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NAPL remediation by vacuum-enhanced recovery: Laboratory and model evaluationsDayal, Prabhu, 1947- January 1996 (has links)
This dissertation presents an innovative methodology in the form of two papers for the feasibility assessment and optimization of Vacuum Enhanced Recovery (VER) to remediate non aqueous phase liquids (NAPLs) in the vadose zone. The first paper demonstrates the use of a pilot-scale two-dimensional laboratory soil cell and an automated dual-energy gamma ray attenuation system for the feasibility assessment of VER to remediate free-product NAPL spills. The investigations were conducted in a 1.5 x 1 x 0.08 meter cell filled with heterogeneous soils for the simultaneous and continuous measurement of NAPL and water saturations at 96 programmed locations. The dynamic laboratory method determines the spatial distributions of three-phase fluid saturations of an oil spill simulation from the surface as it migrates through the vadose zone during the sequential stages of infiltration, redistribution and VER. Contour plots of observed NAPL and water saturations identify the distribution of NAPL as entrapped liquid in heterogeneous soils unavailable for free-product recovery by VER. The accuracy of the methodology used for the measurement of NAPL retention in soil was illustrated by a NAPL retention measurement precision analysis. A mean difference of 0.97% was achieved by comparing gamma system measured NAPL retention volumes in the soil with that derived by the VER system. The second paper utilizes the pilot-scale laboratory results for a comparative analysis with model simulations to calibrate a three-phase model and optimize the design of VER systems for free-product NAPL remediation in heterogeneous soils.
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Deciding and doing what's right for people and planet : an investigation of the ethics-oriented learning of novice environmental educatorsOlvitt, Lausanne Laura January 2012 (has links)
This study probes the ethics-oriented reflexive deliberations of three novice environmental education practitioners in South Africa. Two of the cases examined work in a local government context, and the third in an environmental non-governmental organisation context. All three practitioners are studying a one-year professional development course in environmental education. The research asks how their ethical deliberations ‘come to be what they are’, at the interface of their workplace and course-based learning processes. Working within a relational, social realist ontology, the study takes a sociocultural-historical approach to learning, development and social change. Cultural-historical activity theory (CHAT) provides theoretical tools and a descriptive language to approach the rich, qualitative data derived from workplace and course observations, extensive interviews, and document review. Critical discourse analysis was used as a secondary analytical tool to probe ethical and environmental discourses that were found to be influential in the course and workplace activity systems. Data from the three case studies was analysed in stages. In the first stage, CHAT provided a theoretical perspective and language of description to analyse the interacting activity systems in which each learner-practitioner’s ethics-oriented reflexive deliberations occurred. This provided a platform for the second stage of analysis which was framed by Margaret Archer’s (1995) social realist theory of morphogenesis/ morphostasis, followed by a summative retroductive analysis, to give an account of the interplay of historically-emergent social and cultural structures and individual reflexivity in relation to the ethical dimensions of environmental education practice. The study traces how ethics-oriented reflexive deliberations occur at the untidy, unpredictable intersection of workplace, course and personal contexts, and are strongest when they are situated in authentic contexts that resonate with learner-practitioners’ ‘ultimate concerns’ (after Archer, 2003; 2007). In this study, the learner-practitioners’ ‘ultimate concerns’ included family, personal well-being, social justice, cultural identity and religious commitments. The scope and depth of learner-practitioners’ social-ecological knowledge was also identified as a key factor influencing ethics-oriented reflexive deliberations, although the mediation of such knowledge can be hindered by language and conceptual ii barriers, amongst others. The study also noted how ethical positions circulating in the workplace, course and personal contexts were diverse, uneven and dynamic. Some ethical positions were found to be more explicitly differentiated than others, either resonating with or being overlooked by the learner-practitioners as they deliberated the ethical dimensions of their environmental education practice. In situations where there was limited depth, conceptual clarity and/ or confidence to engage directly with ethical concerns, there was a tendency towards (inadvertent) ethical relativism. Insights derived from the study suggest that these factors have limiting effects on the ethics-oriented reflexive deliberations of novice environmental educators. These insights point to the need for ethical deliberations to be re-personalised in context and underpinned by depth knowledge. A relational and pragmatic approach to environmental ethics (that recognises the validity of judgemental rationality – which can be fallible – and which seeks out practical adequacy) is put forward as appropriate and potentially generative in environmental education and training processes. This would need to be supported by careful attention to the influence of environmental discourses and practices in shaping ethical deliberations, and may also be helpful in developing a much-needed accessible, everyday language of ethical engagement. This study’s contribution to new knowledge in the field of environmental education is through its account of ethics-oriented reflexive deliberations emerging (in the Archerian morphogenetic sense) in complex, indeterminate ways at the interface of sociocultural and social-ecological contexts. The ethics-oriented reflexive deliberations of novice environmental educators occur in relation to their ‘ultimate concerns’ and are advanced or hindered by the historically-emergent practices, discourses and material realities of their workplace, personal and educational contexts. These insights require that the complex interplay of intersecting contexts and concerns that shape ethics-oriented reflexive deliberations be acknowledged and carefully mediated in both workplace-based and coursebased professional development processes.
