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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.
271

Plastic waste gasification using a small scale IR reactor : experimental and modelling analysis

Guyemat Mbourou, Sarah Marielle January 2016 (has links)
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016. / The generation of municipal solid waste has increased significantly due to the exponential population growth and it has become a global issue. Gasification technology, an alternative method for waste treatment is a thermochemical process where carbon-based material are exposed to an environment deprived in oxygen, was used for this project. The aim of this thesis is to study the gasification of plastic waste which is a potential alternative energy source using infrared heaters. To achieve this goal, fundamental studies have been numerically and experimentally conducted for an infrared gasifier and subsequently establishing the temperature profile for gasification using a small scale reactor. A detailed study on low density polyethylene was conducted using Infrared Spectrometry and thermal decomposition techniques such as Thermogravimetry and Differential Scanning Calorimetry were performed to establish the temperature at which plastic pellets sample used for this research gasify. The gasification behaviour of pelletized low density polyethylene (plastic pellets) was tested and three case studies were done to evaluate the most suitable temperature profile for the reactor to gasify the low density polyethylene at high temperature for less amount of time. Subsequently, the reactor model was simulated and results validate the use of reactor at an optimum temperature of 800 °C for a gasification process with less residue content. The reactor designed for this research is fully functional and validates the temperature behaviour predicted during simulation. The experimental results show infrared heaters are suitable for gas production using this gasification process.
272

A Review of policies for sustainable solid waste management service in Buffalo City Metropolitan Municipality

Qhayi-Shweni, Nokuzola January 2014 (has links)
Waste is not only harmful to the environment alone but it is also a threat to human health and as such its proper management becomes critical. This study which adopted a qualitative approach focused on the review of policies for sustainable solid waste management service in Buffalo City Metropolitan Municipality in an effort to seek what the municipality’s Solid Waste Department should consider in ensuring that all the communities live in a litter free, clean and healthy environment, and ensure that such a service is received by all communities within its jurisdiction. The most sustainable solid waste management strategy would be to adopt the solid waste hierarchy of promoting waste minimisation, re-use, recycling, waste treatment and disposal as the last resort.
273

A comparative study of the Rooikraal and Marie-Louise landfill sites indicating differences in management strategies, and the consequences thereof on operational and management issues.

Geldenhuys, Lukas Marthinus Marais 18 June 2013 (has links)
M.A.(Geography) / The prevention of environmental deterioration and the concept of sustainable development has become a major concern worldwide. However, increasingly affluent lifestyles along with continual commercial and industrial growth have led to the rapid increase in waste production (Renoua et al., 2008). The most common method of dealing with this production of waste is the disposal thereof by landfill, although this technique is widely viewed as unsustainable. Landfilling is critical to integrated waste management in South Africa due to its simplicity and cost effectiveness (Allen, 2001). Thus, there is a great need for environmentally acceptable landfill management practices. This research is primarily concerned with landfill management strategies and their effect on operational and management issues. A comparative analysis of the Marie Louise and Rooikraal landfill sites was carried out to distinguish differences in landfill management strategies and their outcome on operational and management issues. A concept, indicator, variable approach was used as comparative framework, while external audit reports, landfill management plans, and interviews were used as data sources identifying indicators and variables for analysis. Findings revealed that the Rooikraal landfill has been performing at a high standard, while the Marie Louise landfill has been underperforming due to a number of management failures. Factors that could have contributed to this failure include: external factors and its strain on effective management, capacity of local governments to deliver services with regard to waste management, issues surrounding co-operative governance, legal enforcement and compliance, and lack of control and awareness over landfill operations. These issues are direct consequences of landfill management and operation through municipal entities, making landfill management through municipal entities a key area of concern for effective landfill operations.
274

Design of an anaerobic biodigestion system utilizing the organic fraction of municipal solid waste for biogas production in an urban environment

