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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characterisation of some fractured-rock aquifers in Limpopo province, South Africa : review and case study

Dippenaar, Matthys Alois 13 October 2009 (has links)
This dissertation collates all available data from the Department of Water Affairs and Forestry’s (DWAF’s) National Groundwater Database (NGDB), DWAF’s Groundwater Resource Information Project (GRIP) and tests conducted during the progress of this project in order to evaluate Basement aquifers. The project was commenced at the request of the Water Research Commission (WRC), situated in Pretoria, South Africa. The study area (Limpopo and Luvuvhu-Letaba Water Management Areas, WMA1 and WMA2 respectively) is underlain by fractured, crystalline Basement terrain. The influences of structures (i.e. joints, faults and shear zones) and the neotectonic stress conditions were also studied to address the influence on groundwater flow and occurrence. The aim of the project was to address the determination of the aquifer parameters (essentially transmissivity and sustainable yield) in Basement terrane. Pumping test data was used and analysed via the Flow Characteristic Programme (Institute for Groundwater Studies, University of Free State). The methods of Logan (1964), Theis (1935), Cooper-Jacob (1946) and Birsoy-Summers (1980) were applied for comparative purposes. Statistically, all four methods supplied results within the same order of magnitude, with Theis and Cooper-Jacob correlating extremely well. Results from the Logan and Birsoy-Summers methods correlated very well too, but the T-values calculated via Logan’s method were almost double those obtained from the step-drawdown data analysed via the Birsoy-Summers method. The combined results adhered to a developed model-setting-scenario approach where each borehole can be evaluated based on three parameters. Firstly, the model refers to the potential water-bearing and/or water-barring features. In the study area, it was found that water predominates in the Hout River Shear Zone, and that the neotectonic stress fields have little influence on determining the orientation of favourable water-bearing structures. Geological contacts often resulted in higher yielding boreholes than geological structures. Secondly, the setting refers to the climatic and tectonic setting of the site. This determines the recharge and the orientation of structures. Based on this, supposedly closed structures (due to prevailing neotectonic stress fields) often supplied higher yielding boreholes than the supposedly open structures. Rainfall and climate however had little influence on the results. Finally, the scenario ranks a borehole in terms of high, intermediate or low transmissivity and subsequently potential yield. High T-values typically exceeded 100 m2/d whereas low T-values were generally below 5 m2/d. Significantly low yielding boreholes therefore formed part of the Low T Scenario, and high yielding boreholes of the High T Scenario. Copyright / Dissertation (MSc)--University of Pretoria, 2008. / Geology / unrestricted
2

The Development of Appropriate Brine Electrolysers for Disinfection of Rural water supplies

Siguba, Maxhobandile January 2005 (has links)
>Magister Scientiae - MSc / A comparative study of electrolysers using different anodic materials for the electrolysis of brine (sodium chloride) for the production of sodium hypochlorite as a source of A comparative study of electrolysers using different anodic materials for the electrolysis of brine (sodium chloride) for the production of sodium hypochlorite as a source of available chlorine for disinfection of rural water supplies has been undertaken. The electrolyser design used was tubular in form, having two chambers i.e. anode inside and cathode outside, separated by a tubular inorganic ceramic membrane. The anode was made of titanium rod coated with a thin layer of platinum and a further coat of metal oxide. The cathode was made of stainless steel wire. available chlorine for disinfection of rural water supplies has been undertaken. The electrolyser design used was tubular in form, having two chambers i.e. anode inside and cathode outside, separated by a tubular inorganic ceramic membrane. The anode was made of titanium rod coated with a thin layer of platinum and a further coat of metal oxide. The cathode was made of stainless steel wire. An assessment of these electrolysers was undertaken by studying the effects of some variable parameters i.e. current, voltage and sodium chloride concentration. The flow rate was kept unchanged at 50ml/h anolyte and 140ml/h catholyte since it was found to be optimum flow rate for chlorine generation. Figures of merit of the electrolysers were calculated on the basis of three sets of measurements. Analytical methods used for the determination of sodium hypochlorite concentration were iodometric and N, N-Diethyl-p- Phenylenediamine (DPD) titration methods. The DPD titration method was used to determine the chlorine concentration of less than 1mg/L, while the iodometric titration method was used to determine chlorine concentration of ImgIL and above. Sodium chlorate present in the hypochlorite solution was also determined using a spectrophotometric method. The cobalt oxide electrolyser has been shown to be superior as compared to the ruthenium dioxide and manganese dioxide electrolysers in terms of hypochlorite generation. Sodium chlorate was present but at concentration levels not hazardous for use in dosing water for drinking purposes. Analysis of hydroxyl radicals was undertaken since there were claims that these are produced during brine electrolysis. Hydroxyl radical analysis was not successful, since sodium hypochlorite and hypochlorous acid interfere using the analytical method described in this study.
3

The role of the department of water affairs and forestry in the empowerment of the Kei district council in the Eastern Cape

Mabunda, Gezani Samuel January 2002 (has links)
Masters in Public Administration - MPA / According to the Constitution of Republic of South Africa (Act 108 of 1996) it is the responsibility of local government to provide basic and effective water services to all consumers in its area of jurisdiction. The Water Services Act (Act 108 of 1997) further supports this concept and establishes the institutional framework for service delivery and an enabling environment for development of the sector. In the spirit of co-operative governance the department of Water Affair and Forestry is obliged to provide this support to local government around the issues of water services provision but this support needs to be located within the legislative laid out in local government legislation. The nature of capacity support to Kei District Council is that it requires intensive initial support to ensure that it is able to fulfil its service functions, including those outlined in the Water Services Act. This requirement for intensive initial support is due of the following: (a) Kei District Council was previously not responsible for water services, (b) it require support to set up structures and systems for managing and monitoring water Services, (c) it need to develop water services expertise, (d)The Transitional Local Government process places an enormous challenge on Kei District Council to gear up for its role as developmental local government, and (e) the Water Services Act has introduced new requirement and clarified the water services authority functions that municipalities are required to fulfil.

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