Preparation and characterization of macroporous SiC ceramic membrane for treatment of waste water

Abstract

Porous SiC based materials present high mechanical, chemical and thermal robustness and thus have been largely applied to water-filtration technologies. In this study, circular disc shaped SiC microfiltration membranes were prepared by dry pressing of commercially available SiC powder with yttria and alumina as additives followed by a low-cost oxide bonding technique. The membranes fabricated were characterized using standard characterization techniques like Scanning Electron Microscopy (SEM), Powder X-ray Diffraction (PXRD), porosity and pore size distribution analysis and compared with the membrane prepared by liquid phase sintering route from the same powder composition. Finally, water permeation studies were carried out in a standard membrane module and clean water flux was determined. These membranes were found well suited for treatment of oily waste water and grey water. The membrane prepared by oxide bonding method effectively removed ~ 89–93% of COD, ~ 77–86% of oil/grease and 88.4–92% of TSS from kitchen waste water and the removal efficiency are better compared to the membrane prepared by liquid phase sintering method. The effects of corrosions on the membranes were investigated in strong acid and alkali solution at 90 °C. The membranes prepared by oxide bonding method showed better corrosion resistance with retention of mechanical strength.