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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Development of a biophysical system based on bentonite, zeolite and micro-organisms for remediating gold mine wastewaters and tailings ponds

Nsimba, Elisee Bakatula 22 April 2013 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg 2012 / Wastes from mining operations usually contain a suite of pollutants, among them cyanide and its complexes; heavy metals; metalloids and radionuclides. The pollution plume can affect public health through contamination of drinking water supplies, aquatic ecosystems and agricultural soils. As such, waste management and remediation has become an important integral component of mining. Conventional chemical and physical methods are often expensive and ineffective when the pollutant concentrations are very high, so the challenge of developing cost-effective materials with high adsorption efficiencies for pollutants still remains. This research was dedicated to the development of biosorbents with high metal loading capacity for the remediation of mine wastewater, namely: zeolite/bentonite functionalised with microbial components such as histidine, cysteine, sorbitol and mannitol; zeolite/bentonite functionalised with Penicillium-simplicissimum and zeolite-alginate complex generated by impregnating natural zeolite into alginate gel beads. The ability of the fresh water algae, Oedogonium sp. to remove heavy metals from aqueous solutions in batch systems was also assessed. Optimum biosorption conditions for the removal of Co, Cu, Cr, Fe, Hg, Ni, Zn and U (in a single-ion and multi-ion systems) were determined as a function of pH, initial concentration, contact time, temperature, and mass of biosorbent. An increase of adsorption capacity was observed following modification of natural zeolite/bentonite by microbial components with a maximum adsorption capacity obtained at low pH. The FTIR results of the developed biosorbents showed that the biomass has different functional groups that are able to react with metal ions in aqueous solution. Immobilisation of fungi (Penicillium-simplicissimum) on zeolite/bentonite yielded biomass of 600 mg g-1 (10-fold higher than the non-immobilised one) at a pH 4, showing the potential of this sorbent towards remediation of AMD-polluted mine sites. The maximum uptake of metals ions (in a multi-ion system) was higher and constant (40-50 mg g-1) in the inactive fungal biomass (heat-killed) from pH 2 to 7. The uptake of U and Hg increased significantly in the zeolite/bentonite-P.simplicissimum compared to their natural forms due to the presence of the N-H, S-H and COO- groups. iii The pseudo second-order adsorption model was found to be more suitable in describing the adsorption kinetics of metal ions onto biomasses in single- and multi-ion systems with the sorption of nickel being controlled by film diffusion processes (with the coefficient values of 10-7 cm2 s-1). The thermodynamic parameters showed that the adsorption onto developed biosorbents was feasible and spontaneous under the studied conditions. The calculated values of the loading capacities in column adsorption for the natural zeolite/bentonite as well as zeolite/bentonite-P.simplicissimum were close to those obtained in the batch tests, mainly for U and Ni. The bed depth service time model (BDST) was used successfully to fit the experimental data for Ni and U adsorbed on the natural zeolite. This suggested a linear relationship between bed depth and service time, which could be used for scale-up purpose. The developed biosorbents could be regenerated using 1 mol L-1 HNO3 solution for potential re-use. The total decrease in biosorption efficiency of zeolite-Penicillium simplicissimum after five cycles of adsorption-desorption was ≤ 5% which showed that zeolite/bentonite-Penicillium simplicissimum had good potential to adsorb metal ions repeatedly from aqueous solution. On applying it to real wastewater samples, the zeolite-P. simplicissimum biosorbent removed 97% of the metals. Penicillium sp. immobilisation enhanced the potential and makes it an attractive bioremediation agent. The zeolite-alginate sorbent exhibited elevated adsorption capacities for metals. This showed potential for use of such a system for remediation purposes. It also provides a platform to explore the possibility of using zeolite in conjunction with other polysaccharide-containing materials for heavy metal removal from wastewaters. The results obtained in this study have shown that zeolite and bentonite are good supports for biomass. The biofunctionalised zeolite/bentonite systems have potential in removal of heavy metals from wastewaters.
192

A contribuição da Geomorfologia para o conhecimento da fitogeografia nativa do estado de São Paulo e da representatividade das Unidades de Conservação de Proteção Integral / The contribution of geomorphology to the knowledge of native phytogeography in the state of São Paulo and representativeness of the Conservation Units of Integral Protection

