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Two complex wastes were considered for biological conversion into a marketable product. One waste, peat runoff water (the waste-water that remains after the mining of peat), was found to be unsuitable for biological conversion to any product since it contained an insufficient quantity of carbon. The other waste, NVR (non-volatile residue, the major waste from the manufacture of nylon 6$ sp prime 6 sp prime$), was found to be a suitable carbon and energy source for the production of PHB (poly-$ beta$-hydroxybutyric acid) by Pseudomonas cepacia ATCC 17697. A general approach to the development of complex toxic wastes as fermentation substrates was formulated. / NVR was found to be toxic to microorganisms. None grew in enrichment culture containing 2.0% NVR. P. cepacia was the most resistant microorganism found. It could grow well in up to 1.3% NVR. It also grew on butanoic, pentanoic, and hexanoic acid as well as 6-hexanolactone. These were found to be the major toxic components of NVR. P. cepacia was grown in a NVR-limited chemostat with a NVR feed concentration well in excess of the toxic NVR concentration. In nitrogen-limited, batch fermentation on fructose, P. cepacia accumulated PHB in excess of 50% of its dry weight. A 2-stage chemostat process for the production of PHB from NVR by P. cepacia was investigated with encouraging results.

This thesis examines the regional electronic and electrical waste (e-waste) recycling network in Malaysia and Singapore, with a secondary focus on the articulations of informal labour within the network. I argue that there is a need to theorise production networks post-consumption; i.e. to focus on the activities and processes that occur after a commodity is consumed and subsequently discarded. I argue that discarded e-waste are not ‘value-less’ waste, but instead embody value (specifically latent use value), and have the potential to be re-inserted as ‘raw materials’ into production networks through the processes of recycling. Also, key to the processes of value (re)creation, enhancement and capture is the labour process. I examine informal labour by focusing on karung guni (a local term for the rag-and-bone man) – analysing their critical role in value (re)creation in this regional e-waste recycling production network through the lens of petty commodity production. I argue that karung guni are constitutive of this production network through their collection and primary processing of e-waste, which forms the basis for subsequent value creation, enhancement and capture by downstream actors. Conceptualising karung guni as petty commodity producers – who own both the means of production and their own labour power – is significant in problematising as not so straightforward the separation of capital and labour into discreet categories as normally presented in global value chains (GVC)/global production networks (GPN) approaches. This thesis makes four significant contributions to the GVC/GPN literature. First, it recognises activities beyond the point of consumption (which has been the focus of present GVC/GPN research). Second, it conceptualises the constitutive role of informal labour in the development and structure of production networks. Third, it emphasises the continued relevance of the state. Fourth, by adopting a multi-sited case study method, it contributes to debates on how to carry out GVC/GPN research.

M. Tech. Textile Design and Technology / Scientific research shows that the earth's natural resources are being depleted too fast for it to sustain a healthy balance, while global warming and pollution prove to be increasing problems for the environment. By re-using and recycling waste, natural resources are conserved while waste is prevented or delayed from being dumped or incinerated. Globally textile waste could be viewed as an untapped source. In some developed countries, up to ninety five percent of textiles that are land-filled, have the potential to be recycled. The process of textile recycling has the potential to reduce textile waste through creating marketable products from recycled waste. The aim of this research is to create better understanding regarding the reusable potential of textile waste by developing marketable strategies that can be implemented with regard to textile waste.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

An annular control valve was developed for the extrusion of wood slurries and polymers. The objective was to determine the optimal valve geometry: (1) to provide a linear pressure drop across the valve as a function of valve opening and (2) to eliminate the problem of valve plugging caused by the high solid content of the wood slurries. The approach was to model the non-Newtonian flow in a plasticating single-screw extruder. A finite-difference scheme was developed to model the flow through annular surfaces. The two flow equations were solved simultaneously and a parametric study was performed to determine the optimal valve geometry. The valve operability was evaluated for the extrusion of various mixtures of low-density polyethylene, sawdust, wood flour, and vacuum bottom. The experimental results were in good agreement with the model. In general, a linear valve characteristic was observed and the problem of valve plugging was not evident.

