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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.
61

Demand for green electricity amongst business consumers in the Western and Northern Cape of South Africa

De Villiers, Cecile A. 12 1900 (has links)
Thesis (MBA)--University of Stellenbosch, 2010. / Climate change is one of the most serious issues the world is facing today. With an economic slowdown globally, huge food shortages and record-high fuel prices, it has never been so important for countries to guard their natural resources to ensure future sustainability. The South African energy generation industry, of approximately 40 000 Mega Watt (MW), consists largely (90%) of coal-fired power stations, with the remainder comprising of nuclear and pumped storage schemes which are regarded as environmentally neutral. It is only recently that Eskom and independent power producers (e.g. Darling Independent Power Producer Wind farm with an estimated 10 MW) embarked on utilising South Africa's natural resources to generate electrical power. South Africa's access to inexpensive coal and paid off coal-fired power stations has made it difficult to justify the investment in renewable energy. However, on 31 March 2009 South Africa became the first African country to introduce a feed-in-tariff for renewable energy (Gipe, 2009). The hope is that this initiative would stimulate the investment in green energy generation. Eskom and municipalities are currently the only entities that have licences from the National Energy Regulator of South Africa (NERSA) to buy bulk electricity from power producers. The question therefore arises: if green electricity is more expensive to generate and is sold at a price premium to Eskom and municipalities, would they pass the premium on to consumers; can they differentiate the green electricity product and will consumers be willing to buy at a premium price? This research study aims to answer if businesses would be willing to pay a premium for green electricity, why they would be willing to buy it, which factors influence the purchasing decision and what barriers exist that will deter a purchase. A survey was conducted on businesses in the Western and Northern Cape of South Africa. The businesses sampled have a notified maximum demand of 50kVA or higher and excludes the re-distributor (City of Cape Town) customers. Approximately ten per cent of businesses would be willing buy green electricity. Most of these businesses have indicated that they are willing to pay a premium of five to nine per cent for green electricity. The businesses that are willing to pay the largest premiums (>10%) are in the electricity, gas, water, finance, insurance, real estate, business services, manufacturing, transport, storage and communications sector. Businesses that are willing to buy green electricity: • Have a strategy to reduce their carbon footprint; • Want to be community leaders (altruistic motivators); • Have as their biggest barrier the additional cost of green electricity; and • Feel that power utilities should be required to include a minimum percentage of green energy in their energy mix.
62

Public policy and clean energy venture capital private equity investments in South Africa

Dzenga, Bruce 03 1900 (has links)
Thesis (MDF)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In 2007, Bürer and Wüstenhagen (2009) conducted a survey amongst European and United States venture capital and private equity investors (VC/PE) to ascertain their public clean energy policy preference and concluded that VC/PE investors view the feed-in tariff (FIT) scheme to be the most preferred policy option. In this research study, the author re-conducted part of the Bürer and Wüstenhagen (2009) survey with thirty South African VC/PE investors to determine their perceptions on clean energy public policy preference. It is evident from the survey, that opinions are varied and at times even contradictory. This in itself demonstrates an important feature of the South African VC/PE and clean energy industry: it is young, dynamic, changing rapidly and can look very different, depending on the vantage point. The investors surveyed were mainly optimistic about the long-term development of the South African renewable energy industry led by private investors. VC/PE investors in South Africa have mixed views on various investment options, and are concerned about both the regulatory and macro-economic trends. The interviews and survey results show a number of recurring issues. Altogether, the survey results indicate that VC/PE investors consider FITs to be the best public clean energy policy instrument in leveraging private investment and finance for renewable energy in South Africa. This study serves to illustrate and confirm, in line with empirical studies, that VC/PE investors in South Africa believe that clean energy market-pull policies provide an impetus and indeed spur private investor participation in clean energy in developing countries. While it is true that most VC/PE investors would prefer the price certainty associated with a FIT regime, this is almost an irrelevant question in South Africa since constitutionally the state is bound to procure through competitive tendering. This study also serves to highlight the need for more active research and attention in this field.
63

