Optimizing the antifouling performance of mixed patterned membranes: a computational study for water treatment

Membrane fouling remains a major challenge in water and wastewater treatment. Membrane surface patterning offers a chemical-free approach to effectively control this issue. Previous research has focused on various surface pattern designs to mitigate membrane fouling, but has largely overlooked the combined effects of pattern dimensions and Reynolds number. In this study, we numerically investigate the filtration performance of four different membrane patterns—flat, triangular, mixed triangular-rectangular, and rectangular—by systematically varying pattern dimensions (100–800 μm), Reynolds number (200–1600), and salt (NaCl) concentration (14–70 mol/m3). This comprehensive approach allows us to assess the critical roles, these parameters play in enhancing the reverse osmosis filtration efficiency. For this purpose, the present study utilizes Computational Fluid Dynamics to simulate fluid flow and transport of diluted species in the vicinity of patterned membranes. In this study, the key parameters were evaluated, including the velocity streamline profile, wall shear stress, concentration polarization, permeate flux, and boundary layer thickness. Results reveal that the pattern dimensions and flow strength significantly affect the membrane’s antifouling performance and permeate flux, with parametric optimization being key to unlocking superior membrane performance. Remarkably, higher inlet flow velocities also help to reduce the boundary layer thickness across all patterned surfaces to even below that for flat surfaces, helping overcome an existing challenge in the literature. Overall, this work paves the way for further innovation in patterned membrane technology and supports its real-world application in enhancing water/wastewater treatment and reuse processes.