Matching Items (45)
Description
This document builds a model, the Resilience Engine, of how a given sociotechnical innovation contributes to the resilience of its society, where the failure points of that process might be, and what outcomes, resilient or entropic, can be generated by the uptake of a particular innovation. Closed systems, which tend towards stagnation and collapse, are distinguished from open systems, which through ongoing encounters with external novelty, tend towards enduring resilience. Heterotopia, a space bounded from the dominant order in which novelty is generated and defended, is put forth as the locus of innovation for systemic resilience, defined as the capacity to adapt to environmental changes. The generative aspect of the Resilience Engine lies in a dialectic between a heterotopia and the dominant system across a membrane which permits interaction while maintaining the autonomy of the new space. With a model of how innovation, taken up by agents seeking power outside the dominant order, leads to resilience, and of what generates failures of the Resilience Engine as well as successes, the model is tested against cases drawn from two key virtual worlds of the mid-2000s. The cases presented largely validate the model, but generate a crucial surprise. Within those worlds, 2008-2010 saw an abrupt cultural transformation as the dialectic stage of the Resilience Engine's operation generated victories for the dominant order over promising emergent attributes of virtual heterotopia. At least one emergent practice has been assimilated, generating systemic resilience, that of the conference backchannel. A surprise, however, comes from extensive evidence that one element never problematized in thinking about innovation, the discontent agent, was largely absent from virtual worlds. Rather, what users sought was not greater agency but the comfort of submission over the burdens of self-governance. Thus, aside from minor cases, the outcome of the operation of the Resilience Engine within the virtual worlds studied was the colonization of the heterotopic space for the metropolis along with attempts by agents both external and internal to generate maximum order. Pursuant to the Resilience Engine model, this outcome is a recipe for entropic collapse and for preventing new heterotopias from arising under the current dominant means of production.
ContributorsMcKnight, John Carter (Author) / Miller, Clark (Thesis advisor) / Hayes, Elisabeth (Committee member) / Allenby, Braden (Committee member) / Daer, Alice (Committee member) / Arizona State University (Publisher)
Created2013
Description
The United Nation's Framework Convention on Climate Change (UNFCCC) recognizes development as a priority for carbon dioxide (CO2) allocation, under its principle of "common but differentiated responsibilities". This was codified in the Kyoto Protocol, which exempt developing nations from binding emission reduction targets. Additionally, they could be the recipients of financed sustainable development projects in exchange for emission reduction credits that the developed nations could use to comply with emission targets. Due to ineffective results, post-Kyoto policy discussions indicate a transition towards mitigation commitments from major developed and developing emitters, likely supplemented by market-based mechanisms to reduce mitigation costs. Although the likelihood of achieving substantial emission reductions is increased by the new plan, there is a paucity of consideration to how an ethic of development might be advanced. Therefore, this research empirically investigates the role that CO2 plays in advancing human development (in terms of the Human Development Index or HDI) over the 1990 to 2010 time period. Based on empirical evidence, a theoretical CO2-development framework is established, which provides a basis for designing a novel policy proposal that integrates mitigation efforts with human development objectives. Empirical evidence confirms that CO2 and HDI are highly correlated, but that there are diminishing returns to HDI as per capita CO2 emissions increase. An examination of development pathways reveals that as nations develop, their trajectories generally become less coupled with CO2. Moreover, the developing countries with the greatest gains in HDI are also nations that have, or are in the process of moving toward, outward-oriented trade policies that involve increased domestic capabilities for product manufacture and export. With these findings in mind, future emission targets should reduce current emissions in developed nations and allow room for HDI growth in developing countries as well as in the least developed nations of the world. Emission trading should also be limited to nations with similar HDI levels to protect less-developed nations from unfair competition for capacity building resources. Lastly, developed countries should be incentivized to invest in joint production ventures within the LDCs to build capacity for self-reliant and sustainable development over the long-term.
