No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

This thesis presents work relating to the synthesis, structure and stability of various arsenate phases having potential to immobilise high concentration arsenic wastes. Such wastes arise from mining and hydrometallurgy operations and the high arsenic concentrations, arising in tailings dams for example, represent an environmental concern. Large quantities of highly contaminated waste sludge are also generated by the co-precipitations of arsenic on ferric hydroxide floccs from low arsenic concentration waste streams. The disposal of this waste is becoming a prominent issue when cleaning minesite run off and drinking water. It is important therefore to consider the environmental impact of discarded arsenic residues and this project addresses the potential for its immobilisation in low stability minerals capable of return to mine sites. Two groups of phases with the potential for immobilisation of arsenic and other toxic metals are studied in this thesis. The first group are zinc arsenate zeolite analogues. These open framework structures also present the possibility of immobilization of other waste materials by ion exchange. The second group are a series of cadmium arsenate phases, which offer the potential for cadmium and arsenic immobilisation. This thesis examines the crystal structure, and synthesis of both groups of phases and examines their solubility and stability thus assessing their potential as waste immobilisation tools. The results of these studies has shown that although it is possible to make phases which are entirely composed of waste metals these phases are not stable enough for direct use in waste immobilisation processes. The crystal structures of several previously unpublished phases have been determined and a solubility product has been calculated for one of the phases.

No description available.

Urban sprawl, global warming and overused landfills are conditions around the world today, and while people are concerned about these issues they have few practical solutions to them. This creative project seeks to devise a way for a specific sector of business (restaurants), to have a practical way to help reduce global warming and waste while utilizing unused or under-used land in urban areas. While life cycle models are available that address such issues as these, very few case examples are actually in use in this country. Based on existing life cycle models, this project will seek to reuse the wastes from a restaurant and recycle them into a garden/greenhouse (called an urban farm throughout this paper) which will produce food for the restaurant. The three main waste categories from the restaurant to be looked at are the organic kitchen food wastes, water and the heat that is always being expelled from the kitchen while it is operation. Additional ways to make a restaurant more sustainable will also be given. This project will show what the benefits are when a sustainable system is in operation. / Department of Landscape Architecture