Simple and effective corrugation of PVDF membranes for enhanced MBR performance

Membrane fouling control in membrane bioreactors (MBRs) can be achieved by improving membrane properties. In this study, corrugated flat sheet polyvinylidenefluoride (PVDF) membranes were fabricated, characterized and tested in a lab-scale MBR for improved filterability and fouling resistance. A simple imprinting step was successfully developed and applied as part of the membrane preparation procedure, via phase inversion, to form corrugations on the membrane surface. The corrugation consisted of valleys-and-hills topography, which increased membrane effective surface area (A sub(E)) by ~50%. It also increased the membrane mean pore size (PS) as a result of changes in formation mechanism. Both higher A sub(E) and larger PS increased membrane permeability to about 5-6 times compared to the non-corrugated membrane, prepared under similar conditions. Surface corrugations reduced membrane fouling propensity as observed from the flux-stepping test and a lab-scale MBR operation, without affecting permeate quality.