer. Based on the work from these three chapters, a summary of modifications are suggested to help current and future microalgae companies be more competitive in the marketplace with traditional agricultural commodities.
The first chapter demonstrates the capability of two strains of Scenedesmus acutus to grow in ultra-high-density (>10 g L-1 dry weight biomass) cultures in flat panel photobioreactors for year-round production in the desert Southwest with record volumetric biomass productivity. The advantages and efficiency of high-density cultivation are discussed. The second chapter focuses on uptake and utilization of the volatile components of wastewater: ammonia and carbon dioxide. Scenedesmus acutus was cultured on wastewater from both municipal and agricultural origin and was shown to perform significantly better on flue gas as compared to commercial grade CO2 and just as well on waste nutrients as the commonly used BG-11 laboratory culture media, all while producing up to 50% lipids of the dry weight biomass suitable for use in biodiesel. The third chapter evaluates the feasibility of using gravity sedimentation for the harvesting of the difficult-to-separate Scenedesmus acutus green algae biomass followed by microfluidization to disrupt the cells. Lipid-extracted biomass was then studied as a fertilizer for plants and shown to have similar performance to a commercially available 4-6-6 fertilizer. Based on the work from these three chapters, a summary of modifications are suggested to help current and future microalgae companies be more competitive in the marketplace with traditional agricultural commodities.
ContributorsWray, Joshua (Author) / Dempster, Thomas (Thesis advisor) / Roberson, Robert (Thesis advisor) / Bingham, Scott (Committee member) / Neuer, Susanne (Committee member) / Arizona State University (Publisher)
Created2019
Description
Monitoring human exposure to chemicals posing public health threats is critically important for risk management and for informing regulatory actions. Chemical threats result from both environmental pollutants and elected substance use (e.g., consumption of drugs, alcohol and tobacco). Measuring chemical occurrence and concentrations in environmental matrices can help to pinpoint human exposure routes. For instance, indoor dust, a sink of indoor environmental contaminants, can serve to assess indoor air contamination and associated human exposures. Urban wastewater arriving at treatment plants contains urine and stool from the general population, the analysis of which can provide information on chemical threats in the community and ongoing harmful exposures. Analysis of sewage sludge can serve to reveal the identity and quantity of persistent organic pollutants in cities and inform estimates of toxic body burdens in local populations.
The objective of this dissertation was to investigate the occurrence and quantity of select, potentially harmful, anthropogenic chemicals in various environmental matrices and to explore the diagnostic value of analytical assays for informing public health decision-making. This dissertation (i) is the first to report spatio-temporal variations and estrogenic burdens of five parabens in sewage sludge from at the U.S. nationwide scale; (ii) represents the first China-wide survey to assess the occurrence and toxic emissions of parabens, triclosan, triclocarban, as well as triclocarban metabolites and transformation products contained in Chinese sewage sludge; (iii) documents the first use of a dispersive solid phase extraction method for indoor dust to measure dust-borne parabens, triclosan and triclocarban and estimating associated human exposures from dust ingestion; and (iv) is the first U.S. study to assess population-level alcohol and nicotine consumption in three U.S. communities using wastewater-based epidemiology (WBE). Obtained data on baseline levels of selected emerging contaminants in sewage sludge and indoor dust can serve to inform the future monitoring needs, risk assessment, and policy making. This work showcases the utility of WBE and urban metabolism metrology via dust and sewage sludge analysis to assess human behavior (e.g., drinking and smoking) and exposure risks more rapidly, efficiently and anonymously than traditional approaches can.
The objective of this dissertation was to investigate the occurrence and quantity of select, potentially harmful, anthropogenic chemicals in various environmental matrices and to explore the diagnostic value of analytical assays for informing public health decision-making. This dissertation (i) is the first to report spatio-temporal variations and estrogenic burdens of five parabens in sewage sludge from at the U.S. nationwide scale; (ii) represents the first China-wide survey to assess the occurrence and toxic emissions of parabens, triclosan, triclocarban, as well as triclocarban metabolites and transformation products contained in Chinese sewage sludge; (iii) documents the first use of a dispersive solid phase extraction method for indoor dust to measure dust-borne parabens, triclosan and triclocarban and estimating associated human exposures from dust ingestion; and (iv) is the first U.S. study to assess population-level alcohol and nicotine consumption in three U.S. communities using wastewater-based epidemiology (WBE). Obtained data on baseline levels of selected emerging contaminants in sewage sludge and indoor dust can serve to inform the future monitoring needs, risk assessment, and policy making. This work showcases the utility of WBE and urban metabolism metrology via dust and sewage sludge analysis to assess human behavior (e.g., drinking and smoking) and exposure risks more rapidly, efficiently and anonymously than traditional approaches can.
ContributorsChen, Jing (Author) / Halden, Rolf U. (Thesis advisor) / Borges, Chad R (Committee member) / Abbaszadegan, Morteza (Committee member) / Arizona State University (Publisher)
Created2018
Description
There is much at stake with the smart city. This urban governance movement is
predicated on infusing information-and-communication technology into nearly all aspects of the built environment, while at the same time transforming how cities are planned and managed. The smart city movement is global in scale with initiatives being rolled out all over the planet, driven by proponents with deep pockets of wealth and influence, and a lucrative opportunity with market projections in the billions or trillions of dollars (over the next five to ten years). However, the smart city label can be nebulous and amorphous, seemingly subsuming unrelated technologies, practices, and policies as necessary. Yet, even with this ambiguity, or perhaps because of it, the smart city vision is still able to colonize urban landscapes and capture the political imaginations of decision makers. In order to know just what the smart city entails I work to bring analytic clarity to the actions, visions, and values of this movement.
In short, the arc of this project moves from diving into the "smart city" discourses; to picking apart the ideologies at its heart; to engaging with the dual logics—control and accumulation—that drive the smart city; and finally to imagining what an alternative techno- politics might look like and how we might achieve it. My goal is that by analyzing the techno- politics of the smart city we will be better equipped to understand these urban transformations— what logics drive them, what they herald, and what our role should be in how they develop.
ContributorsSadowski, Jathan (Author) / Guston, David H. (Thesis advisor) / Finn, Edward (Committee member) / Miller, Thaddeus R. (Committee member) / Arizona State University (Publisher)
Created2016