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- All Subjects: Environmental engineering
- All Subjects: Sustainability
- Creators: Halden, Rolf
- Member of: ASU Electronic Theses and Dissertations
Description
Nitrate is the most prevalent water pollutant limiting the use of groundwater as a potable water source. The overarching goal of this dissertation was to leverage advances in nanotechnology to improve nitrate photocatalysis and transition treatment to the full-scale. The research objectives were to (1) examine commercial and synthesized photocatalysts, (2) determine the effect of water quality parameters (e.g., pH), (3) conduct responsible engineering by ensuring detection methods were in place for novel materials, and (4) develop a conceptual framework for designing nitrate-specific photocatalysts. The key issues for implementing photocatalysis for nitrate drinking water treatment were efficient nitrate removal at neutral pH and by-product selectivity toward nitrogen gases, rather than by-products that pose a human health concern (e.g., nitrite). Photocatalytic nitrate reduction was found to follow a series of proton-coupled electron transfers. The nitrate reduction rate was limited by the electron-hole recombination rate, and the addition of an electron donor (e.g., formate) was necessary to reduce the recombination rate and achieve efficient nitrate removal. Nano-sized photocatalysts with high surface areas mitigated the negative effects of competing aqueous anions. The key water quality parameter impacting by-product selectivity was pH. For pH < 4, the by-product selectivity was mostly N-gas with some NH4+, but this shifted to NO2- above pH = 4, which suggests the need for proton localization to move beyond NO2-. Co-catalysts that form a Schottky barrier, allowing for localization of electrons, were best for nitrate reduction. Silver was optimal in heterogeneous systems because of its ability to improve nitrate reduction activity and N-gas by-product selectivity, and graphene was optimal in two-electrode systems because of its ability to shuttle electrons to the working electrode. "Environmentally responsible use of nanomaterials" is to ensure that detection methods are in place for the nanomaterials tested. While methods exist for the metals and metal oxides examined, there are currently none for carbon nanotubes (CNTs) and graphene. Acknowledging that risk assessment encompasses dose-response and exposure, new analytical methods were developed for extracting and detecting CNTs and graphene in complex organic environmental (e.g., urban air) and biological matrices (e.g. rat lungs).
ContributorsDoudrick, Kyle (Author) / Westerhoff, Paul (Thesis advisor) / Halden, Rolf (Committee member) / Hristovski, Kiril (Committee member) / Arizona State University (Publisher)
Created2013
Description
In the past three decades alone, the United States has witnessed a dramatic rise in the prevalence of obesity and overweight in adults and children. Efforts towards obesity mitigation and prevention have produced promising recommendations and researchers and practitioners alike acknowledge that real solutions must match the complexity of the problem. Comprehensive approaches that target environmental, economic, socio-cultural, and knowledge-based factors that influence diet and physical activity are highly recommended. However, the literature yields little in the way of what such comprehensive obesity interventions actually entail and how they ought to be developed. In particular, there are knowledge gaps in how various stakeholder groups can bridge institutional barriers to collaborate in ways that maximize resources, build upon synergies, and avoid duplication of efforts; and how specific recommendations are actually implemented. This thesis aims to contribute to an emerging body of literature that fills this gap by presenting a practical case study on how to create a playground obesity intervention in the Gateway District of Phoenix, Arizona, in collaboration with researchers, health professionals, neighborhood residents, and city officials. The objectives were two-fold: 1. To outline concrete steps that will allow an organization to create a playground linked with healthy kids education program that aims to increase physical activity, perceptions of safety, and community cohesion; 2. To outline how diverse stakeholders can collaborate effectively to create such a cohesive, complex obesity intervention. A detailed, actionable intervention manual was drafted through semi-structured interviews, literature review, a survey, a stakeholder workshop, and an extended peer-review. The manual describes the sequence of actions necessary for creating an innovative playground that reinforces learning, encourages creative play, and increases physical activity. The sequence of actions was linked with existing local assets, stakeholder roles and responsibilities, costs, and potential barriers. This manual, as well as the process itself, can serve as a transferable model for helping organizations come together to build the capacity required in order to tackle complex health challenges.