Kigozi, Robert 25 June 2015 (has links)
M.Tech. (Chemical Engineering) / The design process was carried out in two stages: feedstock analysis and system design. Under feedstock analysis, the study investigated the amount of the organic fraction of municipal solid waste (OFMSW) generated at the study area which was situated at the University of Johannesburg’s Doornfontein Campus (UJ DFC) in downtown Johannesburg South Africa. Furthermore, the feedstock analyses involved characterisation studies on the target waste under which several laboratory tests were undertaken. The system design involved sizing of the suitable biogas digester to be used in the system applying mathematical models and feedstock parameters obtained from the feedstock analyses. Via the application of the Simple Multi-Attribute Rating (SMART) technique of multiple-criteria decision analysis (MCDA) as a decision support tool, the most preferred option of biogas plant model was selected from a list of potential alternatives available on the market. And, in addition, a suitable site around the study area was selected by applying the analytical hierarchy process (AHP) technique of MCDA. Other system components and accessories such as the piping, scrubbers and valves were sized, selected, integrated into the system and finally layout drawings were produced using Inventor computer aided drafting (CAD) Software. Furthermore, feasibility assessments were conducted on the proposed system such as energy usage assessments and economic analyses using the net present value (NPV), internal rate of return (IRR) and benefit-cost ratio (BCR) techniques...
275

A study of the current status of waste management and minimisation initiatives in two district municipal areas of the Gauteng province (West Rand and Sedibeng)

Bhagwandin, Geeta 18 July 2013 (has links)
M.Sc. (Environmental Management) / Over the last eighteen years or so, the Gauteng province has attracted the greatest proportion (45.6%) of foreigners in South Africa. Along with rapid population growth, accelerated rural-urban migration and the rise of low-income houses and informal settlements, some of the District Municipalities around the City of Johannesburg and other urban centres have witnessed increased concentration of population and settlements. In many instances, the capacity of local municipalities to provide adequate infrastructure and services has been severely compromised, especially with respect to the achievement of integrated and sustainable waste management and waste minimisation interventions, including the reuse, recovery and recycling of municipal solid waste. Inevitably, local municipalities are struggling to successfully deliver effective waste management services within their jurisdiction, despite the lack of space for new landfill sites in urban complexes and the promulgation of new laws, regulations and strategies for achieving waste minimisation in South Africa. However, there is paucity of research on how municipalities are performing with respect to waste management challenges and minimisation initiatives, given the new waste management and regulatory regime in South Africa. Considering that the Gauteng-City region has limited space for new landfills, the need to maximise the use, effectiveness and efficiency of current landfill sites is of strategic importance. Hence, this study has examined the effectiveness and efficiency of current waste management and minimisation trends in two District Municipalities in the Gauteng province. To this end, questionnaire surveys have been undertaken in the study areas, making use of purposive sampling methods. The surveys undertaken targeted key individuals in the municipalities and some of the managers of landfill sites. The survey also included the role of informal waste reclaimers and the quantities of waste they recover and sell as well as some of the operational barriers they are experiencing. Findings emanating from this study indicate that more emphasis is placed on the traditional waste management approach through ‘unsustainable’ landfilling rather than providing an enabling management framework for enhancing and promoting waste minimisation through waste prevention and recycling. Failure by local municipalities to encourage waste recycling initiatives is of serious concern, especially in view of the fact that existing landfill sites in West Rand District Municipality have a limited lifespan. The need to preserve landfill space is therefore vital and the best way to achieve this is to reduce the amount of waste being disposed off. The current practice of unrestricted solid waste generation and its disposal and the low level of waste recycling suggests that most local municipalities in the study area lack the capability to make a substantial contribution to waste minimisation. For further research, it is recommended that more surveys should be undertaken in other Metropolitan Municipalities of the Gauteng province, including the City of Johannesburg, City of Tshwane and Ekurhuleni. Such studies would provide additional insights on the extent of waste minimisation in these areas and whether or not the goals of integrated and sustainable waste management are being achieved in South Africa.
276

The impact of and solutions to electronic and electrical waste management in Hong Kong SAR

Zhang, Chan 01 January 2010 (has links)
No description available.
277

An economic evaluation of waste telecommunication cable disposal in South Africa : a case study

