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dc.contributor.advisorBeukes, Johan Paul
dc.contributor.advisorVan Zyl, Pieter Gideon
dc.contributor.authorChiloane, Euphinia Kgaugelo
dc.date.accessioned2019-11-05T12:22:45Z
dc.date.available2019-11-05T12:22:45Z
dc.date.issued2019
dc.identifier.urihttp://orcid.org/0000-0003-3504-3046
dc.identifier.urihttp://hdl.handle.net/10394/33532
dc.descriptionPhD (Environmental Sciences), North-West University, Potchefstroom Campus, 2019.en_US
dc.description.abstractAfter carbon dioxide (CO2), aerosol black carbon (BC) is considered to be the second most important contributor to global warming. Africa is one of the least studied continents, although it is regarded as the largest source region of atmospheric BC. Southern Africa is an important sub-source region, with savannah and grassland fires likely to contribute to elevated BC mass concentration levels. South Africa is the economic and industrial hub of southern Africa with large anthropogenic point sources. To date, little BC mass concentration data have been presented for South Africa in the peer-reviewed public domain. This thesis presents equivalent black carbon (eBC) (derived from an optical absorption method) data collected from three sites, where continuous measurements were conducted, i.e. Elandsfontein (EL), Welgegund (WG) and Marikana (MA), as well as elemental carbon (EC) (determined by evolved carbon method) at five sites where samples were collected once a month on a filter and analysed off-line, i.e. Louis Trichardt (LT), Skukuza (SK), Vaal Triangle (VT), Amersfoort (AM) and Botsalano (BS). All these sites are located in the interior of South Africa. Analyses of eBC and EC spatial mass concentration patterns across the eight sites indicate that the mass concentrations in the South African interior are in general higher than what has been reported for the developed world, and that different sources are likely to influence different sites. The mean eBC or EC mass concentrations for the background sites (WG, LT, SK, BS) and sites influenced by industrial activities and/or nearby settlements (EL, MA, VT and AM) ranged between 0.7 and 1.1, and 1.3 and 1.4 μgm-3, respectively. Similar seasonal patterns were observed at all three sites where continuous measurement data were collected (EL, MA and WG), with the highest eBC mass concentrations measured from June to October, indicating contributions from household combustion in the cold winter months (June-August), as well as savannah and grassland fires during the dry season (May to mid-October). Diurnal patterns of eBC at EL, MA and WG indicated maximum concentrations in the early mornings and late evenings, and minima during daytime. From these patterns, it could be deduced that for MA and WG, household combustion as well as savannah and grassland fires were the most significant sources, respectively. Possible contributing sources were explored in greater detail for EL, with five main sources being identified as coal-fired power stations, pyrometallurgical smelters, traffic, household combustion, as well as savannah and grassland fires. Industries in the Mpumalanga Highveld are often blamed for all forms of pollution in the area due to the NO2 hotspot located in this area, which is attributed to NOx emissions from industries and vehicle emissions from the Johannesburg-Pretoria megacity. However, a comparison of source strengths indicated that household combustion, and savannah and grassland fires were the most significant sources of eBC, particularly during winter and spring months, while coal-fired power stations, pyro-metallurgical smelters and traffic contribute to eBC mass concentration levels all year rounden_US
dc.description.sponsorshipSixth Framework Programme (European Commission) National Research Foundation (NRF) University of the Witwatersrand Helsingin yliopisto Eskom Sasol Ilmatieteen laitosen_US
dc.language.isoenen_US
dc.publisherNorth-West University (South Africa). Potchefstroom Campusen_US
dc.subjectAerosolsen_US
dc.subjectEquivalent black carbon (eBC)en_US
dc.subjectTemporal and diurnalen_US
dc.subjectSource strengthsen_US
dc.subjectCombustionen_US
dc.titleSpatial, temporal and source contribution assessments of aerosol black carbon over the northern interior of South Africaen_US
dc.typeThesisen_US
dc.description.thesistypeDoctoralen_US
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