Preparing Sustainable Membranes Made From Zeolite–Smectite for Treating Textile Wastewater and Pulp Industry Wastewater

Abstract

Low‐cost separation techniques are crucial for treating wastewater. Developing inexpensive membranes made from natural materials has become a popular research area in recent years. Tubular membranes were produced by adding 10% organic additives to a mixture of 80% zeolite and 10% smectite. New composite ceramic membranes from zeolite and smectite were prepared using the extrusion method to create a plastic paste and characterized using XRD, SEM, EPMA, and FTIR. The impact of sintering temperature (Tsint, 850–950 °C) on membrane properties, such as microstructure, mechanical strength (MS), water permeability, and filtration performance, was investigated. The MS and shrinkage rate increased with Tsint. At 950 °C, the resulting composite membrane exhibited a high MS of over 65 MPa, a relatively low porosity of 30%, appropriate for membrane filtration, and a water permeability of 65 L·h⁻¹·m⁻2·bar⁻¹. When applied to remove pollutants from wastewater, this membrane demonstrated a high color retention of 98.4% from an aqueous Evans blue‐colored solution (Effluent 1). For extensive application to wastewater treatment, this membrane showed a high‐efficiency level for treating real effluent produced by the pulp industry, removing 62.4% of chemical oxygen demand, 36% of hardness, and 82% of color. Finally, an ultrasonic cleaning procedure allowed the restoration of 70% of the initial permeability after four cycles for both effluents. Thanks to the exciting properties offered by these membranes and their competitive cost of less than $ 20·m−2, these membranes are appropriate for treating industrial wastewater.