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环境紧迫感与环境保护承诺 : 社会制度及价值因素如何发挥作用 = Sense of emergency for the environment and commitment to environmental protection : the effects of social institutions and values高艳丽, 30 November 2017 (has links)
随着经济的快速发展,全球环境问题日益严重,不断威胁着人类的生存。环保问题也成为各个领域的学者深入研究的热点。对于社会管理学学者们,目前关于环保问题的研究,最有影响力的理论之一是制度理论(InstitutionalTheory)。但是关于社会制度因素是如何影响个人的环境紧迫感和价值观与环境保护承诺和环保行为之间的关系,这些问题还没有通过实证研究加以回答。本文以制度理论为主理论,研究在个体层面上社会制度因素对环境紧迫感和环境保护承诺之间关系的调节作用。同时比较这三种制度因素,也就是调控性制度因素、规范性制度因素和文化-认知性制度因素,在其调节作用上的相对重要性。本文利用一个来自21 个国家的大样本(N=23443)数据,进行了回归和分层线性模型分析,结果表明三大制度因素均对环境保护承诺和环境保护行为有直接的影响。而且,调控性制度因素发挥着消极的调节作用,而文化-认知性制度因素发挥着积极的调节作用。同时本文针对在目前中国社会制度环境下,人们的环境紧迫感和个人价值观(物质享受需求)与环境保护承诺及环保行为之间的关系,进行了延伸性研究。此部分研究通过对从一家中国企业获得的样本数据(N=245)进行了回归分析,结果表明中国人的环境紧迫感和环境保护承诺呈边缘性显著相关,物质享受需求和环境保护承诺呈显著负相关,环境保护承诺和环保行为呈显著正相关,且环境保护承诺对环境紧迫感和环保行为起到了部分中介作用。其次,本文对实证研究结果进行了理论意义和实践意义的讨论。从理论角度,本文有助于我们理解社会制度对环境保护承诺等个体行为的调节作用。从实践角度,本文提出在环境管理问题上,社会制度不应被忽视。为了在环境保护方面做得更好,企业管理者或环保工作者应该更加关注社会制度因素的调节作用。
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Water Management and Justice in the Borderlands: Perspectives from and Analysis of the Santa Cruz River BasinJanuary 2015 (has links)
abstract: The Santa Cruz River Basin shared by Northern Sonora and Southern Arizona is one example of transboundary water resources in the borderlands region that accurately portrays the complexities of binational management of common pool resources, such as water. Industrialization fueled by trade liberalization has resulted in migration to and urbanization along the border, which have created human rights issues with the lack of water and sanitation, groundwater overdraft of the shared aquifers, and contamination of these scarce resources. Effluent from wastewater treatment plants continues to play increasingly important roles in the region, the use of which has been a source of tension between the two countries. Contributing to these tensions are the strains on binational relations created by border militarization and SB 1070. A shift in water management strategies to increase pubic participation within decision-making, increase the flexibility of the water systems, and increase cross-border collaboration is needed to ensure human and ecological sustainability in the Santa Cruz River Basin. By incorporating direct communication and local capacity as per common pool resource theory, recognizing the connections and implications of management actions through socio-ecological systems understanding, and promoting the organic drivers of change through ecologies of agents, just and vigorous futures can be envisioned and advanced. / Dissertation/Thesis / Masters Thesis Justice Studies 2015
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Effects of a switchgrass buffer strip on soil microorganisms near a field applied with endosulfanClark-Cuadrado, Cristina 13 November 2007 (has links)
A field study to determine the effects of a switchgrass buffer strip (SBS) on soil microorganisms near a field applied with endosulfan was carried out. Soil samples were taken from a SBS and bare soil area downslope from a field applied with endosulfan at different distances, days, and two seasons (wet and dry). Soil samples were analyzed for endosulfan, soil fungi, and bacteria. Analysis of endosulfan concentrations was done by reversed-phase liquid chromatography. No endosulfan runoff was detected by this method. Analysis of soil fungi and bacteria was done by fungal and bacterial enumeration by plate count method on rose bengal agar and tryptic soy agar, respectively.
