New ceramic membranes for tangential waste-water filtration

Supports for microfiltration and ultrafiltration were prepared with Tunisian silty marls. Plastic pastes were prepared from a ceramic powder of silty marls mixed with organic additives and water. The pastes could be extruded to elaborate a porous tubular configuration. The supports fired at 1190°C and characterised by mercury porosimetry showed pore diameters centred near 9.2 µm and porosity about 50%. Microfiltration membranes were also prepared from Tunisian silty marls. The preparation of this ceramic layer was performed by the slip casting method. A deflocculated slip was obtained by mixing a mineral powder, PVA (12 wt %), and water. The water permeability measured for the membranes calcinated at 1000°C and with a mean pore size of 0.4 µm is 867 l.h−1.m−2.bar−1. These membranes can be used in tangential microfiltration.

In this work a new microfiltration membrane was prepared from natural powders derived from natural Tunisian materials. The ceramic support was formed by extrusion of a ceramic paste from silty marls (M11). The microfiltration layer, deposited onto the supports, was obtained by the slip-casting method using suspensions of silty marls. We note an excellent linkage between the support and the microfiltration layer. This membrane can be used for filtration of waste-water and production of drinking water. Tests are in progress in our laboratory.