Cellulose acetate bio-based membrane: optimization of the fabrication conditions and organic dye separation efficiency

The increasing scarcity of freshwater sources and the global demand for water is expected to grow in the oncoming decades which urge the need to develop alternative water supplies, including reuse and recycling of wastewater. Membrane-based separation for water treatment is playing an increasingly important role to provide adequate water resources of the desirable quality. H2020-MSCA-IF-project "Enhanced-MUMs" targets the development of advanced multifunctional and low-cost polymeric membranes for water treatment and desalination. The current work represents optimization of the preparation conditions of cellulose acetate membranes by phase inversion technique using automatic film applicator and water as a coagulation medium. The prepared bare membranes have a well-defined anisotropic microscopic structure with a pure water flux range from 150 L/m2.h to 990 L/m2.h using different membrane thicknesses and under different applied pressures. Modified membranes have been prepared using salt coagulation bath as well as in-situ salt addition to the polymer solution during the membrane fabrication. It was found that the preparation conditions greatly affect the microscopic and surface characteristics.The prepared membranes under different conditions were investigated for the separation organic dyes from their aquose solutions either by absorption or by rejection. Cationic and anionic dye models were investigated to understand the mechanism of the separation process. Other aims of the project are to improve the microscopic structure with regard to the pore size and structure and improve the mechanical properties of the modified membranes. In addition, the project aims also to study and control the fouling characteristics of the membranes by imparting photo-induced properties for enhanced antimicrobial and antifouling effects.