ContributorsXiong, Angela (Author) / Wiek, Arnim (Thesis advisor) / Golub, Aaron (Committee member) / Otu, Essen (Committee member) / Arizona State University (Publisher)
Created2013
Description
Over the last two decades programs and mandates to encourage and foster sustainable urban development have arisen throughout the world, as cities have emerged as key opportunity sites for sustainable development due to the compactness and localization of services and resources. In order to recognize this potential, scholars and practitioners have turned to the practice of visioning as a way to motivate actions and decision making toward a sustainable future. A "vision" is defined as desirable state in the future and scholars believe that the creation of a shared, motivational vision is the best starting point to catalyze positive and sustainable change. However, recent studies on city visions indicate that they do not offer substantive sustainability content, and methods or processes to evaluate the sustainability content of the resulting vision (sustainability appraisal or assessment) are often absent from the visioning process. Thus, this paper explores methods for sustainability appraisal and their potential contributions to (and in) visioning. The goal is to uncover the elements of a robust sustainability appraisal and integrate them into the visioning process. I propose an integrated sustainability appraisal procedure based on sustainability criteria, indicators, and targets as part of a visioning methodology that was developed by a team of researchers at Arizona State University (ASU) of which I was a part. I demonstrate the applicability of the appraisal method in a case study of visioning in Phoenix, Arizona. The proposed method allows for early and frequent consideration and evaluation of sustainability objectives for urban development throughout the visioning process and will result in more sustainability-oriented visions. Further, it can allow for better measurement and monitoring of progress towards sustainability goals, which can make the goals more tangible and lead to more accountability for making progress towards the development of more sustainable cities in the future.
ContributorsMinowitz, Amy (Author) / Wiek, Arnim (Thesis advisor) / Golub, Aaron (Committee member) / Pfeiffer, Deirdre (Committee member) / Arizona State University (Publisher)
Created2013
Description
A methodology is developed that integrates institutional analysis with Life Cycle Assessment (LCA) to identify and overcome barriers to sustainability transitions and to bridge the gap between environmental practitioners and decisionmakers. LCA results are rarely joined with analyses of the social systems that control or influence decisionmaking and policies. As a result, LCA conclusions generally lack information about who or what controls different parts of the system, where and when the processes' environmental decisionmaking happens, and what aspects of the system (i.e. a policy or regulatory requirement) would have to change to enable lower environmental impact futures. The value of the combined institutional analysis and LCA (the IA-LCA) is demonstrated using a case study of passenger transportation in the Phoenix, Arizona metropolitan area. A retrospective LCA is developed to estimate how roadway investment has enabled personal vehicle travel and its associated energy, environmental, and economic effects. Using regional travel forecasts, a prospective life cycle inventory is developed. Alternative trajectories are modeled to reveal future "savings" from reduced roadway construction and vehicle travel. An institutional analysis matches the LCA results with the specific institutions, players, and policies that should be targeted to enable transitions to these alternative futures. The results show that energy, economic, and environmental benefits from changes in passenger transportation systems are possible, but vary significantly depending on the timing of the interventions. Transition strategies aimed at the most optimistic benefits should include 1) significant land-use planning initiatives at the local and regional level to incentivize transit-oriented development infill and urban densification, 2) changes to state or federal gasoline taxes, 3) enacting a price on carbon, and 4) nearly doubling vehicle fuel efficiency together with greater market penetration of alternative fuel vehicles. This aggressive trajectory could decrease the 2050 energy consumption to 1995 levels, greenhouse gas emissions to 1995, particulate emissions to 2006, and smog-forming emissions to 1972. The potential benefits and costs are both private and public, and the results vary when transition strategies are applied in different spatial and temporal patterns.
ContributorsKimball, Mindy (Author) / Chester, Mikhail (Thesis advisor) / Allenby, Braden (Committee member) / Golub, Aaron (Committee member) / Arizona State University (Publisher)
Created2014
Description
Contaminants of emerging concern (CECs) present in wastewater effluent can threat its safe discharge or reuse. Additional barriers of protection can be provided using advanced or natural treatment processes. This dissertation evaluated ozonation and constructed wetlands to remove CECs from wastewater effluent. Organic CECs can be removed by hydroxyl radical formed during ozonation, however estimating the ozone demand of wastewater effluent is complicated due to the presence of reduced inorganic species. A method was developed to estimate ozone consumption only by dissolved organic compounds and predict trace organic oxidation across multiple wastewater sources. Organic and engineered nanomaterial (ENM) CEC removal in constructed wetlands was investigated using batch experiments and continuous-flow microcosms containing decaying wetland plants. CEC removal varied depending on their physico-chemical properties, hydraulic residence time (HRT) and relative quantities of plant materials in the microcosms. At comparable HRTs, ENM removal improved with higher quantity of plant materials due to enhanced sorption which was verified in batch-scale studies with plant materials. A fate-predictive model was developed to evaluate the role of design loading rates on organic CEC removal. Areal removal rates increased with hydraulic loading rates (HLRs) and carbon loading rates (CLRs) unless photolysis was the dominant removal mechanism (e.g. atrazine). To optimize CEC removal, wetlands with different CLRs can be used in combination without lowering the net HLR. Organic CEC removal in denitrifying conditions of constructed wetlands was investigated and selected CECs (e.g. estradiol) were found to biotransform while denitrification occurred. Although level of denitrification was affected by HRT, similar impact on estradiol was not observed due to a dominant effect from plant biomass quantity. Overall, both modeling and experimental findings suggest considering CLR as an equally important factor with HRT or HLR to design constructed wetlands for CEC removal. This dissertation provided directions to select design parameters for ozonation (ozone dose) and constructed wetlands (design loading rates) to meet organic CEC removal goals. Future research is needed to understand fate of ENMs during ozonation and quantify the contributions from different transformation mechanisms occurring in the wetlands to incorporate in a model and evaluate the effect of wetland design.
