Written by Sonny Lightfoot, Research Associate and Technician at Centre For Print Research (CFPR)
In the latest issue of Craft Magazine they look at the work of Potters for Peace (PFP) ‘a non-profit, social justice organization focused on using clay based solutions to address the problems of poverty.’ The amazing work PFP have implemented and published around locally made ceramic water filters has been a big inspiration for us here at UWE working on Heathy Waters. The literature produced by PFP has been a useful resource to start our own research especially around the use of burn-out material to be added to clay to increase precocity. Where PFP have developed a process where the ceramic filters are produced with a mould and a hydraulic press, we are looking at the already existing skills and process of local potter’s to hand building and pit fire water filter, like that of the craft potters in Kisoro Uganda, who currently produce ceramic cooking stoves.
Our initial ceramic tests have been focused on producing ceramic beads of different porosity to work as a medium for a biofilm to grow within a water filter. We have looked at two processes for these beads, extrusion, a well-established industrial process, and a organic foam impregnating method in which we laser cut compressed cellulose sponge that is then expanded in water then dipped in a ceramic slurry.
Our next tests will be looking at producing a hand build ceramic water filter using a basic hand building technique known as coiling, which is more in line with the hand building process of the Ugandan potters. The pots will be made from terracotta clay with sawdust added in different percentages they will then be tested to establish the balance between increasing precocity to reduce time taken for the water to pass through the filter but still maintain a high efficacy of removing bacteria and pathogens.