Assessment of cellulose acetate membranes separation efficiency in wastewater treatment

Water as a high value resource is constantly used in every activity (from households to industries) and that’s why wastewater treatment is essential to ensure the protection of human and environmental health by removing pollutants and pathogens from wastewater before releasing into environment or reused. Among the emerging technologies, membrane separation processes are efficient, eco-friendly and relatively low-cost solutions that address this problem. This work explores the benefits of cellulose acetate membranes in wastewater treatment. These natural based membranes offer a sustainable and eco-friendly approach in removing pollutants due to their biodegradability, high permeability and selectivity, showing high efficiency in the separation process. Also the fouling degree is quite low which ensures multiple separation cycles without anti-fouling treatment which overall translates as cost-effective. Three types of cellulose acetate membranes (8%, 10%, 12% wt) were prepared by phase inversion. Each membrane was subject to morphological analysis using SEM which revealed an active layer between 4.468 – 8.324 µm. Secondly the membrane flow characteristics were measured at various pressures, obtaining a maximum average ultrapure water flow of 7868 L/m2h at 3 bar pressure for 8% CA membrane. Preliminary tests for real wastewater membrane separation showed a maximum efficiency of 93% for CA 8% and 12%, and 81% for CA 10%. The fouling degree was measured after 5 separation cycles showing 15.27% clogging for 12%, 45.12% for 8% and 45.30% for 10% CA. Total suspended solids were reduced from an initial concentration of 110-134 mg/L to values lower than 5 mg/L.