ContributorsSharif, Fariya (Author) / Westerhoff, Paul (Thesis advisor) / Halden, Rolf (Committee member) / Fox, Peter (Committee member) / Herckes, Pierre (Committee member) / Arizona State University (Publisher)
Created2013
Description
The influence of climate variability and reclaimed wastewater on the water supply necessitates improved understanding of the treatability of trace and bulk organic matter. Dissolved organic matter (DOM) mobilized during extreme weather events and in treated wastewater includes natural organic matter (NOM), contaminants of emerging concern (CECs), and microbial extracellular polymeric substances (EPS). The goal of my dissertation was to quantify the impacts of extreme weather events on DOM in surface water and downstream treatment processes, and to improve membrane filtration efficiency and CECs oxidation efficiency during water reclamation with ozone. Surface water quality, air quality and hydrologic flow rate data were used to quantify changes in DOM and turbidity following dust storms, flooding, or runoff from wildfire burn areas in central Arizona. The subsequent impacts to treatment processes and public perception of water quality were also discussed. Findings showed a correlation between dust storm events and change in surface water turbidity (R2=0.6), attenuation of increased DOM through reservoir systems, a 30-40% increase in organic carbon and a 120-600% increase in turbidity following severe flooding, and differing impacts of upland and lowland wildfires. The use of ozone to reduce membrane fouling caused by vesicles (a subcomponent of EPS) and oxidize CECs through increased hydroxyl radical (HO●) production was investigated. An "ozone dose threshold" was observed above which addition of hydrogen peroxide increased HO● production; indicating the presence of ambient promoters in wastewater. Ozonation of CECs in secondary effluent over titanium dioxide or activated carbon did not increase radial production. Vesicles fouled ultrafiltration membranes faster (20 times greater flux decline) than polysaccharides, fatty acids, or NOM. Based upon the estimated carbon distribution of secondary effluent, vesicles could be responsible for 20-60% of fouling during ultrafiltration and may play a vital role in other environmental processes as well. Ozone reduced vesicle-caused membrane fouling that, in conjunction with the presence of ambient promoters, helps to explain why low ozone dosages improve membrane flux during full-scale water reclamation.
ContributorsBarry, Michelle (Author) / Barry, Michelle C (Thesis advisor) / Westerhoff, Paul (Committee member) / Fox, Peter (Committee member) / Halden, Rolf (Committee member) / Hristovski, Kiril (Committee member) / Arizona State University (Publisher)
Created2014
Description
Arsenic (As) and chromium (Cr) occur naturally in AZ surface and groundwaters, pose different health impacts, and exhibit different treatment efficacies. Hexavalent chromium (Cr(VI)) has newly recognized human health concerns, and State and Federal agencies are evaluating a low Cr(VI)-specific maximum contaminant level (MCL) for drinking water. Occurrence of Cr and As in municipal drinking waters and industrial cooling tower waters was quantified by grab samples and compared with sampling results obtained from a new passive sampler developed specifically for Cr(VI). Cr(VI) and As concentrations in groundwater used for cooling tower make-up water concentrations were ~3 ppb and ~4 ppb, respectively, and were concentrated significantly in blowdown water (~20 ppb and ~40 ppb). Based upon pending Cr(VI), As, and other metal regulations, these blowdown waters will need routine monitoring and treatment. Cr(VI) concentrations in a water treatment plant (WTP) raw and finished water samples varied from 0.5 and 2 ppb for grab samples collected every 4 hours for 7 consecutive days using an ISCO sampler. The development of an ion exchange (IX) based passive sampler was validated in the field at the WTP and yielded an average exposure within 1 standard deviation of ISCO sampler grab data. Sampling at both the WTP and cooling towers suggested sources of Cr(III) from treatment chemicals or wood preservatives may exist. Since both facilities use chlorine oxidants, I quantified the apparent (pH=5) second-order rate constant for aqueous chlorine (HOCl/OCl-) with Cr(III) to form Cr(VI) as 0.7 M-1s-1. Under typical conditions (2 ppb Cr(III) ; 2 mg/L Cl2) the half-life for the conversion of Cr(III) to the more toxic form Cr(VI) is 4.7 hours. The occurrence studies in AZ and CA show the Cr(VI) and As treatment of groundwaters will be required to meet stringent Cr(VI) regulations. IX technologies, both strong base anion (SBA) and weak base anion (WBA) resin types were screened (and compared) for Cr removal. The SBA IX process for As removal was optimized by utilizing a reactive iron coagulation and filtration (RCF) process to treat spent IX brine, which was then reused to for SBA resin regeneration.