ContributorsClark, Susan Spierre (Author) / Seager, Thomas P. (Thesis advisor) / Allenby, Braden (Committee member) / Klinsky, Sonja (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation explores the use of bench-scale batch microcosms in remedial design of contaminated aquifers, presents an alternative methodology for conducting such treatability studies, and - from technical, economical, and social perspectives - examines real-world application of this new technology. In situ bioremediation (ISB) is an effective remedial approach for many contaminated groundwater sites. However, site-specific variability necessitates the performance of small-scale treatability studies prior to full-scale implementation. The most common methodology is the batch microcosm, whose potential limitations and suitable technical alternatives are explored in this thesis. In a critical literature review, I discuss how continuous-flow conditions stimulate microbial attachment and biofilm formation, and identify unique microbiological phenomena largely absent in batch bottles, yet potentially relevant to contaminant fate. Following up on this theoretical evaluation, I experimentally produce pyrosequencing data and perform beta diversity analysis to demonstrate that batch and continuous-flow (column) microcosms foster distinctly different microbial communities. Next, I introduce the In Situ Microcosm Array (ISMA), which took approximately two years to design, develop, build and iteratively improve. The ISMA can be deployed down-hole in groundwater monitoring wells of contaminated aquifers for the purpose of autonomously conducting multiple parallel continuous-flow treatability experiments. The ISMA stores all sample generated in the course of each experiment, thereby preventing the release of chemicals into the environment. Detailed results are presented from an ISMA demonstration evaluating ISB for the treatment of hexavalent chromium and trichloroethene. In a technical and economical comparison to batch microcosms, I demonstrate the ISMA is both effective in informing remedial design decisions and cost-competitive. Finally, I report on a participatory technology assessment (pTA) workshop attended by diverse stakeholders of the Phoenix 52nd Street Superfund Site evaluating the ISMA's ability for addressing a real-world problem. In addition to receiving valuable feedback on perceived ISMA limitations, I conclude from the workshop that pTA can facilitate mutual learning even among entrenched stakeholders. In summary, my doctoral research (i) pinpointed limitations of current remedial design approaches, (ii) produced a novel alternative approach, and (iii) demonstrated the technical, economical and social value of this novel remedial design tool, i.e., the In Situ Microcosm Array technology.
ContributorsKalinowski, Tomasz (Author) / Halden, Rolf U. (Thesis advisor) / Johnson, Paul C (Committee member) / Krajmalnik-Brown, Rosa (Committee member) / Bennett, Ira (Committee member) / Arizona State University (Publisher)
Created2013
Description
Reductive dechlorination by members of the bacterial genus Dehalococcoides is a common and cost-effective avenue for in situ bioremediation of sites contaminated with the chlorinated solvents, trichloroethene (TCE) and perchloroethene (PCE). The overarching goal of my research was to address some of the challenges associated with bioremediation timeframes by improving the rates of reductive dechlorination and the growth of Dehalococcoides in mixed communities. Biostimulation of contaminated sites or microcosms with electron donor fails to consistently promote dechlorination of PCE/TCE beyond cis-dichloroethene (cis-DCE), even when the presence of Dehalococcoides is confirmed. Supported by data from microcosm experiments, I showed that the stalling at cis-DCE is due a H2 competition in which components of the soil or sediment serve as electron acceptors for competing microorganisms. However, once competition was minimized by providing selective enrichment techniques, I illustrated how to obtain both fast rates and high-density Dehalococcoides using three distinct enrichment cultures. Having achieved a heightened awareness of the fierce competition for electron donor, I then identified bicarbonate (HCO3-) as a potential H2 sink for reductive dechlorination. HCO3- is the natural buffer in groundwater but also the electron acceptor for hydrogenotrophic methanogens and homoacetogens, two microbial groups commonly encountered with Dehalococcoides. By testing a range of concentrations in batch experiments, I showed that methanogens are favored at low HCO3 and homoacetogens at high HCO3-. The high HCO3- concentrations increased the H2 demand which negatively affected the rates and extent of dechlorination. By applying the gained knowledge on microbial community management, I ran the first successful continuous stirred-tank reactor (CSTR) at a 3-d hydraulic retention time for cultivation of dechlorinating cultures. I demonstrated that using carefully selected conditions in a CSTR, cultivation of Dehalococcoides at short retention times is feasible, resulting in robust cultures capable of fast dechlorination. Lastly, I provide a systematic insight into the effect of high ammonia on communities involved in dechlorination of chloroethenes. This work documents the potential use of landfill leachate as a substrate for dechlorination and an increased tolerance of Dehalococcoides to high ammonia concentrations (2 g L-1 NH4+-N) without loss of the ability to dechlorinate TCE to ethene.