Soil fungi and bacteria were higher in the SBS than in the bare soil area. Also, soil bacteria was higher during the wet season than during the dry season. The opposite trend was observed for soil fungi.
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The impact of solid and liquid wastes from a rural town on the Chorobamba River Oxapampa, Peruvian AmazonBlanco, Andrea 29 July 2005 (has links)
The goal of this study was to determine the instantaneous vs. integrated effects of waste on the water quality of the Chorobamba River. I sampled 9 stations upstream and downstream of the Town of Oxapampa, Peru during the dry season (June-August) of 2004. I measured in-situ parameters such as pH, DO, temperature, etc. as well as vegetation, riverbank erosion, nutrients (N03, NH4, P04), coliform bacteria and macroinvertebrate communities to determine the current conditions of the river, as well as the integrated effects of pollution. Although water quality conditions remained stable, high fecal coliform concentrations and macroinvertebrate communities indicate deterioration in river health over a longer period of time. If riparian areas along the Chorobamba continue to decrease and if inputs of sewage into the rivers continue to increase, as a function of population, then, conditions will continue to deteriorate in the coming years.
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The treatment of landfill leachate using an MFUF membrane system: Focusing on membrane foulingBanks, Stacie January 2004 (has links)
Membrane systems are being used increasingly throughout the western world to treat landfill leachate as environmental regulations tighten. This work examined leachate filtration using a bench-scale MF/UF membrane system, focussing on surface fouling and constituent reductions at the Trail Road Landfill in Ottawa, Ontario.
The study found that ultrafiltration membranes with a molecular weight cut-off of 10 KDa and below gave the best overall leachate treatment. A 1 KDa ultrafiltration membrane gave the highest percent removals overall of all the membranes tested, but had one of the lowest steady state fluxes ranging from 2 to 5 L/m2h.
Carbonates such as calcite and dolomite were determined to be one of the main foulants/scalants. Iron sulphides or iron oxides tended to form a general coating over the membrane surface and may have been the base for a surface coating of mixed-element origins observed in spring 2003. The fouling type was generally thought to be cake filtration based on flux results and basic fouling determination equations. (Abstract shortened by UMI.)
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Adsorption and desorption characteristics of natural organic matter in natural waters on granular activated carbonStorrar, Megan Denise January 2006 (has links)
The objective of this thesis was to study the adsorption and desorption characteristics of natural organic matter (NOM) adsorbed on granular activated carbon (GAC). Five different natural waters (Ottawa River, ON; St. Lawrence River, ON; Vars Ground Water, ON; Buffalo Pound Lake, SK; Ohio River, OH) were studied to see if the characteristic of irreversible adsorption was a universal phenomenon. This was studied by comparing desorption isotherms to adsorption isotherms. Preliminary long-term kinetic studies were used to ensure that the contact time was sufficient for equilibrium. The waters were also fractionated to further study the differences in adsorption and desorption properties of various surface waters. The fractionation techniques used were; ultrafiltration by membrane separation, extraction of humic acids using a methylmethacrylate resin (XAD8) and size exclusion chromatography using a sephadex gel in a glass column. (Abstract shortened by UMI.)