Use of remote sensing and GIS in a risk assessment of gold and uranium mine residue deposits and identification of vulnerable land use

Sutton, Malcolm William 29 April 2013 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Science Johannesburg, November 2012. / Acid rock drainage (ARD) and dust are potential consequences of gold and uranium mine residue deposits (MRDs) on the Witwatersrand basin. Urbanisation has taken place around mines and, with the curtailing of mining activities and clearing of land previously covered by MRDs, there is pressure to use this land for residential, industrial and agricultural purposes. However, mining companies historically were not required to provide pollution control measures and there is evidence for contamination of land and water. Thus, there is a need to prioritise contamination sources for mitigation and to understand the extent of contamination and potential risks associated with different categories of land-use on mining land. The aim of my study was to conduct a first-order risk assessment to aid in identifying vulnerable land use in the vicinity of gold and uranium mining, and prioritising MRDs, including footprints, for mitigation. To achieve this I constructed a Geographical Information System (GIS) using publicly available spatial data, and then tested the usefulness of historical aerial photographs and remote sensing imagery for mapping MRDs and impacts of MRD origin under Highveld conditions (i.e. a seasonal climate with summer rainfall and annual evapotranspiration of >2.5 times mean annual precipitation). The Ekurhuleni Metropolitan Municipality (EMM; 1923 km2) is an area of extensive historical mining with major urbanisation, while retaining areas for agricultural land use; thus it was selected as a representative study site. I used a numerical rating scheme, which combined a number of parameters in two separate stages to calculate a risk index. The first stage involved the classification of hazards associated with MRDs while the second involved an assessment of land use vulnerability based on exposure pathways and proximity. Historical aerial photographs (1938, 1964 and 2003) and the Chamber of Mines (CoM) Dump Indexes were used to identify and classify MRDs in terms of basic geotechnical properties, current status and historical failure. Multi-spectral data, acquired over two years (2002 and 2003) in two seasons (spring and summer) by the TERRA satellite’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor, were used to compile thematic images, indicating potential contamination of surrounding land. It was intended that a zone of influence could be distinguished for each MRD enabling me to rate the hazard severity. The thematic images I selected included primary minerals (pyrophyllite and chlorite), secondary minerals (copiapite and jarosite), an indicator of uranium-bearing ore (referred to as mincrust) and the normalised difference vegetation index (NDVI). These minerals were chosen as potential indicators of different transport routes of contaminants and I tested their associations with different features and land use. I also tested for seasonal differences in the detection of these minerals, and used NDVI to examine the masking effect of active vegetation. I found GIS to be well suited for combining the various forms of spatial data and providing information about MRDs, aqueous pathways, proximity to vulnerable land uses and impacted areas. However, I found that the potential severity of the hazards posed by each MRD, as indicated by a zone of influence, could not be determined from aerial photographs and ASTER alone. I therefore utilised the findings expressed in the literature survey to assign ratings for the different classes of MRDs. The vulnerability assessment was also supplemented by literature review to rate land uses based on human exposure pathways. I determined that MRDs (including footprints) cover 4.1% of EMM, with slimes dams, totalling 3.5%, occupying the majority of this area. I found that 64% of slimes dams had failed prior to 2003 and I plotted a further 0.6% of EMM covered by visible mine residue spillage. Fifty three percent of MRDs were situated within 100 m of