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Developing a low-cost ceramic micro-porous water filter for removal of microorganisms that cause common diseases

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dc.contributor.advisor Kelbe, B.E.
dc.contributor.advisor Revaprasadu, N.
dc.contributor.advisor Basson, A.K.
dc.contributor.author Simonis, Jean Jacques
dc.date.accessioned 2013-08-12T07:23:01Z
dc.date.available 2013-08-12T07:23:01Z
dc.date.issued 2012
dc.identifier.uri http://hdl.handle.net/10530/1208
dc.description Submitted to the Faculty of Science in fulfilment of the requirements of the degree of Doctor of Philosophy in the Department of Hydrology at the University of Zululand, South Africa, 2012. en_US
dc.description.abstract 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. en_US
dc.language.iso en en_US
dc.publisher University of Zululand en_US
dc.subject Ceramic filter en_US
dc.subject Micro-porous en_US
dc.subject Slip casting en_US
dc.subject Water filtration en_US
dc.title Developing a low-cost ceramic micro-porous water filter for removal of microorganisms that cause common diseases en_US
dc.type Thesis en_US

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