Coal surface mining in the Appalachian USA coalfields can lead to significant environmental impacts including elevated total dissolved solids (TDS) levels in receiving streams. Column leaching procedures are recommended by many studies for TDS prediction, but many question their applicability to field conditions. The objective of this study was to assess results from a simple column leaching method relative to larger scale leaching vessels (scales) using one coal mine spoil and two coarse coal refuse materials. A non-acidic mine spoil sample from SW Virginia (crushed to ≤ 1.25 cm) was placed into PVC columns (~10 cm x 40 cm) in the laboratory and leached unsaturated with simulated acidic rainfall. The same spoil was also placed into larger 'mesocosms' (~1.5 m³) with run-of-mine material and into barrels (~0.1 m³; screened to ≤ 15 cm) under natural field environmental and leaching conditions. Similarly, two coarse coal refuse samples were placed into lab columns and field barrels. Comparative results suggest the column method was a reasonable predictor of TDS release from the coal mine spoil relative to the two larger scales studied. However, there were significant differences at times during the study, including during initial peak TDS elution (1,750 µS cm⁻¹ in columns vs. 2,250 µS cm⁻¹ in mesocosms). Field leaching also produced a distinct seasonal time-lagged EC pattern that was not observed in the columns. On the other hand, significantly different and dissimilar leaching results were noted for the refuse column vs. barrel leachates, calling into question their prediction ability for refuse. / Master of Science

For many aggregate mining facilities, the stockpile is the preferred method of storing rock. In many aggregate mines, as well as other mines using stockpiling techniques, understanding the timing and flow of particles through a stockpile is important for correctly timing samples, making proper process adjustments and overall stockpile safety. Because much of the research of today lacks important information regarding actual interior particle movement within a stockpile, a series of Real Time Distribution (RTD) analyses and stockpile flow models have been prepared and analyzed for this study in order to better understand the flow characteristics of a stockpile. A series of three RTD analyses performed on three separate stockpiles provides information leading to the assumption that stockpiles tend to operate similar to a plug flow system. While conveyor loading techniques may lead to separation of rocks prior to traveling through the stockpile, the majority of the rock particles entering the pile remain near the point of entry, or within the "action" area, and will travel through the pile in a plug flow, rather than a mixed flow, manner. High Peclet number results for each analysis prove this assumption to be accurate. A series of models on three separate stockpiles have been created using PFC3d. Mainly, the simulations prove PFC3d is capable of showing how stockpile particles move in three dimensions while monitoring specific particles within the pile. In addition, these models provide simulation results similar to the results obtained within the RTD analyses. Results show that particles located directly above the discharge point, or "action" area, travel through the pile at a faster rate than particles surrounding this area. Velocity results obtained from the simulations show particles accelerating as they get closer to the discharge points while also providing evidence of "arching" during the simulation process. These findings provide a better understanding of internal flow within the stockpile and ways to possibly predict future stockpile flow issues that may be encountered. / Master of Science

This work includes two different areas of research. Both areas are related to the combustion of the binder-enhanced densified refuse derived fuel (bdRDF) with high sulfur coal and examining trace elements. The first area of this work involved studying the trace metals in the combustion gas of bdRDF/coal blend and the effect of the binder, CA(OH)2, on reducing the trace elements emissions. The second area of work involved studying the trace elements in the fly ash and the effect of the dRDF and the binder of trace metals.

The aim of this study was to explore the role of environmental education in dealing with solid waste in the Central Business District of Thohoyandou. The study was carried out in the Thohoyandou Central Business District (CBD). Two organisations were identified as practising environmental education in Thohoyandou, namely, the Environmental Education Desk (Environmental Affairs) and the Environmental Health Services (Thulamela Municipality). Officers from these organisations were interviewed. Vendors and hawkers in the Thohoyandou Central Business District were asked to complete a questionnaire on the role of environmental education in dealing with solid waste. The literature review in the study included the theoretical perspectives on environmental education and solid waste. From this review that solid waste can have both a positive and negative impact on the local and global environment. Therefore, environmental education that has a role in dealing with solid waste has an important part to play in sustainable development. / Educational Studies / M.Ed.(Environmental Education)

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

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

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

published_or_final_version / Public Administration / Master / Master of Public Administration

