Preparation and characterization of tubular cermet membrane for microfiltration separation: application to the treatment of textile wastewater

Abstract

Low-cost ceramic–metal composite (cermet) membrane supports have been elaborated and characterized. A plastic paste was prepared from kaolin (K), feldspar (F), sand (S), and two types of aluminum (i.e., waste aluminum alloy (WA) and commercial aluminum (CA)) mixed with water. This was followed by the preparation of a ceramic porous tube by extrusion and sintering at a temperature of 1350 °C for 2 h. The samples were then characterized using porosity, permeability, scanning electron microscopy (SEM), and chemical and mechanical properties to evaluate the effects of the addition of aluminum to the porcelain matrix on the mixture (50% K, 25% F, and 25% S). The microfiltration active layer was added on the support by a slip casting method using 63 µm kaolin powder, water, and polyvinyl alcohol solution (PVA); after drying at room temperature for 24 h, the microfiltration layer was heated to 650 °C for consolidation. SEM observation showed homogeneous layers without cracks with 5 µm and 9 µm thick layers for the two membranes prepared. Application of the membrane for the treatment of textile wastewater showed a turbidity removal of more than 98% and a chemical oxygen demand of more than 85%. This was a much better separation performance when compared to other membranes.