Clay Ceramic Materials For Water Filtration: Properties, Processing And Performance

ABSTRACT

Ceramic water filters are promising household water treatment technology, as they are capable of removing waterborne pathogens and thereby reducing diarrheal disease. Flow rates are the main quality control criterion for manufacturing, and multiple theoretical flow rate models have been published. This dissertation presents the results of combined experimental and theoretical studies of flow rate variation in ceramic water filters in frustumand disk-shaped ceramic water filters. Also investigated is how clay mixtures/plasticity affects the strength of the ceramic water filters. Furthermore, residual strengths of filter specimens that had undergone cold-shocking at temperatures 750, 850 and 950 are presented and trends explained via bridging models. Firstly, in this dissertation six frustum-shaped ceramic water filters of the same clay:sawdust composition were tested. Each ceramic water filter was filled with water and allowed to filter 20 times. Each time, the flow rate and water level are measured for consecutive 12 hours. Permeability values are estimated for each run of the ceramic water filters. Statistical analysis was performed on flow rates (in the first hour), mean flow rates and estimated permeability values. The flow rate values (in the first hour) for the six ceramic water filters were found to be between 1.4 – 3.0 L/hr. An effective permeability was obtained for ceramic water filters with a range of micro- and nano-scale pore sizes. The statistical variations in the flow rates and effective permeabilities were elucidated along with the potency of a multiple ceramic water filter system for scale-up studies in serving communities that need portable water.