Ceramic monolith as microfiltration membrane: Preparation, characterization and performance evaluation

Abstract The aim of this study is preparation, characterization and performance evaluation of ceramic monolith as microfiltration (MF) for treating a solid-liquid wastewater. Kaolin as a cheap starting material was used for membrane preparation as an inorganic material. Polyvinyl alcohol (PVA) as binder was also used for membrane preparation and silica (SiO2) powder was used for preparation of synthetic wastewater. The membranes were formed via extrusion method. Response surface methodology (RSM) based on central composite design (CCD) was employed to design the membrane synthesis procedure. The independent variables were PVA concentration, sintering temperature and sintering time. Permation flux, Nephelometric Turbidity Unit (NTU) rejection, mechanical strength, porosity and pore size were considered as the responses. The optimized values of the independent variables were 0.5 wt%, 1150 °C and 5 h of PVA concentration, sintering temperature and sintering time, respectively. Based on the RSM results, the optimized membrane exhibited 80.9 kg m−2 h−1, 89.8%, 5.8 MPa, 49.3% and 1.2 μm for permeation flux and NTU rejection, mechanical strength, porosity and pore size, respectively. The membranes characterization was carried out using PSD, XRD, DTA/TGA and SEM analysis. The prepared membrane presented high practical separation potential and could be used for treating solid-liquid wastewaters.