ContributorsBowen, Alexandra (Author) / Paul, Westerhoff K. (Thesis advisor) / Hristovski, Kiril (Committee member) / Halden, Rolf (Committee member) / Arizona State University (Publisher)
Created2014
Description
Beneficiary participation has become popular in international development generally, and it is an essential feature of sustainable development. But there are diverse definitions of and motivations for using beneficiary participation, and empirical literature on its effects is underdeveloped. This dissertation aims to clarify what beneficiary participation is and whether there is empirical support for claims about its benefits.
I review historical trends in international development that led to the popularity of both sustainable development and beneficiary participation. This review identifies central themes in defining beneficiary participation and motivations for using it.
I also developed a new typology of beneficiary participation based on a literature review of how scholars define beneficiary participation. I found that the main dimensions of beneficiary participation are (1) participants, (2) channels, (3) types of inputs, (4) timing, and (5) goals. By making these dimensions explicit, this work helps researchers and development practitioners more clearly describe the types of beneficiary participation they study, employ, and advocate for.
To contribute to empirical literature about beneficiary participation, I conducted a case-study of two urban development projects in Bhopal, India. I collected data with a structured survey of project beneficiaries in four slums (two slums from each project) and semi-structured interviews with each project's organizers. And project documents provided secondary data on both projects. The results indicate that local elites did not capture a disproportionate share of either project's benefits, at least with respect to individual household toilets. Because project organizers rather than beneficiaries selected households that would receive toilets, both cases serve as counterexamples to the claim that beneficiaries must intensely participate for projects' benefits to be distributed equitably.
Finally, I review academic literature for empirical evidence that supports claims about the advantages of beneficiary participation. There is relatively strong empirical support for the claim that beneficiary participation improves project outcomes, but empirical support for most other claims (i.e., that it helps make projects more efficient, distribute benefits equitably, and sustain project benefits) is weak. And empirical research suggests that one claimed benefit, empowerment, rarely materializes. In general, more empirical research about beneficiary participation is needed.
I review historical trends in international development that led to the popularity of both sustainable development and beneficiary participation. This review identifies central themes in defining beneficiary participation and motivations for using it.
I also developed a new typology of beneficiary participation based on a literature review of how scholars define beneficiary participation. I found that the main dimensions of beneficiary participation are (1) participants, (2) channels, (3) types of inputs, (4) timing, and (5) goals. By making these dimensions explicit, this work helps researchers and development practitioners more clearly describe the types of beneficiary participation they study, employ, and advocate for.
To contribute to empirical literature about beneficiary participation, I conducted a case-study of two urban development projects in Bhopal, India. I collected data with a structured survey of project beneficiaries in four slums (two slums from each project) and semi-structured interviews with each project's organizers. And project documents provided secondary data on both projects. The results indicate that local elites did not capture a disproportionate share of either project's benefits, at least with respect to individual household toilets. Because project organizers rather than beneficiaries selected households that would receive toilets, both cases serve as counterexamples to the claim that beneficiaries must intensely participate for projects' benefits to be distributed equitably.
Finally, I review academic literature for empirical evidence that supports claims about the advantages of beneficiary participation. There is relatively strong empirical support for the claim that beneficiary participation improves project outcomes, but empirical support for most other claims (i.e., that it helps make projects more efficient, distribute benefits equitably, and sustain project benefits) is weak. And empirical research suggests that one claimed benefit, empowerment, rarely materializes. In general, more empirical research about beneficiary participation is needed.
