The urban atmospheric environment contains a complex cocktail of pollution from numerous sources. However, the contribution to this mixture from power stations and other high-temperature combustion point sources is uncertain. Spheroidal carbonaceous particles (SCPs) and inorganic ash spheres (IASs) are uniquely formed as a by-product of high-temperature combustion of fossil fuels and therefore are ideal indicators of fossil-fuel derived pollution in London. Deposition of SCPs in London from power stations and other combustion processes regulated by the Environment Agencies under Part A of the Environment Act 1990 was modelled using the atmospheric dispersion modelling system (ADMS 3) developed by the Meteorological Office and the Cambridge Environmental Research Consultancy. The results agreed well with the spatial distribution of SCP concentrations in surface sediments from twenty-seven lakes and ponds within the M25. SCP size distributions were used to identify the dominant sources of SCPs for each site. Multivariate statistical analyses showed that lake and pond processes were generally not important variables affecting the concentration of SCPs in the surface sediments. High resolution SCP and IAS time-series collected by Burkard Spore Traps on a transect linking the centre of London with the power stations in the east Thames Corridor showed the presence of several pollution events, both SCP and IAS, that occurred simultaneously at a number of sites. Potential sources were identified for each IAS and SCP event based on SCP size data and meteorological conditions. The relationship between the IAS and SCP concentrations indicated whether the event was caused by a coal- or oil-fired source. Multivariate statistical analyses of the meteorological data did not consistently extract any one variable that would explain the SCP and IAS profiles. However, a subjective analysis of the data shows that many IAS events in London are caused by emissions from the power stations in the east Thames Corridor.

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Bird populations are changing at unprecedented rates in response to human-induced changes to the global environment, and these rates of change are expected to accelerate over the coming decades. Changes in the levels of sulphur dioxide (SO2) in the atmosphere through emissions from power stations pose a potential threat to bird populations. However, avian response to SO2 pollution is poorly understood. Exploring the relationship between avian diversity and SO2 exposure levels will help in determining species sensitive to air pollution. This study seeks to understand the interactions between avian diversity and SO2 concentration levels around Matimba power station so as to have more insight on the level of avian vulnerability to air pollution. Matimba is an important site in South Africa as a second coal fired power station, Medupi, is currently being constructed with additional stations also a possibility. This study represents an important baseline assessment of the avian population status before the additional pollution burden is realised from Medupi. Ten min repeated point counts were conducted at three sample sites with varying distances from Matimba and Medupi power stations. These counts were used to calculate bird species density and diversity. Cloud-free Landsat 8 imagery acquired on 7 January, 2014 was used to derive habitat structure and productivity variables. Elevation variables were derived using a DEM (Digital Elevation Model) obtained from NASA Global Data Explorer. The AERMOD dispersion model was used to characterise spatio-temporal variations in ambient SO2 concentrations around Matimba power station. Multiple regression analysis was then used to ascertain which of these variables (SO2, habitat structure, productivity and terrain) contribute most to the observed variation in bird species density and diversity around Matimba and Medupi power stations. SO2 polluted air did not have an influence on bird species density and diversity at the community level. At species level two species (Batis molitor and Streptopelia senegalensis) exhibited some measure of negative response to SO2 air pollution. However, after further investigation using multiple regression analysis it was revealed that habitat structure had more influence on the density of these two species compared with ambient SO2 concentrations. Bird species density and diversity varied significantly among the sample sites but were not related to the distance to the source of the SO2 air pollution. Evidence obtained from this study revealed that continuous monitoring of the interactions between SO2 polluted air and bird populations is recommended for a more comprehensive understanding of avian susceptibility towards SO2 air pollution and this will also facilitate in the selection of sensitive and relevant species for future ecology studies at other coal-fired power stations. Furthermore, it is expected that SO2 concentrations will significantly increase with the commissioning of Medupi power station thus further necessitating the need for continuous monitoring of bird species densities around Matimba and Medupi power stations. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2015

Bird populations are changing at unprecedented rates in response to human-induced changes to the global environment, and these rates of change are expected to accelerate over the coming decades. Changes in the levels of sulphur dioxide (SO2) in the atmosphere through emissions from power stations pose a potential threat to bird populations. However, avian response to SO2 pollution is poorly understood. Exploring the relationship between avian diversity and SO2 exposure levels will help in determining species sensitive to air pollution. This study seeks to understand the interactions between avian diversity and SO2 concentration levels around Matimba power station so as to have more insight on the level of avian vulnerability to air pollution. Matimba is an important site in South Africa as a second coal fired power station, Medupi, is currently being constructed with additional stations also a possibility. This study represents an important baseline assessment of the avian population status before the additional pollution burden is realised from Medupi. Ten min repeated point counts were conducted at three sample sites with varying distances from Matimba and Medupi power stations. These counts were used to calculate bird species density and diversity. Cloud-free Landsat 8 imagery acquired on 7 January, 2014 was used to derive habitat structure and productivity variables. Elevation variables were derived using a DEM (Digital Elevation Model) obtained from NASA Global Data Explorer. The AERMOD dispersion model was used to characterise spatio-temporal variations in ambient SO2 concentrations around Matimba power station. Multiple regression analysis was then used to ascertain which of these variables (SO2, habitat structure, productivity and terrain) contribute most to the observed variation in bird species density and diversity around Matimba and Medupi power stations. SO2 polluted air did not have an influence on bird species density and diversity at the community level. At species level two species (Batis molitor and Streptopelia senegalensis) exhibited some measure of negative response to SO2 air pollution. However, after further investigation using multiple regression analysis it was revealed that habitat structure had more influence on the density of these two species compared with ambient SO2 concentrations. Bird species density and diversity varied significantly among the sample sites but were not related to the distance to the source of the SO2 air pollution. Evidence obtained from this study revealed that continuous monitoring of the interactions between SO2 polluted air and bird populations is recommended for a more comprehensive understanding of avian susceptibility towards SO2 air pollution and this will also facilitate in the selection of sensitive and relevant species for future ecology studies at other coal-fired power stations. Furthermore, it is expected that SO2 concentrations will significantly increase with the commissioning of Medupi power station thus further necessitating the need for continuous monitoring of bird species densities around Matimba and Medupi power stations. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2015

>Magister Scientiae - MSc / Coal-fired power stations produce large volumes of coal combustion residues (CCRs), which are disposed of in hold ponds or landfill sites. These ash storage facilities are limited in space and are approaching the end of their capacities, thus additional land is required for extensions. If new land is not sourced, power plants will be forced to cease operations, resulting in increased expenditure costs and environmental liability. A proposed disposal solution is to backfill opencast coal mines with CCR monoliths. However, there is limited knowledge on the hydraulic behaviour of CCRs in an opencast coal mine environment. This leads to an inability to assess this applications feasibility and determine whether this activity will have a positive, negligible or negative effect on groundwater quality. This study aims to address this gap in knowledge by assessing the flow and transport properties of CCRs under numerous theoretical backfilling conditions.