ContributorsDelgado, Anca Georgiana (Author) / Krajmalnik-Brown, Rosa (Thesis advisor) / Cadillo-Quiroz, Hinsby (Committee member) / Halden, Rolf U. (Committee member) / Rittmann, Bruce E. (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2013
Description
Many manmade chemicals used in consumer products are ultimately washed down the drain and are collected in municipal sewers. Efficient chemical monitoring at wastewater treatment (WWT) plants thus may provide up-to-date information on chemical usage rates for epidemiological assessments. The objective of the present study was to extrapolate this concept, termed 'sewage epidemiology', to include municipal sewage sludge (MSS) in identifying and prioritizing contaminants of emerging concern (CECs). To test this the following specific aims were defined: i) to screen and identify CECs in nationally representative samples of MSS and to provide nationwide inventories of CECs in U.S. MSS; ii) to investigate the fate and persistence in MSS-amended soils, of sludge-borne hydrophobic CECs; and iii) to develop an analytical tool relying on contaminant levels in MSS as an indicator for identifying and prioritizing hydrophobic CECs. Chemicals that are primarily discharged to the sewage systems (alkylphenol surfactants) and widespread persistent organohalogen pollutants (perfluorochemicals and brominated flame retardants) were analyzed in nationally representative MSS samples. A meta-analysis showed that CECs contribute about 0.04-0.15% to the total dry mass of MSS, a mass equivalent of 2,700-7,900 metric tonnes of chemicals annually. An analysis of archived mesocoms from a sludge weathering study showed that 64 CECs persisted in MSS/soil mixtures over the course of the experiment, with half-lives ranging between 224 and >990 days; these results suggest an inherent persistence of CECs that accumulate in MSS. A comparison of the spectrum of chemicals (n=52) analyzed in nationally representative biological specimens from humans and MSS revealed 70% overlap. This observed co-occurrence of contaminants in both matrices suggests that MSS may serve as an indicator for ongoing human exposures and body burdens of pollutants in humans. In conclusion, I posit that this novel approach in sewage epidemiology may serve to pre-screen and prioritize the several thousands of known or suspected CECs to identify those that are most prone to pose a risk to human health and the environment.
