Membrane fouling properties of hollow fiber membranes prepared from cellulose acetate derivatives

Three types of hollow fiber membrane were prepared from cellulose acetate (CA), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP) via the thermally induced phase separation (TIPS) method. The three membranes had almost the same water permeability, surface roughness and zeta potential. However, hydrophilicities clearly differed between the three membranes, decreasing in the order CA > CAB > CAP. Hydrophilicity, surface roughness, zeta potential, water permeability, solute rejection and other membrane properties affect membrane fouling and the latter is quite complex. In this work, the effect of changes in membrane hydrophilicity on fouling behavior was investigated, while other membrane properties were kept virtually constant. The most hydrophilic membrane, CA, showed the highest antifouling properties for humic acid and BSA. In addition, backwashing was most effective with the CA membrane. Thus, a hydrophilic membrane surface was useful for backwashing as well as reducing flux decline.