published_or_final_version / Architecture / Master / Master of Landscape Architecture

Scientific evidence of human impact on the natural environment, such as global warming, continues to mount. Green manufacturing systems that focus on minimizing environmental impact of manufacturing processes and products are ever more important to our sustainable future. Green manufacturing systems are slow to gain acceptance as manufacturers are focused on implementing Lean manufacturing systems, generally considered the most competitive manufacturing systems in the world. In recent years, researchers and the US Environmental Protection Agency (EPA) have sought to "build a bridge" between Lean and Green manufacturing systems, in hopes that the rapid expanse of Lean can serve as a catalyst to the implementation of Green manufacturing systems.This study contributes to this growing body of knowledge by determining if leading Lean manufacturers are transcending beyond the traditional limits of Lean and implementing Green manufacturing systems as part of their overallwaste reduction strategy. In this work Lean manufacturing plants that have been evaluated by a panel of experts from the Shingo Prize for Excellence in Manufacturing are surveyed on the diffusion of Green manufacturing system practices throughout their operation. A full system correlation analysis is performed utilizing forty-eight measures of Lean and Green manufacturing systems under the categories of management system, waste reducing techniques, and results. Data analysis indicates that known Lean manufacturers are significantly Greener than the general population of manufacturers in twenty-five of twenty-six measures of Green manufacturing. Lean manufacturers who implement Green manufacturing systems have the strongest results in both Lean and Green result areas, particularly cost reduction, indicating synergy between Lean and Green manufacturing systems. Manufacturing plants that choose to vertically integrate versus horizontally integrate their Lean systems transcend to Green manufacturing. Mexican plants in the study practice significantly higher levels of material resource efficiency and are more inclined to develop industrial partnerships to resolve environmental issues. The study also identifies a critical need for integrating Lean and Green management systems to drive synergistic waste reducing techniques throughout the operation. An integrated Lean and Green manufacturing system model, dubbed "Zero Waste Manufacturing", is proposed as a solution for economically and environmentally sustainable manufacturing.

Through the National Environmental Management Act (No. 107 of 1998), the South African Department of Environmental Affairs and Tourism (DEAT) introduced the concept of the Waste Hierarchy (Reduce - Reuse - Recover - Dispose) as the only possible road towards sustainable development. This concept of sustainable waste management was extended into the Polokwane Declaration on Waste Management which identified Zero Waste as the ultimate goal for sustainable waste management systems in South Africa. Zero Waste is defined as the concept of using all waste produced in a certain area for production activities in that area when it is environmentally acceptable, socially equitable and economically viable, with unavoidable residual waste going to landfill. The aim of this thesis is to test the applicability of Zero Waste to post-consumer waste arising from rural and urban areas. The primary reason that this study has been attempted is that little research in South Africa has focused on the demand-side management of post-consumer waste, and that whatever research that has been undertaken has focused almost exclusively on waste management in urban areas. In order to realise the aim of this thesis, two case studies were selected and analysed: one rural and one urban. These case studies were selected due to differences in characteristics of the waste arising from households, existing waste management systems and socio-economic indicators for households in these areas. In each case study, a proposed Zero Waste Scheme was assessed for application based on four sustainability criteria: environmental, social, economical and institutional. The Zero Waste Schemes are based on the conceptual Zero Waste Model (ZWM) that has been specifically developed as the main tool for conducting this research. The development and use of the ZWM in assessing waste management systems in South Africa is a significant contribution of this thesis to knowledge. Generally, the results showed that the proposed Zero Waste Schemes could meet three of the evaluation criteria used in the investigation, but could not meet the fourth: institutional sustainability. For this reason, the Zero Waste Schemes could not be implemented since the municipalities responsible for waste management in those areas did not have the capacity administrative, financial resources and political will - to implement them. Thus, institutional sustainability has been shown to be the main constraint in the application of Zero Waste Schemes in post-consumer waste management systems in South Africa. This is another significant contribution of this thesis to knowledge.Other significant findings from this study reveal that rural areas lack basic waste collection and disposal systems; hence this lack in service delivery prevents full implementation of Zero Waste Schemes in these areas. In contrast, households in urban areas are served by integrated waste management systems that extend to most households, and most of these households are able to finance the waste management services provided. The existence of the integrated waste management systems was used as a basis for introducing waste minimisation and at-source separation of recyclables in order to reduce the amount of waste needing disposal. Education of households in urban areas has been identified as a key factor in establishing Zero Waste Schemes in the case study areas. In conclusion, it has been shown in this thesis that although Zero Waste Schemes are theoretically applicable to rural and urban areas of South Africa, institutional constraints that will have to be overcome in order to make Zero Waste a reality. Implicit in this conclusion is the extension of waste collection services to rural households and the full participation of rural and urban households in Zero Waste Schemes, participation which can only be verified by actual implementation of the schemes. This is the next step in the approach towards Zero Waste within post-consumer waste management in South Africa. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2009.

