Microfiltration Studies Using Low Cost Ceramic Membranes

Abstract

In the past two decades, significant advances in membrane technology research have been reported. Amongst various membrane applications proposed so far, microfiltration (MF) and ultrafiltration (UF) are the most significant in chemical and biochemical processes. Polymeric and ceramic membrane materials are the most relevant materials used for MF and UF membrane processes. While polymeric membranes are inexpensive and are prone to a greater degree of fouling, ceramic membranes are expensive and possess higher corrosion and mechanical resistance. Therefore, the preparation and characterization of low cost ceramic membranes is always encouraging to further the industrial cost effectiveness of membrane technology. This work presents the preparation, characterization and applications of low cost ceramic membranes suitable for MF and UF applications. Among various industrial applications of membranes, treatment of oily wastewater and MF of mosambi, orange and pine apple juice were chosen as the most important areas of research where low cost ceramic membranes can be used as an alternative to conventional fouling prone polymeric membranes. The entire work carried out in this research work is divided into five major parts: A) Dead end microfiltration of oil-water emulsions using low cost ceramic membranes prepared with uniaxial dry compaction method. This work addresses the comparative assessment of uniaxial dry compaction and paste methods for the preparation of low cost ceramic membranes. Kaolin based low cost membranes were fabricated using uniaxial dry compaction method. Fabricated membranes were characterized and used for the treatment of synthetic oily waste water solutions. It was observed that in comparison with the paste method, the membranes prepared with uniaxial dry compaction method possessed wider pore size distributions. Amongst several membranes, the membrane PM1 fabricated at a pressure of 25 Mpa provided highest flux of 24 स 10 6 m3/m2.s and an oil rejection of 95.2 % but with a fouling index of 29.47 % at a pressure of 206.70 kPa. On the other hand, PM3 membrane provided a lower fouling index of 15.54 % at a pressure of 206.70 kPa with a membrane flux of 8 स 10 6 m3/m2.s and a rejection of 97.9 %. For the obtained membrane morphology and chosen feed concentration, combination of pore blocking models provided best fit to represent flux decline data.