Jordão, Silvia 25 October 2011 (has links)
A análise de mapas da vegetação nativa do estado de São Paulo elaborados ao longo dos séculos XIX, XX e XXI, revela diferentes possibilidades de interpretação da fitogeografia estadual, embora revele também muitos aspectos convergentes, como por exemplo, tipos florestais na fachada Atlântica adaptados a maior umidade que aqueles tipos do interior. Em busca de elementos territoriais que favorecessem a compreensão da organização fitogeográfica estadual foi elaborada uma revisão do conhecimento geomorfológico do estado de São Paulo que permitiu individualizar os principais aspectos do relevo paulista. A comparação entre as propostas que descreveram e mapearam a vegetação nativa com os principais tipos de relevo indicou a possível ocorrência de vinte e três tipos de ambientes terrestres com afinidades fitogeográficas, além de dois aquáticos e ambientes de exceção, de ocorrência muito localizada. O reconhecimento deste conjunto de ambientes permitiu ainda a elaboração de uma análise da distribuição das Unidades de Conservação (UCs) de Proteção Integral no território estadual revelando a concentração destas na Serra do Mar Paranapiacaba, seguido pelo Planalto Atlântico, em contraste com o restante do Estado que apresenta grandes vazios e UCs isoladas. A atual área protegida neste tipo de categoria alcança atualmente 3,8% do território paulista. Os resultados finais revelaram que o conhecimento da fitogeografia nativa estadual precisa ser aprimorado para que possa expressar sua real diversidade original e que o relevo pode ser a base territorial para esta organização, agregando dados botânicos, climáticos e pedológicos. Sugere-se que a nova proposta de mapeamento adote uma plataforma digital e escalas entre 1:250.000 e 1:500.000, além de uma classificação fisionômica-ecológica para os níveis superiores, admitindo subdivisões com base na flora ou em condições ambientais específicas. A terminologia poderá ser aquela proposta pelo mapa oficial da vegetação brasileira do IBGE, adaptando-a, no entanto, a condições mais localizadas. Ações voltadas à restauração ou à conservação da biodiversidade, bem como processos de planejamento ambiental-territorial serão tanto melhores quanto melhor forem as bases conceituais e de informação no qual se apóiem. Deste modo a falta de conhecimento fitogeográfico adequado pode induzir a ações que levam a biosimplificação e favoreçam, cada vez mais, a homogeneização de paisagens. / The analysis of native vegetation maps of the state of São Paulo elaborated throughout the XIX, XX and XXI centuries shows different possibilities for the interpretation of the state phytogeography, although it also reveals many converging aspects, e.g., forest types in the Atlantic façade adapted to higher moisture than those located in the interior of the state. A review of the geomorphological knowledge of the state of São Paulo that allowed differentiating the main aspects of the state relief was prepared, in order to seek for territorial elements to promote the understanding of the state phytogeographical organization. Comparison among the proposals that described and mapped the native vegetation with the main types of relief pointed out the possible occurrence of twenty-three types of terrestrial environments with phytogeographical affinities, besides two aquatic environments and exception environments, with very restricted occurrence. Reconnaissance of this set of environments also allowed to prepare an analysis of the distribution of Conservation Units (UCs) with Integral Protection in the state territory that featured the concentration of these units in the Serra do Mar - Paranapiacaba, followed by the Atlantic Plateau, in contrast to the rest of state that has large gaps and isolated conservation units. The current protected area in such category reaches 3.8% of the state territory. The final results showed that the knowledge of the state native phytogeography must be improved to express its real original diversity, and the relief must be the territorial base for this organization, since it adds botanical, climatic and soil data. It is suggested that the new mapping proposal adopts a digital platform and scales between 1:250,000 and 1:500,000, besides a physiognomical-ecological classification for the upper levels, accepting subdivisions based on flora or specific environmental conditions. The terminology should be that proposed by the IBGEs Brazilian vegetation official map, adapted to to more localized conditions. The better the conceptual and information bases are, the better will be the actions focused on biodiversity conservation or restoration, as well as processes of environmentalterritorial planning. Thus, the lack of proper phytogeographical knowledge may induce actions that lead to bio-simplification and make more and more easier the homogenization of landscapes.
193

Transport planning for health : explaining and evaluating barriers and opportunities to intersectoral collaboration

Davis, Adrian Lawrence January 2001 (has links)
No description available.
194

Transfer of low-carbon technology under the United Nations Framework Convention on Climate Change : the case of the Global Environment Facility and its market transformation approach in India