ContributorsKutter, Robert W (Author) / Aggarwal, Rimjhim (Thesis advisor) / Golub, Aaron (Committee member) / Wiek, Arnim (Committee member) / Arizona State University (Publisher)
Created2014
Description
The conflict conditions that afflict the livelihoods of Palestinian residents living in the West Bank are embedded within the population's ability to travel more so than any other routine activity. For Palestinian residents, domestic and international travel is a process of following paths riddled with multiple barriers that are both physical and political. Past studies have done well to paint a clear picture of the harsh transportation landscape in the region. However, less attention has focused on how barriers interact to indirectly and directly affect levels of accessibility and well-being. Additionally, suggested development solutions are rarely capable of being successfully implemented given current political conditions. This dissertation uses a systems approach to understand drivers of accessibility challenges in the West Bank and uses the understanding to propose a method to identify transition strategies that may be presently initiated whilst maintaining the ability to provide adequate benefit. The research question informing the study asks, How do drivers influencing the issue of poor accessibility and well-being in the West Bank persist and interact, and how might solutions be approached? The dissertation approaches the question in four sequential actions that each produces a functional planning deliverable. First, a system map that depicts the drivers and influences to the problem of poor accessibility and well-being is constructed (Chapter 4). Second, a future vision for the transportation system in the West Bank is identified (Chapter 5). Third, the system map and vision are used to assess how conflict conditions affect transition research (Chapter 6). Finally, the previous three deliverables are used to suggest a guide for transition management for transportation development in the West Bank (Chapter 7). Combinations of four different data sets, including an extensive review of published literature, field observations, individual field expert interviews, and group commuter interviews inform the research. Additionally, the Transformational Sustainability Research framework provides a normative base for the steps taken throughout the research. Ultimately, the dissertation presents an interpretation of information that has theoretical and practical application potential in transformational sustainability research and development efforts in the region respectively.
ContributorsAhmad, Omaya Heidi (Author) / Golub, Aaron (Thesis advisor) / Aggarwal, Rimjhim (Committee member) / Saleh Sadaqa, Ahmad (Committee member) / Arizona State University (Publisher)
Created2015
Description
Targeted growth is necessary for sustainable urbanization. There is a pattern in China of rapid development due to inflated projections. This creates "ghost towns" and underutilized urban services that don't support the population.
In the case of Taiyuan, this industrial third-tier city of 4.2 million people. A majority of the newer residential services and high-end commercial areas are on the older, eastern side of the city. Since 2007, major urban investments have been made in developing the corridor that leads to the airport, including building a massive hospital, a new sports stadium, and "University City". The intention of the city officials is to encourage a new image of Taiyuan- one that is a tourist destination, one that has a high standard of living for residents. However, the consequences of these major developments might be immense, because of the required shift of community, residents and capital that would be required to sustain these new areas. Much of the new development lacks the reliable and frequent public transit of the more established downtown areas.
Do these investments in medical complexes, sports stadiums and massive shopping centers create new jobs that impact the income disparity, or do these new areas take years to fill, creating vacuums of investment that remove funding from areas with established communities? Can Taiyuan move successfully to a post-industrial economy with these government interventions, or is it too much too soon?
By examining demographic data from 2000, 2007, 2009, 2011, and 2013, research on sustainability assessments in Chinese cities (Lu Jia), and translated government publications detailing the urbanization efforts in Taiyuan, I will assess the results of the urbanization changes instituted by the new mayor, Geng Yanbo. My thesis will evaluate the success and failures of these policies and the implications for Taiyuan.
In the case of Taiyuan, this industrial third-tier city of 4.2 million people. A majority of the newer residential services and high-end commercial areas are on the older, eastern side of the city. Since 2007, major urban investments have been made in developing the corridor that leads to the airport, including building a massive hospital, a new sports stadium, and "University City". The intention of the city officials is to encourage a new image of Taiyuan- one that is a tourist destination, one that has a high standard of living for residents. However, the consequences of these major developments might be immense, because of the required shift of community, residents and capital that would be required to sustain these new areas. Much of the new development lacks the reliable and frequent public transit of the more established downtown areas.
Do these investments in medical complexes, sports stadiums and massive shopping centers create new jobs that impact the income disparity, or do these new areas take years to fill, creating vacuums of investment that remove funding from areas with established communities? Can Taiyuan move successfully to a post-industrial economy with these government interventions, or is it too much too soon?
By examining demographic data from 2000, 2007, 2009, 2011, and 2013, research on sustainability assessments in Chinese cities (Lu Jia), and translated government publications detailing the urbanization efforts in Taiyuan, I will assess the results of the urbanization changes instituted by the new mayor, Geng Yanbo. My thesis will evaluate the success and failures of these policies and the implications for Taiyuan.
ContributorsDolins, Sarah-Laura (Author) / Webster, Douglas (Thesis advisor) / Golub, Aaron (Committee member) / Cai, Jianming (Committee member) / Arizona State University (Publisher)
Created2014