Air pollution study of a Highveld township during a Basa njengo Magogo rollout
- Authors: Nuwarinda, Henry
- Date: 2010-05-27T06:06:30Z
- Subjects: Air pollution measurement , Air quality measurement , Coal combustion , Basa njengo Magogo
- Type: Thesis (M. Sc.)
- Identifier: uj:6847 , http://hdl.handle.net/10210/3279
- Description: M.Sc. , Emissions from domestic coal combustion account for high levels of atmospheric particulate concentrations in Highveld townships in South Africa. These levels frequently exceed air quality standards. To reduce these concentrations, a rollout of the “top-down” fire lighting method, also referred to as the Basa njengo Magogo method, was introduced in a Highveld township in Witbank, Mpumalanga, targeting 10,000 households for the winter of 2006. The aims of this study include measuring any reduction in ambient air pollution – specifically particulate matter (PM10) – resulting from reduced emissions due to the rollout of Basa njengo Magogo, and to establish relationships between air pollutants and meteorological parameters. The hypothesis of the study was that the introduction of Basa njengo Magogo would result in a measurable reduction of ambient pollutants, specifically PM10. Continuous measurements were made at intervals of 5 minutes from 12 July to 21 July 2006: ambient concentrations of particulate matter carbon monoxide, carbon dioxide, sulphur dioxide, nitrogen dioxide and hydrogen dioxide were measured as well as meteorological parameters. Due to several factors, specifically the short period of valid measurements, this study was not able to observe a clear reduction signal of particulate matter derived from domestic coal burning. The air quality in the township was characterised, looking specifically at the relationship between meteorological factors and the accumulation and dispersion of pollutants. Investigation of diurnal variations H₂S show that minor components of H₂S are associated with domestic coal combustion, while a source external to Vosman township results in episodes of high H₂S concentrations. These episodes occurred between 04h00 to 07h00 and were associated with light breezes from the sector 170° to 180°. This is the first set of quantitative measurements of H₂S in a Highveld township, and the first source apportionment of H₂S in a Highveld township.
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Optimising the imbaula stove
- Authors: Kimemia, D.K. , Annegarn, H.J. , Robinson, J. , Pemberton-Pigott, C. , Molapo, V.
- Date: 2011
- Subjects: Imbaula stoves , Domestic stoves , Fuel combustion , Stove ignition , Basa njengo Magogo
- Type: Article
- Identifier: uj:6238 , http://hdl.handle.net/10210/8179
- Description: In South Africa, human and environmental health implications from domestic solid fuel combustion have spurred interest in cleaner alternative sources of energy and better combustion technologies. Field research among wood and coal burning informal settlements in Johannesburg has shown that the most prevalent mode of combustion is self-made imbaula (brazier) stoves, manufactured from discarded 20 L steel drums. Such stoves are made without any measure of performance optimisation, leading to fuel inefficiency and high emissions - previous field surveys have indicated that the number, size and placement of primary and secondary air inlets (taken as holes below and above the fire grate respectively) vary over a wide range, starting from an extreme with no holes below the grate . Researchers at SeTAR Centre, University of Johannesburg, have set out to develop an enhanced imbaula, by investigating performance in terms of size and distribution of primary and secondary air inlets, and height of grate level. The test imbaulas are constructed out of standard 20 L drums with a height of 360 mm and diameter of 295 mm. A range of hole configurations has been designed, from which selected test configurations are fabricated for experimental evaluation of thermal and emissions properties, using the SeTAR heterogeneous testing protocol. The results indicate that higher hole densities (above and below the grate) lead to higher power outputs and lower specific CO emissions, but with lower thermal efficiency. Further, results indicate that adequate air holes below the grate (primary air) are more important for proper combustion in an imbaula; however this should be synchronised with secondary air in-lets (above the grid) in order to have congruence of all the performance criteria. This study should lead to the development of a set of criteria that can further enhance emissions reductions and fuel efficiency obtained by top-down stove ignition methods (Basa njengo Magogo) for imbaula type stoves.
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