Cellulose acetate-based membrane for wastewater treatment—A state-of-the-art review

Abstract

During the past decades, many conventional technologies of wastewater treatment have been utilized, but they are ineffective in removing recently emerging substances of concern, such as pharmaceuticals, pesticides, personal care products, surfactants, plasticizers, and flame retardants. Membrane technologies have emerged as a great possibility in wastewater treatment since the 18th century, exhibiting high selectivity with high-quality effluent, low sludge production, size reduction of equipment, low energy, low cost, and can replace several treatment processes into a single one. Recently, cellulose acetate-based membranes are widely used for reverse osmosis (RO), ultrafiltration (UF), and nanofiltration (NF) purposes owing to their good toughness, cost-effectiveness, high hydrophilicity, high reflux, high biocompatibility, high salt removal, chlorine resistance, better antifouling properties, and efficient reduction of microorganism content. Moreover, the cellulose acetate membrane can easily be blended with other polymer or incorporated with nanoparticles and easily be functionalized to achieve specific physicochemical properties. Furthermore, as cellulose acetate is a green, energy-saving natural biodegradable polymer, it offers the potential to replace the traditional petrochemical membrane. This review focuses on the synthesis processes and properties of cellulose acetate-based membranes. The removal efficiency of recently modified cellulose acetate-based membranes to separate pollutants from wastewater and approaches to improve these membrane properties are discussed in this review. Future prospects and research directions are also suggested on the basis of the challenges faced during the materialization of these membranes.