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Effects of microwave irradiation on the characteristics and mesophilic anaerobic digestion of sequencing batch reactor sludgeThibault, Gabriel January 2006 (has links)
Wastewater treatment generates large quantities of sewage sludge whose disposal is expensive. Mainly because anaerobic digestion produces methane, which can be beneficially used as an energy source, this process has become the most popular means of stabilizing sewage sludge prior to spreading on agricultural land or disposal to landfills. Several pretreatment technologies have recently been developed to render sludge more degradable during anaerobic digestion. The purpose of this study is to investigate whether microwave irradiation can enhance the anaerobic degradability of aerobic sequencing batch reactor sludge.
Relationships relating microwave irradiation duration, microwave intensity, sludge concentration and the temperature reached by the sludge were developed. Sludge concentration in the 1.2-4.3% total solids range was found not to impact the temperature reached by the sludge. Three techniques were used to assess the impact of microwave irradiation on the size of the particles: visual analysis of sludge settling, microscopic analysis and particle size distribution analysis. (Abstract shortened by UMI.)
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Environmental impact statements : a study of content requirements and several assessment methodsDeAngelis, Michael Vincent January 1974 (has links)
Environmental impact statements (EIS) have been required in the U.S. since the National Environmental Policy Act was signed into law on January 1, 1970. Although no legal requirement exists in Canada, in December of 1973 the federal government announced a policy of preparing an EIS for all "major" projects having "significant" effect on the environment
. The evolution of the EIS requirement in the U.S. indicates the major purpose of impact statements is to produce information concerning the full important consequences of a proposal to relevant government agencies, the interested public and to decision-makers so that each person
can reach a rational decision about the social worth of the intended project. The ultimate objective of impact reports and a concomitant public and government agency review process is to facilitate more socially rational decisions about proposed projects. The methodology in this study involved developing a set of criteria based upon the literature to determine whether an EIS has adequately provided
the kind of information in a manner necessary to fulfill its intended purpose. Five impact statements were critically reviewed and discussed in light of several methods proposed for assessing environmental impact. The more important shortcomings identified in the environmental reports were thereby isolated and analyzed. The following general shortcomings were identified in five impact statements critically reviewed: 1) There was some difficulty in comprehensively identifying all important socio-cultural and ecological impacts.
2) Not enough information was always provided so that the reader could value the importance of an identified impact. 3) In some cases an adequate discussion of the curtailment of future beneficial uses of the environment was not completed. 4) An analysis of alternatives was not completed adequately in all impact reports. 5) All impact reports had characteristics which would hinder the communication of information to readers. These shortcomings were generally discussed in reference to different
environmental assessment methods. Three basic conclusions resulted: 1) A comprehensive checklist of impacts should be part of any impact evaluation method used by an agency in order to ensure that all important consequences of proposals are identified. Networks are the most comprehensive type of checklist because they link causal actions to primary, secondary and multiple-order impacts. 2) Evaluation methods which mold economic, socio-cultural and ecological impacts into common units for comparison should not be utilized as a basis for preparing an EIS. These methods judge the importance of each impact for the reader, which is contrary to the main purpose of impact reports. 3) Most evaluation methods identified in this study do not provide guidance in preparing the environmental impact report itself. These evaluation methods would not resolve at least three shortcomings of the impact statements critically reviewed. Therefore, the recommendations of this study consist of EIS preparation
guidelines that enable persons preparing the environmental impact report to avoid the shortcomings which were identified in the thesis. These guidelines relate to the following six points: 1) The purpose and scope of an EIS. 2) Integrating impact reports into the planning process. 3) Recommendations concerning the development of impact checklists.
4) An evaluation approach which defines impacts in separate quantitative and certain key qualitative terms.
5) Several general considerations and a method of summarizing an EIS in order to facilitate impact communication. 6) A flexible and general EIS format which lists most of the important requirements of an impact report. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
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