Elaboration of Ceramic Pot Filter from Kaolinite (Cameroon Clay) for the Elimination of Suspended Particles from Domestic Drinking Water

Abstract

The objective of this work was to elaborate ceramic water filters from Kaolinite (Cameroon) clay for the elimination of suspended particles from domestic drinking water. In Sub-Sahara Africa and in Cameroon in particular health issues have been linked to the consummation of domestic tap water of high turbidity values both in the rural and urban areas. In order to remedy these problems, ceramic water pot filters have been elaborated in a pilot scale unit with aim of putting in place a unit production. The chemical composition, the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analyses of the raw materials (clay and rice husks) was determined. The crystal phases and scanning electron microscope of Wack clay was also determined. The ceramic pot filter membranes were fabricated from the formulations 70/20/10 of clay/porogen/chamotte respectively with the particle size of the raw material less than or equal to 500 μm. The formulated ceramic pot filters were then sintered at 900 ˚ C in a furnace. These ceramic pot filters were characterized by determining their porosity, withdrawal percentages, water permeability, mechanical and chemical resistance. The study of the efficiency consisted in evaluating the retention rate and permeate flux with respect to time (days) with synthetic water suspensions of turbidity 100 NTU and particle size of 2 μm. The ceramic pot filters were made aiming at studying the efficiency after physical defouling of filters. Physical defouling consisted in brushing the inner surface of the ceramic pot filters with water and drying them at ambient temperature after being used for 11 days and reusing them under the same initial conditions. The produced ceramic pot filter had a volume of 4 L, an average porosity of 36.15%, shrinkage in mass or withdrawal percentage of 18.23%, a water permeability of 59.6 × 10 3 L ∙ h − 2 ∙ m − 2 , mechanical resistance of 6.8 MPa and corrosion resistance of 1.6% in acidic medium and 0.8% in alkaline medium. The evaluation of the retention efficiency reveals that the retention rate of 99.9% was obtained from the 9 th day of filtration reducing the turbidity value from 100 NTU to less than 0.1 NTU. From the filtration test carried out during the 11 consecutive days, the flow rate varied between 1.46 L ∙ h − 1 to 2.63 L ∙ h − 1 . Similar results of retention and flow rate were obtained after physical defouling of the ceramic pot filter membranes and re-using for 11 consecutive days, showing the efficiency of the ceramic pot filter membranes in eliminating suspended particles from drinking water. Cost evaluation for the production unit reveals a total cost of production for 50 ceramic pot filters of 1593.6 USD consisting of fixed assets and variable assets. An estimated selling price of 3.3 USD was obtained which is affordable for both the urban and rural population in Cameroon and in sub-Saharan Africa.