Manufacturing of tubular ceramic microfiltration membrane based on natural pozzolan for pretreatment of seawater desalination

This work describes manufacturing of low-cost tubular ceramic microfiltration membrane made from natural pozzolan. Firstly, the tubular ceramic support was prepared by extrusion technique followed by sintering at low temperature of 950 °C. The extruded paste is essentially composed of pozzolan powder (<200μm), clay (<68μm), some organic additives and water. This formulation is conducted to obtain a ceramic support with uniform porous structure and high water permeability. Secondly, the membrane layer was prepared by cross-flow filtration of suspension containing the pozzolan powder (<45μm), polyvinyl alcohol and water, thereafter the membrane was dried and sintered at 950°C. Scanning electron microscope analysis showed that the membrane has homogenous structure and is free from any defect. In addition, the average pore size and water permeability parameters were respectively 0.36μm and 1444.7L/h·m2.bar.