Hydrology
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Browsing Hydrology by Author "Basson, A.K."
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- ItemDeveloping a low-cost ceramic micro-porous water filter for removal of microorganisms that cause common diseases(University of Zululand, 2012) Simonis, Jean Jacques; Kelbe, B.E.; Revaprasadu, N.; Basson, A.K.Africa is one of the most water-scarce continents on earth and the lack of potable water is responsible for the death of approximately 4 900 children every day. Water can be effectively decontaminated by using a household ceramic water filter. The local production of low-cost water filters suitable for the removal of suspended material and pathogenic bacteria from water sources, especially in rural areas, provides a promising solution to the problem and is therefore important to pursue. The traditional slip casting process was used develop a micro-porous ceramic water filter. The method was found to be more suitable than either extrusion or die casting for manufacturing a locally suitable, low cost ceramic water filter. Slip casting, requiring limited expensive equipment, usage of locally available raw materials, labour and expertise makes this the only promising method for manufacturing ceramic filters in a rural, non-technical setting. Using milled lithium alumino-silicate had the main advantages of thermal shock resistance and dimensional stability because of the material’s zero thermal expansion at firing temperatures. Milling tests based on the Andreasen packing model were used for obtaining the best particle packing for the raw material recipe. The material also provides dilatant rheology matching the rheology of the organic carbon poreformer. The candle- type filter required less raw material compared to the other low cost filter such as the pot- type filter from (PfP). The particle size of the pore-former provided us with small pores around 3 microns after firing for the elimination of bacteria from drinking water. These pores were much smaller and more effective when compared with Potters for Peace (PfP’s) pore size of 16-25 micron. The zero thermal expansion (adopted ZTE product name) helped to prevent damage (cracking) to the product during heating and gave accurate control of the ultimate filter size after sintering. The large apparent porosity results of between 67-73 per cent for the finished product provide a specific surface area of 7 m2 g-1 and a high flow rate which explains the filtration efficiency of the filter. The 32 minute retention time of water further helps with the filtration effectiveness. Bacteriological testing exceeded all expectations. The product was tested using water contaminated with high concentrations of selected bacterial cultures as well as with water from local polluted streams. -i v - The product complies with the WHO (2011) recommendation requirement for household water treatment (HWT) technologies of a LRV ≥ 4 (log reduction value). With correct cleaning and basic maintenance, this filter can effectively provide clean drinking water for rural families affected by polluted surface water sources. This product can immediately be useful to families placed in situations where polluted drinking water causes distress. The filter could provide a low-cost solution for the millions of people without access to potable water in Africa. Furthermore, such a project provides opportunities for local financing and innovation. The method of slip casting for the manufacture of porous ceramic used in this study has been showed to work very successfully. The filter requires fewer raw materials, energy for the shaping- and firing- process, finishing, storage space, it is small, compact, and more effective against bacterial load and has a flow rate 3-4 times faster than any other low cost manufactured filter. The low unit manufacturing cost, places Outbac in a strong position, to also compete on a price-only-basis with other low cost, ceramic filter producers in the world.
- ItemThe evaluation of existing household water treatment system using World Health Organisation recommendations.(University of Zululand, 2014) Selepe, T.N.; Simonis, J.J.; Basson, A.K.Household water treatment technology coupled with nanotechnology research have been developed and managed to treat water at household level. This technology will help address United Nation Millennium Goals (UNMG) 2015 of access to safe drinking water within South African Development Countries (SADC). University of Zululand (UNIZULU) Hydrology Department has developed a low cost household treatment system (HWTS) using a traditional slip-cast process of inorganic and organic compounds mixed together and fired at high temperature to produce pores. The filter has shown high strength, high chemical resistance, and thermal stability and proved very durable when subjected to harsh operational conditions. When the filter properties were compared to other low cost HWTS, it shows increased porosity of 69%, pore sizes of 0.3- 4µm and flow rate of 1-2L/h. The HWTS was initially impregnated with metal oxides such as silver oxide (AgO), copper oxide (CuO), zinc oxide (ZnO) and iron oxide (FeO) using capillary suction dried in kiln to improve viral removal. The impacts of these metal oxides were tested on selected bacteria, protozoa and bacteriophages. The selected bacteria show log reduction value (LRV) of 5, protozoa LRV of >6 and bacteriophages LRV 2.8 for AgO and CuO showing LRV of 4. Field testing was repeatedly performed over a period of one month. Cleaning of HWTS was only done at the end of testing. The results were as follows: somatic phages were reduced by 99.999% while Fspecific phages showed a reduction of 99.999%. This concludes that UNIZULU locally developed HWTS has met WHO performance standards and can be utilised to uplift the impact of safe drinking facing the SADC.
- ItemProduction of bioflocculant from marine bacteria and its application in the treatment of coal wash plant fines(University of Zululand, 2015) Dafel, Jade; Simonis, J.J.; Basson, A.K.A total of 33 water and sediment samples were randomly selected from the marine environment on the North Coast of KwaZulu-Natal (KZN), South Africa. Strains were isolated and screened for their potential to secrete bioflocculants and tested for flocculating activity with a kaolin suspension. The strains that produced bioflocculants with a high yield of flocculating activity (above 60%) were selected for optimisation and further flocculating tests using coal mine slurry. One strain with good flocculating abilities for both a kaolin suspension and coal mine slurry (74% and 76% respectively) was analysed using its 16S rDNA nucleotide sequence and was identified as Bacillus cereus. The bioflocculant bacterium was optimal when glucose (40g/l) and urea, as the carbon and nitrogen sources, a pH of 4 and Ca2+ as the cation were utilized. The exceptional flocculating performance of Bacillus cereus demonstrated good potential for replacing the chemical flocculants that are currently used in flocculating coal mine slurry generated at Tendele Coal Mine (TCM) located in KZN.