Permeability, Strength and Filtration Performance for Uncoated and Titania-Coated Clay Wastewater Filters

Problem statement: Wastewater problems continue to be a relevant issue, particularly in urban areas. One promising low-cost material for manufacturing porous ceramics as water filter is clay. Clays can be blended with other materials such as polymers to obtain functional ceramic materials. Approach: Ceramic wastewater filters were fabricated from clay using both sol-gel and simple mixing methods followed by hot-pressing and calcination. Polyethylene Glycol (PEG) was used as a pore-forming agent. Results: Varying the clay:PEG ratio modified the membrane permeability between 1.65×10^-16 m² and 3.16×10^-15 m² for the sol-gel membranes and between 1.38×10^-16 and 8.72×10^-13 m² for membranes prepared by simple mixing. The strength ranged from 0.28 MPa-1.71 MPa for the sol-gel membranes and from 0.05-0.90 MPa for samples prepared by simple mixing. The filtration performance was tested using aqueous solutions of Methylene Blue (MB). The concentrations of MB remaining in the solution varied from 0.98-1.44% for sol-gel filters and from 1.50-38.05% for filters prepared by simple mixing. Conclusion: We succeeded in making ceramic as filter from clay. The porous ceramic can be used to reducing concentration of pollutant simulated. The model introduced has succeeded to explain the experimental observations with percolation approximation.