Preparation and Characterization of a SiO2/ Mullite-Alumina-Zeolite (MAZ) NF Membrane by Cross-Flow Filtration Process

This work describes manufacturing of low-cost tubular ceramic nanofiltration membrane made from cheap and convenient accessible raw materials. Firstly, the tubular ceramic support was prepared by extrusion technique followed by sintering at 1250 °C. The extruded paste is essentially composed of kaolin clay ( 50 µm), α-alumina powder ( 50 µm), natural zeolite ( 50 µm), some organic additives and distilled water. This formulation is conducted to obtain a ceramic support with uniform porous structure and high water permeability. Secondly, the intermediate layer was prepared by cross-flow filtration of suspension containing the natural zeolite powder (≈ 450 nm), arabic gum and distilled water, thereafter the membrane was dried and sintered at 1150 °C. At finally, SiO2 nanoparticle/arabic gum solution as selective layer, embed on the inner surface of the membrane by cross-flow filtration techniques. The experiments of permeate flux for the SiO2 NF membrane were conducted. The results show that the NF membrane has been prepared successfully. Investigate of porosity and shrinkage showed that the support membrane (50:30:20) sintered at 550, 750, 950, 1150 and 1250 ℃ had porosities of 55 , 54 , 49, 45 and 38 % and radial linear shrinkages of 3, 3.1, 3.27, 4.5 and 10.23%, respectively