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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

A process for the detanning of chrome leather wastes utilising tannery effluents

Glaum, Deanne Melanie January 1994 (has links)
The considerable volume of chromium-bearing wastes generated during the process of leather tanning, exacerbated by the potential for trivalent chromium in the wastes to be oxidised to the toxic hexavalent state, has created a major waste disposal dilemma for the tanning industry. While methods are available for the safe and effective treatment of residual chrome-tanning liquors, little has been done to address the issue of the chrome-bearing solid wastes. Given the increasingly stringent environmental compliance standards facing tanneries, unless an appropriate treatment process is developed in the immediate future, the continued use of chromium as a tanning agent could be compromised. Recent investigations have demonstrated the potential of heated alkaline conditions for dechroming these solid wastes. This study expanded upon these considerations and examined the feasibility of utilising the highly alkaline tannery waste effluents as cost-effective, substitute alkaline media. The three effluents considered in this study, classed as lime sulphide liquors, were shown to be capable of dechroming wet blue shavings, with resultant separation of the solid wastes into a protein and a concentrated chromium product. The solubilised protein product contained low chromium concentrations which comply with legal discharge limits. The precipitated chromium product offers opportunity for reutilisation in the tannery. A novel industrial-scale treatment process, based on these investigations, indicated the process to be capable of treating the quantity of shavings produced on a daily basis by a medium to large scale tannery. Application of this method for the dechroming of other chrome-tanned solid wastes was also shown to be feasible.
62

The development of a marketing strategy for a tannery waste by-product

Mkhonta, Mpendulo Colin January 2010 (has links)
Worldwide chromium waste from tanneries is a major environmental concern. A considerable amount of effort is being implemented by tanneries to resolve the environmental concerns. Because of the wide range of chemicals used in tanning, waste treatment is an important issue in the industry. All the tanneries put considerable money and effort into treating their effluent. South African tanneries currently have various methods of disposing of their chrome waste. Most have systems for recycling the waste and disposing of it in municipal waste dumps or it is dumped on the company's own land. Hence the cost of disposal varies widely. Some companies are forced to pay excessive amounts to dispose of their waste at hazardous waste dumps. Others appear to get away by using municipal dumps. Trivalent Chrome (Pty) Ltd offers a solution to the environmental concern by extracting the most dangerous compound in the waste and converting it to a by-product (green chrome oxide). However, the company must be able to then sell of the green chromium oxide. The study seeks to address how the company can market the by-product.
63

Decentralized management of urban food waste: A proof of concept with neighborhood-scale vermicomposting in Montreal, Canada

Schmid, Marian January 2022 (has links)
No description available.
64

The natural history of electronics /

Gabrys, Jennifer. January 2007 (has links)
No description available.
65

Biconversion of cheese whey into fuels and solvents

Vaca Mier, Mabel. January 1985 (has links)
No description available.
66

The Evolution of a Municipal Solid Waste Disposal System: A Design Case Study

Love, Osborne Raymond 07 1900 (has links)
A record of the design evaluation of a municipal solid waste disposal system has been made. The record was arranged chronologically on a process basis. The author had presented his analyses of the design influences. Emphasis has been put on the major influences. Observations and analyses of a more general nature, plus personal views of the case study method are also given. Recommendations for further study of this project are provided in a test proposal outline for the system. / Thesis / Master of Engineering (ME)
67

An Investigation of Wood and Wood Packaging Waste in the United States

Shiner, Zachary Philip 19 July 2018 (has links)
Each year a large number of wooden pallets are manufactured, recycled, and disposed of during the transportation of goods throughout the United States. The production of these pallets consumes a significant amount of wood and a large number of pallets also end up in landfills at the end of their useful life cycle. However, these pallets can be recovered through repair, broken apart into components, ground into mulch, fuel, animal bedding, or used by landfills for day to day operations. The purpose of this research was to investigate the total number of pallets and crates reaching landfills in the United States as well as to gain a better understanding of the overall waste stream. This was done by surveying all licensed Municipal Solid Waste (MSW) and Construction and Demolition (CandD) landfills in the continental United States. A questionnaire was sent to these landfills, and this entire study was intended to build upon previous Virginia Tech landfill surveys conducted in 1995 and 1998 with some changes made after careful review. Overall, it was found the average MSW facility in the United States received 185,077 tons of waste and the average CandD facility received 74,911 tons. This results in a total national estimate of 253 million tons of MSW and 76.9 million tons of CandD waste. Approximately 18.3 million pallets were landfilled and an additional 13.8 million were recovered, repurposed, or reused at MSW facilities. At CandD facilities, approximately 19.2 million pallets were landfilled while 38.3 million were recovered. / Master of Science
68

A Contrast of the Classical and Institutional Theories of Production and Waste

Burns, Thornton E. 08 1900 (has links)
The purpose of this thesis is to study the writings of two schools of economic thought to bring out the theories of production, resources, and waste of resources involved and compare and contrast them.
69

The regulation of domestic solid waste management in local government : perspectives from the Limpopo Province / Maria Marupeng Malatji

Malatji, Maria Marupeng January 2014 (has links)
In general, the improper disposal of waste may hinder the constitutional guarantee of a right to an environment to human health or well-being. This is especially true of domestic solid waste, a particular area of the waste stream frequently disposed of on South Africa's vacant land, rivers and streets amongst other. There is need therefore for municipalities as locally based authorities that are constitutionally bestowed with specific functions and duties in relation to waste, to ensure effective domestic solid waste management. The aim of this study is to investigate the content and design of some legal instruments aimed at domestic solid waste management in two municipalities of South Africa’s Limpopo Province namely the Lephalale and Greater Tzaneen Municipalities. The investigation and critical analysis of the selected instruments are based on the content of South Africa’s national waste law and policy with respect to domestic solid waste management specifically. The study concludes with a number of observations and recommendations with respect to the investigation instrumentation of Lephalale and Greater Tzaneen Municipalities. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2014
70

The regulation of domestic solid waste management in local government : perspectives from the Limpopo Province / Maria Marupeng Malatji

Malatji, Maria Marupeng January 2014 (has links)
In general, the improper disposal of waste may hinder the constitutional guarantee of a right to an environment to human health or well-being. This is especially true of domestic solid waste, a particular area of the waste stream frequently disposed of on South Africa's vacant land, rivers and streets amongst other. There is need therefore for municipalities as locally based authorities that are constitutionally bestowed with specific functions and duties in relation to waste, to ensure effective domestic solid waste management. The aim of this study is to investigate the content and design of some legal instruments aimed at domestic solid waste management in two municipalities of South Africa’s Limpopo Province namely the Lephalale and Greater Tzaneen Municipalities. The investigation and critical analysis of the selected instruments are based on the content of South Africa’s national waste law and policy with respect to domestic solid waste management specifically. The study concludes with a number of observations and recommendations with respect to the investigation instrumentation of Lephalale and Greater Tzaneen Municipalities. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2014

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