drainage lines or old wetlands, while 52% of these (i.e. 27% of the total) had been constructed in the watercourse. I also found that 15% were constructed on dolomites. Informal settlements were located on or bordering 6% of MRDs, with 41% of MRDs within 1 000 m. Eighty eight percent of MRDs were found within 1 000 m of formal residential areas, 71% within 500 m, and formal settlements were located on or bordering 5% of MRDs. Twenty three percent of MRDs were located within 500 m of agricultural land, while 35% were within 1 000 m; and industrial land use was on 9% of MRDs (footprints), with 40% of MRDs being within 500 m of industrial areas and 61% within 1 000 m I found that chlorite did not provide a ‘signature’ of gold and uranium mine residue, whereas the other four minerals did. I also found that, of the two seasons examined (spring and summer), the best time to take an ASTER image to detect mineral signatures of gold and uranium mine contamination is after a few dry days following the first spring rains. For this reason, I used the ASTER taken in late October (spring) 2003 to examine associations with pathways and land use. I found more pyrophyllite and copiapite on industrial and business land use than background, which I suggest is associated with the settling of windborne dust on large and flat roofs; although, in the case of copiapite this could be related to the oxidation of settled wind blown pyrite material. I found jarosite to be a reliable indicator of mine residue, which, together with mincrust, helped me identify contamination in former agricultural holdings, which are now a township. Although, chemically undefined, mincrust was a useful indicator of contamination, as I found it to be reliably detected on MRDs (including footprints), mine residue spillage, wetlands and other contaminated sites, and absent from known uncontaminated sites. Furthermore, it was not necessarily masked by active vegetation, whereas copiapite, jarosite and pyrophyllite were. Mincrust was also detected on irrigated agricultural land with an odds ratio of between 10 to 36 times greater than for rain-fed. Consequently, the most likely pathway for mincrust is the aqueous. The mincrust signature, together with historical aerial photographs, also assisted me to identify historical mining along Black Reef outcrops, through detection in a wetland upstream of known mining activities. The culmination of my study was a risk class and index for MRDs from which ‘risk maps’ were produced. These maps provide a guide to the level of risk posed by each MRD to the surrounding land use. Of the total 287 MRDs (including footprints) identified in the EMM, 50% were classified lower-risk; 40% medium-risk; 10% higher-risk and 0% as much higher risk. The lower-risk MRDs were predominantly rock dumps, whereas the higher-risk MRDs were slimes dams. The findings from my study will contribute to meaningful recommendations for future land use and enable mining companies, landowners, developers and government to allocate their resources judiciously (i.e. appropriate to the level of risk). The results of this study have been published as: Sutton, M.W., Weiersbye, I.M., Galpin, J.S and Heller, D., 2006. A GIS-based history of gold mine residue deposits and risk assessment of post-mining land uses on the Witwatersrand Basin, South Africa. In: A. B. Fourie and M. Tibbett (eds.), Mine Closure 2006: Proceedings of the 1st International Seminar on Mine Closure, Perth, ISBN: 0-9756756-6-4, pp. 667–678 (Appendix I). Sutton, M.W. and Weiersbye, I.M., 2007. South African legislation pertinent to gold mine closure and residual risk. In: A.B. Fourie, M. Tibbett and J. Wiertz (eds.), Mine Closure 2007: Proceedings of the 2nd International Seminar on Mine Closure, Santiago, ISBN: 978-0-9804185-0-7, pp. 89–102 (Appendix II). Sutton, M.W. and Weiersbye, I.M., 2008. Land use after mine closure – Risk assessment of gold and uranium mine residue deposits on the eastern Witwatersrand, South Africa. In: A.B. Fourie, M. Tibbett, I.M. Weiersbye and P.J. Dye (eds.), Mine Closure 2008: Proceedings of the 3rd International Seminar on Mine Closure, Johannesburg, ISBN: 978-0-9804185-6-9, pp. 363–374 (Appendix III).
64

