Understanding the influence of hydraulic conditions on colloidal fouling development by using the micro-patterned nanofiltration membrane: Experiments and numerical simulation

Surface patterning has emerged as a promising method to control membrane fouling by disturbing the flow field on the membrane surface. In this study, fouling development was non-destructively characterized by optical coherence tomography (OCT), while the micro hydraulic conditions and particle migration trajectories were investigated by using Computational Fluid Dynamics (CFD). Preliminary results demonstrated remarkable anti-fouling performance of the MNF membrane, and CFD simulation revealed that the local flow velocity on the apex area of patterns was greatly accelerated and the vortex among the valley regions was continuously generated. These hydraulic characteristics resulted in the enhancement of the hydrodynamic lift force (f_L) and decrease of the permeation drag (f_D) enforced on the retained foulants by the MNF membrane. Moreover, particle trajectories simulation integrated with comprehensive forces allowed to understand the influence mechanism of the flow field around MNF membrane surface on particle deposition. This study presents a new understanding of the anti-fouling mechanism of the MNF membranes and provides new insights into the design of self-cleaning membranes.