Lottering, Tony January 2008 (has links)
South African manufacturers, including those who produce electrical and telecommunication cables, are required by the National Waste Management Strategy (NWMS) (drawn up by the Department of Environmental Affairs and Tourism (DEAT)), to carry out waste management in a coordinated and controlled manner. It is also becoming more difficult for South African companies, who produce for export markets, to conduct business internationally if they do not have some form of environmental management system in place. While there will always be scrap generated in any manufacturing environment, the aim is, first and foremost, to reduce this to acceptable levels and, secondly, to dispose of all scrap produced in a socially responsible manner. This study focuses attention on waste management, in the form of recycling, in the cable manufacturing industry. The purpose of this study is twofold: first, to examine the economic case, by means of a cost-benefit analysis, for the establishment and operation of a telecommunication cable waste recycling plant for the purpose of recycling copper conductor; second, to examine the economic feasibility, by means of a cost-benefit analysis, of extending the existing facility in order to accommodate the recycling of the plastic fraction contained in the cable waste. A specific cost-benefit stream was generated over a project period of 20 years for both CBAs. In both CBAs costs and benefits were categorised as being either primary or secondary. The primary costs and benefits for both CBAs were all financial in nature and were valued using market prices. The secondary costs of establishing and operating a cable waste recycling plant for recycling the copper conductor included effluent costs and noise pollution costs. The secondary benefits, on the other hand, included the creation of downstream industries. The secondary costs of extending an existing cable waste recycling plant, so as to accommodate the recycling of the plastic component of cable waste, included costs related to the generation of greenhouse gases and asthma. The secondary benefits, conversely, included the increase in house prices due to the reduction of landfilling of the plastic component of cable waste. The determination of increased house prices due to landfill avoidance was carried out using the hedonic pricing method (HPM). The hypothesis was that house values would increase the further removed they were from the landfill site. Applying regression analysis to the derived hedonic pricing (HP) function showed that there is a definite correlation between the two. Properties positioned two kilometres from a landfill site in New Brighton Port Elizabeth, Eastern Cape, were found to have higher values than those positioned adjacent to the site. From the cost-benefit streams, net benefits were calculated for each CBA and discounted to present values in order to provide a standard of comparison. The social discount rate used in this study to calculate the present values reflected a combination of the social opportunity costs of capital and the social time preference rate. The rate used was calculated as the average annual rate between 2000 and 2005 and amounted to 6.72 percent. It was derived from a combination of the opportunity costs of government borrowings, household consumption borrowings and return on savings.
278

The effect of legislation on informal waste salvaging and salvagers on official landfill site : the case study of Weltevreden (Polokwane)

Thaba, Makgafela Richard 01 August 2012 (has links)
M.A. / In present-day society, solid waste can no longer be treated as a non-valuable resource. Municipal waste produced from residential and commercial sources has become an economic resource for the poor on landfill sites. Urban poor, rural-urban migrants and urban-urban migrants are the ultimate symbol of the informal economy on landfill sites. These migrants have identified waste as an economic resource to extract a livelihood. In their presence on landfill sites, South Africa has introduced waste management policies which endorse the notion of sustainable development. Sustainable development is the notion through which South Africa shapes and parallels its environmental directive to avoid destruction and depletion of natural resources. Sustainable development is a theoretical framework adopted by this study to evaluate the effect of legislation on informal waste salvagers and waste salvaging. Waste salvaging is often frowned upon and neglected by local municipal authorities who are constitutionally mandated to ensure preservation of natural resources. Amongst other things, local municipalities need to recreate economic opportunities and curb the unemployment rate. Furthermore, South African municipalities deliberated during the tabling of the Polokwane Declaration to reduce waste disposal by 50% in 2012 through waste recycling and waste minimisation. In the absence of employment opportunities, local municipalities in South Africa are continually faced with the dilemma of incorporating informal waste salvaging into their waste management directives. This study uses Weltevreden landfill site in Polokwane as a case study to evaluate the effects of legislation on informal waste salvaging. A waste management and sustainability framework towards career waste salvagers was developed as a paradigm to incorporate elements of sustainable livelihood approach. The framework allowed the study to comprehend the synergy and the discords that waste management directives in South Africa unravel on informal waste salvaging. Furthermore, this led to the procreation of a model to unlock the economic potential of waste in South African municipalities. The model recognises the elements of waste management directives such as National Environmental Management Act, 1998 (Act No.107 of 1998) and National Environmental Management: Waste Act, 2008 (Act No. 59 of 2008). Despite that, the model resonates on the promulgations made in the Waste Act, 2008 (Act No. 59 of 2008) on informal waste salvaging. This study intends to evaluate the extent to which contemporary waste management directives in South Africa support waste salvaging within the three pillars of sustainable development, namely economic, social and environmental. However, this research hypothesises that waste management directives in South Africa fail to support the three pillars of sustainable development. In light of the hypothesis, this research has identified waste salvagers, waste Thaba Makgafela Richard iii management officials and the public as instrumental respondents to evaluate perceptions and challenges linked to the informal waste economy. A desktop review of available regulatory instruments informed recommendations and the model procreated in this study. The key lessons are highlighted and followed in Chapter 7 which provides analytical conclusions and recommendations for all the chapters.
279