Haum, Rüdiger H. January 2011 (has links)
The transfer of low-carbon technology to developing countries is one of the key means to reduce greenhouse gas emissions in developing countries and therefore a key aspect of the United Nations Framework Convention on Climate Change (UNFCCC). This thesis aims to contribute to the understanding of international low-carbon technology transfer and how it might do justice to the interest of developed and developing countries. The empirical example is the technology transfer approach and its implementation by the Global Environmental Facility, which acts as the financial mechanism of the UNFCCC. My theoretical framework includes two sets of theories. The first includes theories of international technology transfer. This set explains how international technology transfer may lead to economic benefits on the side of the technology recipient. This theory, however, does not explain how international technology transfer will lead to significant environmental benefits. I therefore included a second set of theories in my theoretical framework. Theories of diffusion of environmental technologies explain how technology might achieve environmental benefits such as the reduction of greenhouse gas emissions in developing countries. A case study was chosen as method. In order to do justice to the research question, the empirical enquiry takes place on three interconnected levels. On the first level, the positions of developed and developing countries on the subject of technology transfer under UNFCCC were established. These serve as additional yardsticks for the discussion of the GEF approach and its outcomes. On the second level, the technology transfer approach of the GEF and the relationship to GEF and UNFCCC on the subject on technology transfer was established. On the third level, the GEF project Photovoltaic Market Transformation Initiative (PVMTI) in India, which follows the GEF approach to technology transfer, was investigated. The thesis concludes, in relation to the research question, that the current GEF approach to technology transfer is unlikely to achieve the goals of both developed and developing countries. It is able to achieve the goals of developed countries as it tends to prioritise the environmental goals through selected demand side measures that are effective in achieving emission reductions. It is less effective in achieving development goals as international technology transfer is left to the private actor.
195

Gaining State Response on Global Environmental Problem-Solving: Developing A State-centric Approach

Bothwell, Heather MacGregor 10 July 1995 (has links)
This study focuses on identifying the conditions which encourage or discourage international cooperation with regard to environmental problem-solving. In particular, the divergence between two key international relations theories, Environmentalism and Realism, will be examined in hopes of forging a rapprochement and stimulating research for a comprehensive theoretical approach to global environmental problem-solving. It is hypothesized that a state-centric political system is both a reality and an effective structure for environmental problem-solving, therefore an examination of state participation and the motivators and inhibitors affecting state response on certain environmental issues is conducted. In particular, this study hypothesizes that uncertainty can act as an inhibitor, and without the introduction of motivators can prevent states from participating in environmental problem-solving. A conceptual model of state courses of action is utilized to illustrate the potential of state participation and the development of a state-centric approach.
196

State Cooperation on Regulatory Policies for Transboundary Environmental Issues

Pennell, Jennifer Lyn 06 July 1995 (has links)
This research analyzes three contributing factors, perception, knowledge, and affordability, in order to estimate the likelihood of state cooperation on effective regulatory policies for transboundary environmental problems. The correlative hypothesis in this research postulates that states are more likely to support environmental regulatory policies when the issue is perceived by policymakers as serious, substantiated by a high level of knowledge, and affordable for the state. Regulatory policies for transboundary environmental issues require policymakers to act in foresight, employ precautionary measures, and cooperate. Cooperation implies that states will coordinate their policies and eschew their dominant strategy of independent decision making. However, this research contends that states decide to cooperate because they perceive the strategic interaction to be beneficial. Thus, the theory of cooperation in this research is consistent with realist assumptions of rational egoism.
197

�This must be the place� : plumbing a land ethic for the built environment

Ballantyne, Brian Andrew, n/a January 1995 (has links)
A land ethic within the built enviroment was examined from the perspective of the surveying community in New Zealand. The research followed a structure of context, interpretation and application; used legal analysis; and, sampled the ideologies of iwi liason officers, consultant surveyors, and local authorities. Context involved asking why a land ethic was being debated, by focusing on the current level of environmental thought, and on the actions of the International Federation of Surveyors (FIG) and the New Zealand Institute of Surveyors (NZIS). Some findings are: that terms such as sustainable management and nature are ambiguous cultural constructs; and, that the adoptation of an environmental policy by the NZIS continues to be a tortuous process. Interpretation involved asking what constituted a New Zealand ethic, by putting such an ethic into perspective in relation to ecophilosophy, and by searching for a contemporary sense of kaitiakitanga. Some findings are: that restraint and humility are requirements in any moral theory of nature; that kaitiakitanga is not dependent on title to land; and, that iwi liason officers are divided as to how kaitiakitanga applied to the built environment. Application involved suggesting how a land ethic could be invoked in the built environment, through the provision of green space in the form of local purpose reserves. Some findings are: that surveyors regard reserves as being significantly less vital to a community�s well-being than engineered services; and, that local authorities are not generally aware that reserve policies might have to be linked to municipal open space strategies. The broad conclusions are: that regardless of the environment that now exists, surveyors will be required to make moral choices about the environment that is sought; that a land ethic will not necessarily provide rational prescriptions directing action towards land; and, that there is inherent tension between land tenure, land use and a land ethic. Suggested avenues for further research include a comparative analysis of other landed professions; the empowerment of women within any land ethic; and, the use of content analysis as an alternative methodology.
198