Effect of microbial consortium on the biokinetic test for assessing acid rock drainage potential

Golela, Mhlangabezi Tolbert January 2018 (has links)
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Acid rock drainage (ARD) is one of the most severe environmental challenges currently faced by the mining industry worldwide. ARD is formed from the oxidation of sulphide-bearing minerals, particularly pyrite, in the presence of water and oxygen. ARD generation is accelerated by the presence of naturally occurring iron and sulphur-oxidizing micro-organisms, which regenerate leaching agents that facilitate sulphide mineral oxidation. ARD pollution is characterized by a high concentration of metals and sulphates in solution, low pH and a high salt content (salinity) in the environment, contaminating soil and groundwater. In South Africa, ARD is a major challenge in the gold and coal mining industries, where millions of tons of sulphide waste rock and overburden are generated and discarded. Characterization of these waste materials is required to develop an appropriate disposal strategy to minimise the risk of pollution and the generation of ARD. Potential ARD generation prediction from waste rock depends on the precise characterization of ARD potential using Biokinetic tests. Commonly used ARD prediction methods are static and long-term kinetic tests. Static tests provide data for a worst-case scenario focussing on strong acid chemical leaching potential to give an overall acid forming potential of a sample. Such kinetic tests provide data illustrating the rate of the net acid generation capacity of mine waste. However, these tests are capital intensive and time-consuming and fail to provide adequate information on the effect of micro-organisms on the overall net acid generation capacity of mine waste. The Biokinetic test reported herein and developed at the University of Cape Town, focusses on addressing a worst case scenario provided by static tests in a cost-effective manner and reduced time frames provided for by conventional kinetic tests. This test primarily provides relative rates of ARD generation in the presence of micro-organisms within 90 days. However, the Biokinetic test is at the developmental stage and thus far, has not been consistently used for different waste ores to determine a standardised approach. Therefore, the aim of this study was to investigate the effects of microbial consortia and to develop a standardisation approach for the test for ARD formation potential using gold-bearing and copper-bearing waste rock. Additionally, to refine the Semi-continuous Biokinetic test simulation, a flow-through system where there is minimal seepage in the waste deposit, was also developed. The sulphur content of the gold and copper-bearing samples used in this study was between 2.3 and 3.15%, respectively. These waste rock samples were found to be potentially acid- forming. In the Biokinetic test, finely milled waste rock samples were slurrified, inoculated with consortia and cultured under standard bioleaching conditions. Leaching and acidification rates were monitored.
65

The obligation to rehabilitate mining areas : post mining activities

Madalane, Thembi January 2012 (has links)
Thesis (LLM) -- University of Limpopo, 2012 / The study focuses on rehabilitation, since absence of proper rehabilitation process result in indelible damage to the environment. South Africa, like many other countries, is faced with many environmental problems caused by mining. These problems are particularly caused by, inter alia, abandoned mining areas without rehabilitation, inadequate environmental impact assessment after closure, inadequate financial provision for rehabilitation, and lack of monitoring and aftercare system after post mine closure. The study found that many Companies ignore laws governing prospecting, extraction and rehabilitation. The main purpose of this research is to investigate and recommend guidelines in the rehabilitation process so as to instil respect for the environment. The study therefore recommended strict legislation relating to environmental protection against mining.
66

Non-occupational exposure to silica dust at ga-Maja village in Polokwane, Limpopo Province

Kekana, Mokoko Percy January 2006 (has links)
Thesis (MPH.) --University of Limpopo, 2006 / Studies conducted on people who reside next to dust producing mines and industries show major health risks. Air pollutants from the mine and industries are inhaled by exposed miners and people who live in the vicinity (Steenland, 1995). Aim The aim of the study is to investigate non-occupational exposure to silica dust at gaMaja village in Polokwane, Limpopo Province. Methodology Study design For this study a cross sectional descriptive study design was used. Study site The study was conducted at gaMaja village near Polokwane in the Limpopo Province Sampling A total sample of 200 villagers participated in the present study. vi Data Collection Two hundred questionnaires were used to collect survey data and were coupled with four dust deposition gauges. The four gauges were mounted at four different positions in the village and were left for six hours. Data Analysis Questionnaires were analysed using SPSS computer software to determine silica-related illnesses and indicators of exposure to silicosis susceptibility. Dust samples from dust deposition gauges were analysed using a Varian 110 atomic absorption spectrometer for determination of silicon. Results The majority of both male and female participants reported that they do not wheeze (81.4%) or bring out phlegm from their chest (71.4%) as compared to those who reported episodes of cough (48%). Gauges were able to identify exposure to a particular pollutant, silica dust, and were successful.Discussion Data from questionnaires revealed that villagers do not show signs and symptoms related to silicosis, however, that does not rule out infection in a long run. The results from dust samples that were collected reveal that there are traces of silica (crystabolite) in the village of gaMaja. Dust samples were collected during normal production at the mine in the middle of summer. Conclusion Findings from this study show that people residing next to dust producing mines and industries are at high risk of health hazard. Mining companies and policy makers should take note of the findings while planning preventive strategies for reduction of air pollutants.
67

