Nonporous ceramics filters for water purification
Abstract
ABSTRACT
Clean water is a necessity for healthy human beings so is its provision and access. This study was undertaken to evaluate the performance of ceramic water filters in reducing the E. coli in contaminated water. The effect of firing temperature and volume porosity (P) of a disc-type ceramic water filter on the filtration and E. coli removal efficiency is presented. The porosity of the ceramic water filters was varied by changing the percentage of sawdust added in the red clay and measured by the absorption test method using Archimedes’ principle and the E. coli were tested using the membrane filtration procedure. Modulus of rupture (representing the mechanical strength) of the filters was also determined by use of an Instron 1185 compression/tension testing machine.
The porosity of the filters was found to be directly proportional to the percentage of the sawdust. The filtration rate of water increased with the increase in the porosity of the disc ceramic water filters. The strength of the filters, on the other hand, was inversely proportional to the amount of sawdust added to the clay. Ceramic water filters designs (clay to sawdust ratio 60:40, 55:45, 50:50 and 45:55) fired at 950 °C for five hours had total E. coli removal efficiency of 99.99, 99.98, 99.97 and 86.76 percent respectively.
Alterations in filter’s design or raw materials plus the firing temperature affected the performance of the produced ceramic disc water filters. The results of this study suggest that the mean flow rate for a properly functioning filter (50% sawdust) fired at 950 oC is 1.7 L/h. This flow rate is more than 2.9 litres per day as recommended by World Health Organization on average conditions. This filter also removed more than 99.97% of E. coli
Publisher
University of Nairobi