Against a background of a chemical engineering degree and a few years of industrial experience, I undertook this M.Sc. degree with the conviction that chemical engineering skills have a unique role to play in addressing environmental problems of pollution generated by industrial activity. Moreover, given that, of industrial activity, it is chemical processing industries (CPI) and mining industries which are the major contributors to generation of waste, hazardous waste in particular, it is appropriate that the chemical engineering profession, which populates such industry activities, should assume such responsibility. In response to increasingly vociferous demands for more stringent environmental control over industrial activity, and regulatory compliance with stricter constraints on emissions of pollutants, there is a tendency to rely on readily available end-of-pipe solutions to resolve environmental management problems. This strategy is embodied in current practices in South Africa at effluent treatment- and landfill disposal facilities. Yet this is a costly solution in the long term, with implications for increasing operating costs, investment costs for development of new facilities, as well as closure and potential liability costs for old facilities. Furthermore, this strategy fails to address problems of resource depletion and the potential for resource recovery from materials considered to be "waste". Waste minimisation offers an alternative waste management strategy which seeks to reduce the generation of waste before end-of-pipe management is required, and to recover resources for reuse, thereby reducing resource consumption. The Department of Environment Affairs in the South African government has recommended that there should be research in the application of waste minimisation. While clearly there is a need for fundamental research into particular technological problems (such research is being undertaken at some institutions), the approach I adopted was to investigate potential for effecting meaningful waste minimisation solutions using procedures and techniques which constitute popular waste minimisation assessment methodologies. I focused specifically on small and medium scale industry operators which traditionally do not employ chemical engineering skills and which need a practical tool to improve in-house environmental management capability.

In 2010 the city of Cape Town partnered with the Department of Environmental Affairs to initiate a project to investigate and evaluate the possible re-opening and licensing of Historic and Old landfill sites. The project to reassess these landfill sites is due to the fact that the three main operating landfill sites in Cape Town are nearing capacity. This calls for the city to re-imagine its waste management infrastructure. Meanwhile, within the urban areas of Cape Town, there exists a network and constellations of informal waste pickers working in conjunction with buy-back centres and recyclers to form an economically, environmentally and socially sustainable solution that diverts volumes of recyclable waste from landfills. These informal waste pickers contribute to filling in a gap within the formal recycling system but there is no infrastructure supporting these individuals on whom the formal recycling industry depends on. Most of the waste pickers sleep 'on the streets' with little access to amenities such as water, toilets and washing facilities. The spaces they occupy/sleep make it hard to store their pickings and hence they are forced to sell as soon as they collect. It also forces them to make multiple trips to the buy-back centres whom they are always at the mercy of, particularly when the ever changing price of recyclable waste is low. This project aims at creating a productive landscape that uses waste as a vehicle to enhance the livelihoods of informal waste pickers and encourage local communities to see the economic and environmental value of recycling waste. By providing secure storage and sorting, safe/hygienic sleeping and cleaning spaces coupled with social and productive areas; the project seeks to unlock the potential of recycling using a suitable architectural intervention that is self-sustaining.

Thesis (Ph. D.)--Fletcher School of Law and Diplomacy, 1991. / VIta. Includes bibliographical references (leaves 220-231.).

The Institute of REsource Ecology (IRE) is one of the eight institutes of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). The research activities are mainly integrated into the program “Nuclear Waste Management, Safety and Radiation Research (NUSAFE)” of the Helmholtz Association (HGF) and focused on the topics “Safety of Nuclear Waste Disposal” and “Safety Research for Nuclear Reactors”. Additionally, various activities have been started investigating chemical and environmental aspects of processing and recycling of strategic metals, namely rare earth elements. These activities are located in the HGF program “Energy Efficiency, Materials and Resources (EMR)”. Thus, all scientific work of the IRE belongs to the research field “Energy” of the HGF. The research objective is the protection of humans and the environment from hazards caused by pollutants resulting from technical processes that produce energy and raw materials. Treating technology and ecology as a unity is the major scientific challenge in assuring the safety of technical processes and gaining their public acceptance. We investigate the ecological risks ensued by radioactive and non-radioactive metals in the context of nuclear waste disposal, the production of energy in nuclear power plants and in processes along the value chain of metalliferous raw materials. A common goal is to generate better understanding about the dominating processes essential for metal mobilization and immobilization on the molecular level by using advanced spectroscopic methods. This in turn enables us to assess the macroscopic phenomena, including models, codes and data for predictive calculations, which determine the transport and distribution of contaminants in the environment.

No description available.

No description available.

No description available.

No description available.

A safe treatment and disposal of spent Tri-Structural Isotropic (TRISO) coated fuel particles is one of the most important issues for developing the next generation of nuclear reactors, such as a Very High Temperature Reactor (VHTR). The project investigates the encapsulation of surrogated TRISO particles in Glass-Graphite Composite (GGC) and in Alumina Borosilicate Glass (ALBG) and compares their geological performance in the repository. The study deals with the assessment and performance of both matrices in a geological repository's conditions, measuring their chemical durability for 28 days at temperatures ranging 25-90°C and using American Standard for Testing Material (ASTM-C1220-98). The leach test revealed that only sintered ALBG with TRISO particles doped in cesium oxide could provide a safe Engineering Barrier System (EBS). The thermal property of the matrices was examined by measuring their thermal diffusivities. The thermal diffusivity of ALBG bearing various proportions of TRISO particles was measured experimentally using Laser Flash Analysis (LFA). The experimental results validated through a numerical method using Image Based Modelling (IBM). The effect of the porosity in decreasing the thermal diffusivity of TRISO particles was also discussed. In addition, the study deals with the immobilisation of ion exchange resins (doped with radioactive and non-radioactive cesium and cobalt) in borosilicate glass. The thermal analysis revealed that a successful immobilisation could be achieved once the sulfur functional group in the resin was decomposed and evaporated in a form of SO2/SO. The minimum required temperature of the heat treatment was 500°C under air environment as a pre-conditioning stage before immobilisation.

Most prawns are prepared as frozen or canned meat and the remaining waste is used as a feed supplement or directly disposed on to the land, which affects the environment. Fresh prawn bio-waste contains protein, astaxanthin, flavor compounds and chitin. The use of chitin in various applications is limited due to its water insolubility. In this research, a new method is developed to prepare water-soluble colloidal chitin (WSCC) from prawn waste. WSCC having the percentage of degree of deacetylation same with that of chitin follows non-newtonian shear thinning behaviour. The characteristic study showed that the breakage of polymer chains during processing thus reduced the molecular weight and bulk density of WSCC. Therefore, functional properties of WSCC can be controlled by optimizing the processing conditions. Astaxanthin complex has attracted considerable interest in relation to its health benefits because of its powerful antioxidant activity. Traditional extraction of astaxanthin complex from prawn waste using organic solvents requires post-purification steps, creates solvent disposal problem and degrades the pigment. This research develops an efficient way of recovering astaxanthin complex from prawn waste that eliminates the problems associated with solvent extraction methods and offers possible recyclability of the solvents used. Post-harvest blackening in prawns adversely affects both quality and consumer acceptability. However, consumer safety over the chemicals, especially sulphites used in inhibiting prawn blackening is of a major concern. This study shows that the antioxidant, astaxanthin complex can inhibit the poly phenol oxidase (PPO) catalyzed blackening reaction in prawns. Although prawns have astaxanthin complex present in their natural state, its concentration in vivo may not be sufficient to act against PPO. Therefore, astaxanthin complex-enriched feed in prawn culture may prevent prawn melanosis and may eliminate the post-harvest handling methods.