Elaboration and characterization of novel two-layer tubular ceramic membranes by coating natural zeolite and activated carbon on mullite-alumina-zeolite support: application for oily wastewater treatment

The main objective of this research is the development of innovative two-layer tubular ceramic membranes with improved separation properties, high mechanical and thermal stability using affordable and easily accessible raw materials. In this regard, firstly, the clay-based ceramic support membrane was fabricated by extrusion technique using kaolin, alumina and natural zeolite. Besides, changes in thermal properties, shrinkage, porosity and mechanical strength of the prepared sample were evaluated as a function of treating temperature to obtain the best membrane support. Subsequently, the cross-flow filtration technique was employed to coat the natural zeolite and activated carbon over the support membrane to prepare the two-layer microfiltration membranes of MF-Z and MF-C, respectively. Finally, the performance of ceramic support, MF-Z and MF-C membranes were assessed during oily wastewater treatment. The results revealed that MF-Z and MF-C membranes could remove oil from 1,000 to 90 mg/L and 1,000 to 13 mg/L, respectively, while the concentration of oil in the permeate flux of the ceramic support was around 190 mg/L.