Mining in national parks : a case study--An integrated environmental evaluation of possible magnesite mining in Weetootla Gorge within the Gammon Ranges National Park, South Australia

Stoll, J. A. E. (Julie-Ann E.) January 1989 (has links) (PDF)
Bibliography: leaves 146-152.
68

Plants in the garden: an approach to modeling the impact of industrial activities in ecosystems

Reap, John J. 09 April 2004 (has links)
Humanity's interactions with the supporting environment are, to state the obvious, complex. Humanity's industrial activities effect the environment over time and space, and the same activities even produce different results in different locations. Since the complexities of these interactions may preclude the successful use of eco-performance metrics, humanity may need a means of informing environmental management decisions that accounts for changes with time, spatial patterns and local uniqueness. The objective of this effort is to interface engineering and ecological systems models to better estimate environmental impacts by modeling the dynamic, spatially explicit and location dependent changes caused by industrial activities. Building upon previously developed, dynamic, spatially explicit, location specific ecosystem modeling software, a technical framework for estimating the impacts of industrial systems in ecosystems is developed. Ecological disturbances endemic to engineering systems are integrated into these existing ecosystem models. The results of these integrations are discussed, and from these results, the potential for estimating impacts using dynamic, spatially explicit and location based modeling is evaluated. In other words, one learns the result of placing industrial plants in mother natures garden.
69

Sustainable waste treatment in Hong Kong

Li, Yuen-chi., 李宛芝. January 2006 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
70

Environmental impacts of prospecting and mining in Namibian national parks : implications for legislative compliance

Mansfeld, Christina 04 1900 (has links)
Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2006. / Namibia’s environmental legislation is fragmented and outdated, and in particular mining and prospecting in parks of Namibia is poorly legislated. This problem was analysed with the Skeleton Coast Park being chosen as the study region, as it was considered to be a representative example for parks in Namibia. The Skeleton Coast Park offers both pre-mining and post-mining characteristics; therefore affording the possibility to ascertain the environmental impacts that mining and prospecting have on the environment. The aims of the study were to illustrate the gaps in legislation in regard to mining and prospecting in parks of Namibia and to provide management guidelines for mining and prospecting in these parks. Objectives of this study included gathering baseline environmental information for the Skeleton Coast Park; creating and analysing a spatial database for the occurrence and type of current prospecting and mining activities in the Skeleton Coast Park; analysing and documenting techniques currently practiced for prospecting and mining; and identifying shortcomings in legislation and policy guidelines regulating these activities. The study results highlight the extraordinary sensitivity and uniqueness of the natural environment in terms of physiography, ecological functioning and vulnerability to human interference of the life forms occurring here. Results confirm that mining and prospecting techniques can have detrimental environmental effects given the poor management practices recorded. Also, prospecting in the Skeleton Coast Park indicates no lucrative source of diamonds. Even though currently the entire coast line is given out to Exclusive Prospecting Licences, results do not indicate that any company is undertaking serious active prospecting. Regarding regulation it is evident that new, more encompassing legislation has been drafted, but that the promulgation of the legislation is hampered by the non-finalisation of the process. Several new draft bills currently in place contradict each other and need proper alignment.

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