Evaluation of the Economic, Social, and Biological Feasibility of Bioconverting Food Wastes with the Black Soldier Fly (Hermetia illucens)

Barry, Tami 08 1900 (has links)
Food waste in the waste stream is becoming an important aspect of integrated waste management systems. Current efforts are composting and animal feeding. However, these food waste disposal practices rely on slow thermodynamic processes of composting or finding farmers with domestic animals capable of consuming the food wastes. Bioconversion, a potential alternative, is a waste management practice that converts food waste to insect larval biomass and organic residue. This project uses a native and common non-pest insect in Texas, the black soldier fly, which processes large quantities of food wastes, as well as animal wastes and sewage in its larval stage. The goal of this research is to facilitate the identification and development of the practical parameters of bioconversion methods at a large cafeteria. Three major factors were selected to evaluate the practicality of a bioconversion system: (1) the biological constraints on the species; (2) the economic costs and benefits for the local community; (3) the perception of and interaction between the public and management agencies with respect to the bioconversion process. Results indicate that bioconversion is feasible on all levels. Larvae tolerate and consume food waste as well as used cooking grease, reducing the overall waste volume by 30-70% in a series of experiments, with an average reduction of 50%. The economical benefits are reduced collection costs and profit from the sale of pupae as a feedstuff, which could amount to as much as $1,200 per month under optimal conditions. Social acceptance is possible, but requires education of the public, specifically targeting school children. Potential impediments to social acceptance include historical attitudes and ignorance, which could be overcome through effective educational efforts.
280

Attitudes and behaviour of low-income households towards the management of domestic solid waste in Tafelsig, Mitchell's Plain

Nshimirimana, Jules January 2004 (has links)
Magister Artium - MA / Solid waste management in South Africa has been focussing on the technical issues of waste disposal with little attention paid to the social and economic aspects of households. It is important to find out the impact of the attitude and perception of households on solid waste management, especially in low-income areas to be able to deal with the deplorabe domestic solid waste management in such areas. The quantity of solid waste generated in low-income areas is often assumed to be less than the solid waste generated in high-income neighbourhoods. In most of the townships of low-income households in Cape Town, the residents live next to mountains of solid waste which is not the case in middle and high income areas. This clearly has a negative effect on the environment and human health. Tafelsig is one of the low-income Cape Flats townships where the open spaces and green areas are dumping areas. The small yard that people own is often unclean. The aim of the study was to examine how households residing in the low-income neighbourhood (Tafelsig, Mitchell's Plain) view domestic solid waste and its management. The study explored the perceptions, attitudes and behaviour of these households towards the production and management of sold waste. Issues relating to the degradation of their environment and to solid waste mismanagement were also examined. / South Africa

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