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- All Subjects: Groundwater
- All Subjects: policy
- Creators: Bennett, Ira
- Member of: Theses and Dissertations
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
A comprehensive review of the managed retreat literature reveals mixed feelings towards the legality, practicality and cost of the policy action as a way to react to rising sea level and coastal erosion. Existing research shows increasing costs of severe storm damage borne to insurance companies and private citizens, furthering the need for long-term policy actions that mitigate the negative effects of major storms. Some main policy actions are restricting development, strategically abandoning infrastructure, funding buyout programs, utilizing rolling easements, and implementing a variety of protective structures. These policy actions face various problems regarding their feasibility and practicality as policy tools, including wavering public support and total costs associated with the actions. Managed retreat specifically faces public scrutiny, as many coastal property owners are reluctant to retreat from the shore. This paper will use examples of managed retreat in other countries (Netherlands, Belgium, and France) to develop plans for specific municipalities, using their models, costs and successes to generate in-depth policy plans and proposals. When observing Clatsop County, Oregon and assessing its policy options, its established that the best policy option is a combination of beach nourishment and Controlled Reduced Tides. This paper analyzes several features of the county, such as the importance of its coastal economic activity and its geographical makeup, to decide what policy actions would be best to mitigate its risk from sea level rise and flood damages. The process used to determine the best course of action for Clatsop County can be replicated in other municipalities, although the resulting policies will obviously be unique to the area.
ContributorsBarry, Matthew John (Author) / Wells, David (Thesis director) / Bennett, Ira (Committee member) / School of Public Affairs (Contributor) / Department of Economics (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05