Municipal solid waste (MSW) management has been a challenging issue throughout history. Waste management options have evolved, but they can present distinct environmental impacts, such as the emission of greenhouse gases (GHG). This study quantified the environmental benefits (i.e., greenhouse gas emission and energy use reductions) of various MSW management plans proposed for Puerto Rico through the use of the Waste Reduction Model (WARM). The waste management initiative known as the “Base Case” was found to offer the most environmental benefits. Thus, higher benefits can be attained from the implementation of an integrated solid waste management / Department of Natural Resources and Environmental Management

The performance of dry, low NOx gas turbines, which employ lean premixed (or partially premixed) combustors, is often limited by combustor stability. To overcome this issue, a novel design, referred to as a Stagnation Point Reverse Flow (SPRF) combustor, has been recently demonstrated. The SPRF combustor has been shown to produce low NOx emissions with both gaseous and liquid fuels. The objective of this thesis is to elucidate the interactions between the flowfield and combustion processes in this combustor for gas- and liquid-fueled operation. This is achieved with experimental measurements employing various optical diagnostic techniques. These include Particle Image Velocimetry (PIV), chemiluminescence imaging, Planar Laser-Induced Fluorescence (PLIF) of OH radicals and laser scattering from liquid droplets. Velocity measurements in gas-fueled operation show that both nonreacting and reacting flows exhibit a stagnation region with low mean velocity and high turbulence intensities. The high shear between the forward and reverse flows causes significant recirculation resulting in enhanced entrainment and mixing of the returning product gases into the incoming reactant jet for the reacting flow cases, which enables stable operation of the combustor at very lean equivalence ratios. Nonpremixed operation produces a flowfield similar to premixed case except in the near-field region where high turbulence intensities result in significant fuel-air mixing before combustion occurs. Operation of the SPRF combustor with liquid Jet-A is also investigated experimentally. The results indicate that while the overall flow features are similar to the gas-fueled SPRF combustor, the combustion characteristics and NOx performance in liquid operation are strongly controlled by fuel dispersion and evaporation. Injecting the liquid at the exit of the air annulus results in a highly lifted flame, similar to nonpremixed gaseous operation. On the other hand, retracting the fuel injector well inside the air annulus produces a well-dispersed fuel pattern at the reactant inlet leading to a reduction of the equivalence ratio in the fuel consuming reaction zones. Since the effective Dahmkohler number increases with global equivalence ratio, the difference in NOx emissions is more pronounced at higher fuel-air ratios as the retracted injector lowers the relative mixing time compared to the flush case.

Thesis (M.Env.St.)--University of Adelaide, Dept. of Geographical and Environmental Studies, 2000. / Bibliography: leaves 123-130.

Thesis (D.B.A.)--Murdoch University, 2004. / Thesis submitted to the Division of Arts. Bibliography: leaves 264-270.

Thesis (M.Eng.(Engineering and Technology Management))-University of Pretoria, 2007. / Abstract in English. Includes bibliographical references.

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (p. 47-50).

Thesis (MSc)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: There is increasing pressure on factories and government to practise cleaner technology. The public is becoming more and more environmentally aware and external pressure from international competitors is also forcing companies to adopt environmentally sound production practices. Our natural resources and the environment need environmentally friendly practices. Waste minimisation is not only prudent practice for manufacturing industries, but is also an integral part of environmental regulations in many countries, including South Africa. This research seeks to investigate the extent and potential for industrial waste minimisation in Stellenbosch. The objectives of this thesis are, firstly to establish and evaluate the present range and extent of industrial solid waste minimisation practices; secondly to identify and evaluate potential industrial solid waste minimisation measures that could (if necessary) be instituted in future; and finally to propose a general strategy for the minimisation of industrial solid waste in Stellenbosch. The findings reflect that currently there is little waste minimisation awareness and practice in Stellenbosch. The most common method of waste minimisation currently practised by industries is recycling through the selling of recyclables. The least common method is the equipment-related change method, due to the high costs involved in adopting this method. Based on the findings, a suitable regional waste management strategy was developed and this strategy could possibly be adopted elsewhere in South Africa. Key words: waste minimisation, waste management, re-use, recycling, factory, environment, practice, participation, cleaner technology, awareness, Stellenbosch / AFRIKAANSE OPSOMMING: Daar is toenemende druk op fabrieke sowel as op die regering om skoner tegnologie te beoefen. Die publiek raak ook toenemend meer omgewingsbewus en druk vanaf die kant van internasionale mededingers forseer maatskappye om praktyke in te stel wat gunstig is ten optigte van die omgewing. Ons natuurlike hulpbronne en die omgewing benodig omgewingsvriendelike vervaardigingspraktyke. Die beperking van afvalstowwe is nie net vir die fabriekswese 'n wyse praktyk nie, maar maak ook in vele lande, met inbegrip van Suid-Afrika, 'n integrale deel uit van regulasies met betrekking tot die omgewing. Hierdie navorsingsprojek poog om die omvang en potensiaal van beperking van afvalstowwe in Stellenbosch te ondersoek. Die doelwitte van die ondersoek is eertens om ondersoek in te stel na die huidige reikwydte en omvang van praktyke om vaste industriële afvalstowwe te beperk en dit te evalueer; tweedens om potensiële industriële vaste afvalstofbeperkingsmaatreëls wat, indien nodig, in die toekoms ingestel sou kon word, te indentifiseer en te evalueer; en dan uiteindelik 'n algemene strategie vir die beperking van vaste industriële afvalstowwe in Stellenbosch voor te stel. Die bevindings in hierdie tesis bewys dat daar tans gennge bewustheid van die noodaaklikheid van afvalstofbeperking in Stellenbosch is en dat dit ewe min in die praktyk toegepas word. Die mees algemene vorm van beperking van afvalstowwe in die fabriekswese is deur middel van verkoop van herwinbare afvalstowwe. Die mins algemene vorm van beperking van afvalstowwe hou verband met die vervanging van toerusting. Die rede hiervoor het te doen met die koste verbonde aan die strategie. Vanuit hierdie bevindings is toepaslike strategie vir die bestuur van afvalstowwe op streeksvlak ontwikkel. Hierdie strategie sou moontlik ook elders in Suid-Afrika toegepas kon word. Sleutelwoorde: beperking van afvalstowwe, afvalstofbestuur, hergebruik, herwinning, fabriek, omgewing, praktyk, deelname, skoner tegnologie, bewustheid, Stellenbosch