ContributorsVenkatesan, Arjunkrishna (Author) / Halden, Rolf U. (Thesis advisor) / Westerhoff, Paul (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2013
Description
DehaloR^2 is a previously characterized, trichloroethene (TCE)-dechlorinating culture and contains bacteria from the known dechlorinating genus, Dehalococcoides. DehaloR^2 was exposed to three anthropogenic contaminants, Triclocarban (TCC), tris(2-chloroethyl) phosphate (TCEP), and 1,1,1-trichloroethane (TCA) and two biogenic-like halogenated compounds, 2,6-dibromophenol (2,6-DBP) and 2,6-dichlorophenol (2,6-DCP). The effects on TCE dechlorination ability due to 2,6-DBP and 2,6-DCP exposures were also investigated. DehaloR^2 did not dechlorinate TCC or TCEP. After initial exposure to TCA, half of the initial TCA was dechlorinated to 1,1-dichloroethane (DCA), however half of the TCA remained by day 100. Subsequent TCA and TCE re-exposure showed no reductive dechlorination activity for both TCA and TCE by 120 days after the re-exposure. It has been hypothesized that the microbial TCE-dechlorinating ability was developed before TCE became abundant in groundwater. This dechlorinating ability would have existed in the microbial metabolism due to previous exposure to biogenic halogenated compounds. After observing the inability of DehaloR^2 to dechlorinate other anthropogenic compounds, DehaloR^2 was then exposed to two naturally occurring halogenated phenols, 2,6-DBP and 2,6-DCP, in the presence and absence of TCE. DehaloR^2 debrominated 2,6-DBP through the intermediate 2-bromophenol (2-BP) to the end product phenol faster in the presence of TCE. DehaloR^2 dechlorinated 2,6-DCP to 2-CP in the absence of TCE; however, 2,6-DCP dechlorination was incomplete in the presence of TCE. Additionally, when 2,6-DBP was present, complete TCE dechlorination to ethene occurred more quickly than when TCE was present without 2,6-DBP. However, when 2,6-DCP was present, TCE dechlorination to ethene had not completed by day 55. The increased dehalogenation rate of 2,6-DBP and TCE when present together compared to conditions containing only 2,6-DBP or only TCE suggests a possible synergistic relationship between 2,6-DBP and TCE, while the decreased dechlorination rate of 2,6-DCP and TCE when present together compared to conditions containing only 2,6-DCP or only TCE suggests an inhibitory effect.
ContributorsKegerreis, Kylie (Author) / Krajmalnik-Brown, Rosa (Thesis advisor) / Halden, Rolf U. (Committee member) / Torres, César I (Committee member) / Arizona State University (Publisher)
Created2012
Description
There is growing concern over the future availability of water for electricity generation. Because of a rapidly growing population coupled with an arid climate, the Western United States faces a particularly acute water/energy challenge, as installation of new electricity capacity is expected to be required in the areas with the most limited water availability. Electricity trading is anticipated to be an important strategy for avoiding further local water stress, especially during drought and in the areas with the most rapidly growing populations. Transfers of electricity imply transfers of "virtual water" - water required for the production of a product. Yet, as a result of sizable demand growth, there may not be excess capacity in the system to support trade as an adaptive response to long lasting drought. As the grid inevitably expands capacity due to higher demand, or adapts to anticipated climate change, capacity additions should be selected and sited to increase system resilience to drought. This paper explores the tradeoff between virtual water and local water/energy infrastructure development for the purpose of enhancing the Western US power grid's resilience to drought. A simple linear model is developed that estimates the economically optimal configuration of the Western US power grid given water constraints. The model indicates that natural gas combined cycle power plants combined with increased interstate trade in power and virtual water provide the greatest opportunity for cost effective and water efficient grid expansion. Such expansion, as well as drought conditions, may shift and increase virtual water trade patterns, as states with ample water resources and a competitive advantage in developing power sources become net exporters, and states with limited water or higher costs become importers.