This thesis examines the relationships people have with rubbish in everyday life. Focusing on domestic recycling policy and practice, environmental concern and action is explored as a sociological problem in a way that moves beyond the individualising paradigms that dominate environmental discourse for behavioural change. In its place, this thesis argues that better explanation may reside in the social context of embedded practices, and how they get enacted in daily life. Beginning with a historical overview and evaluation of current policy, this thesis re-imagines domestic recycling as a complex socio-technical system involving the engagement of different actors. Conducted at the boundaries of sociology, this thesis draws on empirical and theoretical ideas that extend across disciplines. Methodologically the research has been grounded on a principle of mixed methods pragmatism, exploiting the Sequential Explanatory mixed methods research design. Conducted across two phases, Phase One involved the secondary analysis of the Scottish Household Survey and Phase Two the collection and analysis of qualitative data using the Diary- Interview method. The first phase was a macro- analysis of recycling practices in Scotland. The main results of this analysis are presented in Chapter 4, which built a Binary Logistic Regression model, using the Scottish Household Survey, to predict the characteristics of Scottish households likely to engage in recycling behaviour. In addition to identifying the social and structural dimensions of recycling in Scotland, this analysis also enabled a research site to be selected for Phase Two of the study. Chapters 5 and 6 respond to the macro- analysis by accounting for the micro- aspects of recycling practices by looking at the problem inductively. Using qualitative data analysed in Phase Two, these two chapters are based on the idea that how people value the environment is relevant for understanding contemporary recycling practices. Chapter 5 considers the explanatory usefulness of environmental ethics, values and citizenship for explaining why some households engage in environmental behaviour, but others do not. In Chapter 6 these arguments are developed further with a more detailed discussion about how household recycling practices get enacted in everyday life. Using evidence from the data, this chapter considers why commitment to ‘doing’ recycling varies between people and examines recycling as formed, cultivated and maintained habitual behaviour. Taken together the three data chapters try to show that, rather than be an inconsequential feature of normal domestic life, recycling is a practice deeply-rooted in wider social patterns and structural forces. In the final chapter, all of the micro- and macro- findings are integrated together and concluded, along with some reflections on the multidimensionality of contemporary recycling practices in the home, and what this might mean for policy and future research.

published_or_final_version / Architecture / Master / Master of Landscape Architecture

Electrical and electronic goods production is one of the fastest growing markets in the world. More new electronic goods appear every year. If the electronic waste cannot be managed and recycled properly, more and more electrical and electronic waste (WEEE) would be generated in the future. In fact, improper WEEE treatment causes tremendous harmful effect to the environment and finally affects our health. More effort was put in WEEE recycling worldwide. In recent years, the government, NGOs and other responsible parties worked very hard in Hong Kong WEEE recycling. However, Hong Kong is still lagging behind in terms of WEEE recycling compare with other countries. In Hong Kong, large quantities of WEEE are shipped to developing countries, which are non-ethical. Some of them would also go to landfills in Hong Kong, which causes serious land contamination. Even if the electronic waste is collected, the collectors may not follow the EPD guidelines to recycle the waste. Therefore, it is important to let people know the environmental impact of WEEE, the proper WEEE recycling channels and the importance of WEEE recycling so as to raise their awareness towards WEEE issues. There are few research findings about household WEEE recycling in Hong Kong, especially the household attitude and behavior towards WEEE recycling. The result in this dissertation can fill this knowledge gap. In this study, questionnaires will be used to find out the WEEE generation pattern and recycling frequency in households, the prefer disposal methods for household WEEE and the household attitudes and behavior towards WEEE recycling. Besides, some WEEE recycling facilities will be visited to identify difficulties in WEEE recycling. Finally, possible ways will be suggested to tackle the difficulties of WEEE recycling. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management