Landscape quality assessment of South Australia

Lothian, Andrew January 2000 (has links)
The object of this thesis is to provide, through a thorough analysis of human perception and interaction with aesthetics and landscape quality, a comprehensive basis on which to develop a credible methodology for the large scale assessment of perceived landscape quality. The analysis of human perception and interaction with aesthetics and landscape quality is gained by inquiring in depth into a range of theoretical constructs from key disciplines, cultural aspects, and empirical studies covering : 1. the contribution of philosophers to aesthetics 2. the psychology of perception and colour 3. the contribution of Gestalt psychology to aesthetics 4. the psychoanalytical construct of human responses to aesthetics 5. the influence of culture on landscape preferences, tracing the changing perceptions of mountains, the portrayal of landscapes in art, and the design of parks and gardens 6. a review of over 200 surveys of landscape quality in the late 20th century, including typologies and theories of landscape quality Based on the analysis of these and the knowledge gained, an empirical study is formulated and conducted, comprising a study of landscape quality of South Australia, an area of nearly 1 million km - 1. This involves, firstly, the acquisition of data covering the delineation of landscape character regions for the State, photography of these landscapes, derivation of a set of representative slides, and rating of these by groups of participants. Secondly, these preference ratings are comprehensively analysed on the basis of the attributes of the scenes covering land form, land cover, land use, water bodies, naturalism, diversity and colour. Thirdly, the results are applied as follows: 1. a map of landscape quality of South Australia is derived 2. the results are used to predict the effect that changes in land use ( e.g. clearance of trees ) will have on landscape quality 3. the theoretical constructs of landscape quality are evaluated on the basis of the preference ratings 4. a protocol is detailed to guide the undertaking of large - scale landscape quality assessment. The thesis thus fulfils the objective of conducting a thorough analysis of human perception and interaction with, aesthetics and landscape quality, to provide a basis for developing a credible methodology for the large - scale assessment of perceived landscape quality. / Thesis (Ph.D.)--School of Social Sciences, 2000.
199

Understanding greenpeace campaigns in China empowerment and mobilization /

Wang, Liang, January 2006 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.
200

Where Old West meets New West : confronting conservation, conflict and change on Utah's last frontier

Leaver, Jennifer Jensen 09 March 2001 (has links)
In the United States during the last 30 years there has been a shift from extractive natural resource-based economies of the Old West to a New West defined by environmental protection. Over the past century, a growing national support for environmental protection has influenced a lengthening list of national and state parks, national monuments, national wildlife refuges, and wilderness areas in the western United States. Increasingly, urbanites seeking outdoor recreation and enhanced "quality of life" are attracted to the rural towns, or "gateway towns," bordering these protected natural areas. Boulder and Escalante, Utah, traditional ranching communities that became gateway towns to Grand Staircase-Escalante National Monument on September 18, 1996, are western rural towns currently experiencing such change. President Clinton created Grand Staircase-Escalante National Monument (GSENM) by invoking the Antiquities Act and thus bypassing congressional approval and National Environmental Policy Act (NEPA) requirements. As a result, the local people of Boulder and Escalante have expressed anger and hostility toward the federal government and environmentalists, which has led to community dysfunction and polarization, leaving Boulder and Escalante in disadvantageous positions as gateway towns faced with the task of planning for increased tourism and population growth. In my thesis I utilize cultural survival theory and perspectives on environmentalism, tourism and growth management to explore the various impacts of GSENM on Boulder and Escalante's local culture and to identify possible remedies or alternatives to these impacts. Methods used in collecting data include background research, participant observation, recent related survey data, and in-depth interviews with Boulder and Escalante residents. Research findings show that GSENM threatens the local culture by infringing on local territoriality, introducing outside values, beliefs and ideas, forcing rapid and unwanted change on a traditional people, and leaving locals feeling voiceless and powerless in the face of change. In sum, I found that a lack of both trust and cultural sensitivity have played roles in fostering community dysfunction and polarization. However, I believe that common ground and community solidarity can be achieved in Boulder and Escalante through the re-establishment of trust, a greater sensitivity toward the local culture, and proper leadership. / Graduation date: 2001

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