Fabrication of ceramic membranes with controllable surface roughness and their applications in oil/water separation

Knowledge of the surface roughness of ceramic membrane is useful for the understanding and improvement of their filtration performance. In this study, ceramic membranes with controllable roughness were fabricated with a template formed by PMMA particles uniformly deposited on the filter paper. Scanning electron microscopy (SEM) and vertical scanning interferometry (VSI) characterizations demonstrated that size distribution of template particles had an important effect on the morphology of membrane surface. The surface morphology formed by templating method was more homogeneous than that by the polishing method. The influence of surface roughness on the vegetable oily wastewater treatment was investigated. It was found that surface roughness had little effect on the pure water flux of membrane and oil rejection, but it played an important role in the filtration flux of oily wastewater. A high and stable flux was observed through the smooth membrane; its steady flux was obtained more quickly than that of the rough membrane. The results indicated that the smooth membrane is the control of membrane fouling during filtration of oily emulsion wastewater.