Nanoporous Ceramics for Water Filtra tion

Abstract

Over four billion cases of diarrhea that occur worldwide each year result ill about 18 million deaths. In the developing countries (in Africa) over 35% of the population suffers from diseases related to unsafe water supply and sanitation. Over 38% of Kenyans lack access to safe drinking water Point of Use Water Treatment Systems (PUWTS), such as ceramic disc water filters: is one of the proven PU\VTS methods and has been shown to reduce diarrheal prevalence by an average of 80%. Although ceramic water filters have been proven effective for improving water qualiry. users and implementers often express concern over their inability to produce a sufficient quantity of water due to their slow now rate. If now rate could be increased by altering the filter design: it would improve the ceramic filter's viability as a scalable House Hold Water Treatment System option. The objective of this study was to create a strong filter design that exploits physics of nanoscale for water purification with a faster now rate than the traditional design, wh ile maintaining high levels of bacterial reduction. In trying to achieve this goal, new filter designs were created by increasing the ratio of combustible material (sawdust) to clay and then firing at different temperatures ranging from 800-100ave These new filters were tested for bacterial reduction and flow rate. The majoriry ofalternative designs did have increased now rates: however they were not able to consistently reduce high levels of E-coli from influent water. '·Minor alterations in filter design or raw materials plus the firing temperature can affect the performance of locally produced ceramic disc water filters 10 the point where their ability to produce safe drinking water is compromised. The results of this research suggest that the mean flow rate for a properly functioning filter is 4.44 L'day for code III (50% sawdust) fired at 950°C. This flow rate is more than ~9 Iitres per day as recommended by \VHO on average conditions. To increase the efficiency, the disc ceramic water filters were dipped in 300ml of 2001l1g!L of colloidal silver nanopartic le for 45 seconds .