PREPARATION AND CHARACTERIZATION OF CERAMIC WATER FILTER: FOR WATER TREATMENT

Abstract

Water is basic in life. Clean water is the key to a healthy society. A billion cases of diarrhea occur worldwide each year that result in million deaths. Ethiopia is facing the challenge of safe water coverage in rural and urban. The communities in the Ethiopia rift valley are also highly affected by fluorosis because of the high concentration of fluoride in drinking water. Inorganic ceramic is receiving more attention in recent time due to their unique characteristics which include different pore structures and content, hydrophilic surfaces, high chemical, thermal and mechanical stabilities which offer avenues for application in water treatment. The aim of this work was to develop a ceramic water filter with a good flow rate, which is capable to remove chemicals as well as microbial contaminants, by investigating the effect of altering specific design variables. Ceramic water filters were developed from different ratios of local raw materials: clay, sawdust, grog, with and without bone chars and sintered in (800-1000oC) temperature at different intervals for 6hrs. The developed ceramic filters were characterized with FE-SEM, EDX, XRD, pH meter, BET and FT-IR. The flow rate, porosity, conductivity, pH of filtered water and the removal efficiencies (microbial, water hardness agent’s, fluoride, nitrite, iron, and turbidity) were analyzed. The ceramic filters with 25-35% sawdust, 50-60% clay and 15% grog that sintered in the temperature range of 900-950oC showed better flow rate (1.5-2.5 L/h), E.coli removal efficiency is greater than 99%. The pH, conductivity and other water quality parameters of the filtrate are in WHO standard. The average total porosity, BET surface area and average pore diameter determined for C900-50-15-35 ceramic filter were 36%, 6.183 m²/g, and 4.83 nm respectively. The porosity of the filter; C900-50-15-35 (36.33±0.05), its flow rate (1.91±0.55). The removal efficiency of nitrite (70.00±0.22 %) and fluoride (96.8±0.41%) are in the WHO standard. The Phase and functional group identification of sintered filter investigated with x-ray diffraction and infrared spectroscopy revealed the presence of mixed phase and hydroxyl functional group on the surface of the sintered filter. Field emission scanning electron microscopy (FESEM) revealed the porous nature of sintered filter elements with an average pore size of 5 nm. The EDS analysis results of the filter used for hardness and iron removals showed more concentration of Ca2+, Mg2+, Iron and less ion concentration of Na+ and K+ due to the ion exchange reactions. Statistical ANOVA tests showed a significant difference between ceramic filters with various compositions in their removal efficiencies of E. Coli, nitrite, and porosity ( p < 0.05).