ContributorsHerron, Seth (Author) / Ruddell, Benjamin L (Thesis advisor) / Ariaratnam, Samuel (Thesis advisor) / Allenby, Braden (Committee member) / Williams, Eric (Committee member) / Arizona State University (Publisher)
Created2013
Description
In situ remediation of contaminated aquifers, specifically in situ bioremediation (ISB), has gained popularity over pump-and-treat operations. It represents a more sustainable approach that can also achieve complete mineralization of contaminants in the subsurface. However, the subsurface reality is very complex, characterized by hydrodynamic groundwater movement, geological heterogeneity, and mass-transfer phenomena governing contaminant transport and bioavailability. These phenomena cannot be properly studied using commonly conducted laboratory batch microcosms lacking realistic representation of the processes named above. Instead, relevant processes are better understood by using flow-through systems (sediment columns). However, flow-through column studies are typically conducted without replicates. Due to additional sources of variability (e.g., flow rate variation between columns and over time), column studies are expected to be less reproducible than simple batch microcosms. This was assessed through a comprehensive statistical analysis of results from multiple batch and column studies. Anaerobic microbial biotransformations of trichloroethene and of perchlorate were chosen as case studies. Results revealed that no statistically significant differences were found between reproducibility of batch and column studies. It has further been recognized that laboratory studies cannot accurately reproduce many phenomena encountered in the field. To overcome this limitation, a down-hole diagnostic device (in situ microcosm array - ISMA) was developed, that enables the autonomous operation of replicate flow-through sediment columns in a realistic aquifer setting. Computer-aided design (CAD), rapid prototyping, and computer numerical control (CNC) machining were used to create a tubular device enabling practitioners to conduct conventional sediment column studies in situ. A case study where two remediation strategies, monitored natural attenuation and bioaugmentation with concomitant biostimulation, were evaluated in the laboratory and in situ at a perchlorate-contaminated site. Findings demonstrate the feasibility of evaluating anaerobic bioremediation in a moderately aerobic aquifer. They further highlight the possibility of mimicking in situ remediation strategies on the small-scale in situ. The ISMA is the first device offering autonomous in situ operation of conventional flow-through sediment microcosms and producing statistically significant data through the use of multiple replicates. With its sustainable approach to treatability testing and data gathering, the ISMA represents a versatile addition to the toolbox of scientists and engineers.
ContributorsMcClellan, Kristin (Author) / Halden, Rolf U. (Thesis advisor) / Johnson, Paul C (Committee member) / Krajmalnik-Brown, Rosa (Committee member) / Arizona State University (Publisher)
Created2013
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
Analysis and modeling of residual compounds in process streams from U.S. wastewater treatment plants
Description
The presence of compounds such as pharmaceuticals and personal care products (PPCPs) in the environment is a cause for concern as they exhibit secondary effects on non-target organisms and are also indicative of incomplete removal by wastewater treatment plants (WWTPs) during water reclamation. Analytical methods and predictive models can help inform on the rates at which these contaminants enter the environment via biosolids use or wastewater effluent release to estimate the risk of adverse effects. The goals of this research project were to integrate the results obtained from the two different methods of risk assessment, (a) in silico modeling and (b) experimental analysis. Using a previously published empirical model, influent and effluent concentration ranges were predicted for 10 sterols and validated with peer-reviewed literature. The in silico risk assessment analysis performed for sterols and hormones in biosolids concluded that hormones possess high leaching potentials and that particularly 17-α-ethinyl estradiol (EE2) can pose significant threat to fathead minnows (P. promelas) via leaching from terrestrial depositions of biosolids. Six mega-composite biosolids samples representative of 94 WWTPs were analyzed for a suite of 120 PPCPs using the extended U.S. EPA Method 1694 protocol. Results indicated the presence of 26 previously unmonitored PPCPs in the samples with estimated annual release rates of 5-15 tons yr-1 via land application of biosolids. A mesocosm sampling analysis that was included in the study concluded that four compounds amitriptyline, paroxetine, propranolol and sertraline warrant further monitoring due to their high release rates from land applied biosolids and their calculated extended half-lives in soils. There is a growing interest in the scientific community towards the development of new analytical protocols for analyzing solid matrices such as biosolids for the presence of PPCPs and other established and emerging contaminants of concern. The two studies presented here are timely and an important addition to the increasing base of scientific articles regarding environmental release of PPCPs and exposure risks associated with biosolids land application. This research study emphasizes the need for coupling experimental results with predictive analytical modeling output in order to more fully assess the risks posed by compounds detected in biosolids.
ContributorsPrakash Chari, Bipin (Author) / Halden, Rolf U. (Thesis advisor) / Westerhoff, Paul (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2012