Few environmental problems exemplify market-failure better than municipal solid waste does: A direct by-product of economic production and consumption, its collection and disposal (still mainly at landfills, in many countries) incurs high capital and running costs, creates environmental and health impacts and, in European Union countries, risks incurring heavy financial penalties. The main remedy proposed in environmental economics is a marginal tax on the disposal of mixed household waste, intended to incentivise its reduction and separation for recycling. But taxes are politically unpopular, expensive to administer and generate variable response − sometimes stimulating illegal disposal of waste instead of its reduction. Taxes also risk undermining the moral benefits people seem to enjoy from cooperating voluntarily. Inducing voluntary cooperation could cultivate moral motives and generate cooperation, but this has received less attention in environmental economics to date. The aim of this thesis is to examine the determinants of cooperation by households in waste management activities, investigating the role that government policy can play in stimulating it, and focusing on the role of price incentives and of scheme promotion. Chapter 1 introduces the issue of waste management as an economic problem, and the role of household cooperation as a promising solution. Chapter 2 surveys the literature on the topic of what determines household cooperation in waste management and identifies the key gaps which the thesis seeks to address. Three manuscripts are presented in Chapters 3, 4 and 5, each of which examines a distinct question on the determinants of household cooperation in waste management. Chapter 6 concludes with a synthesis of main findings, key policy cues and suggestions for future research. The first manuscript titled “Voluntary recycling despite financial disincentives” employs a unique merged panel data set (n = 4,644) using data from 58 localities over 86 weeks to assess the determinants of participation in a voluntary waste separation scheme in Malta. The two manuscripts that follow are based on a nationally-representative telephone survey (n = 1,037), containing two embedded experiments, and conducted during 2013, in Malta, for this thesis. Manuscript 2 titled “Partisanship, priming and participation in voluntary recycling” tests whether party identification, as distinct from environmental or political ideology, can act as a determinant of participation in a recycling scheme, particularly if the scheme is promoted in a manner that associates it with the party in government. Manuscript 3 titled “The impact of a Pay as You Throw tax level and label on home-composting” examines the potential of a Pay As You Throw (PAYT) tax, and of its labelling, to induce substitution of biodegradable waste away from mixed kerb-side disposal and into home-composting. It also examines the prospect that this type of intervention stimulates illegal disposal. Synthesising the results of three studies, the thesis finds that: 1. The type of households most likely to cooperate in waste management schemes are multiple-person ones facing lower constraints of space and time, where members hold pro-environmental preferences. This confirms findings of similar studies in other contexts, helps forecast uptake and may guide the design and promotion of schemes to target low-lying fruit and tackle relevant constraints. 2. Driven mainly by moral motives, households are willing to recycle voluntarily even if it is less convenientc e than disposing of un-separated waste, and they are willing to pay for it. This is a useful finding for municipalities with low budgets, unable to institute taxes or fearing illegal disposal as a reaction. 3. Political preferences are relevant to recycling: Where negative sentiment towards the party in government exists, (even subtle cues) promoting the scheme as a government scheme and associating it with the party in government can suppress participation. Decoupling political communication from scheme promotion can release more households into cooperative effort. 4. Responses to waste taxes are not just a matter of price level but also of tax salience: A tax label can significantly increase waste separation and home-composting but it also boosts higher illegal-disposal intent. The way a fee is labelled therefore itself forms part of the intervention tool-kit, meriting pre-testing and capable of manipulation. These findings make a marginal contribution to gaps in the environmental economics literature by integrating insights from psychology. They are also intended to offer simple and applicable ideas to policy-makers and to scheme-operators aiming to increase household cooperation in waste management.

Ph.D. (Economics) / Street waste pickers are a visible group of people trying to survive under poor socio-economic conditions. They participate in the informal economy as self-employed entrepreneurs. Despite the income-earning opportunity generated by the waste that is freely available, their social and economic conditions remain poor. This study is the first national study to investigate the social and economic conditions of the street waste pickers in South Africa. The national study covers thirteen major cities in South Africa and uses a mixed method research design. A literature review on informal waste picking activities and the participation of the poor in these activities provide a basis from which the socio-economic conditions of the street waste pickers could be analysed. A theoretical overview of poverty theories, the unemployment problem, and the characteristics of the informal economy and informal recycling activities help to contextualise the street waste pickers in terms of the link that exists between poverty, unemployment, and street waste picking activities as a marginal form of informal self-employment. With this as background, qualitative and quantitative data on the socio-economic conditions of the street waste pickers was collected from the street waste pickers themselves and from the buy-back centres with whom they interact on an almost daily basis.