Simulation study on mitigating permeate flux decline with electroosmotic flux in dead-end ultrafiltration process

Piezoelectric membranes establish electrokinetic phenomena, including electroosmotic flow, to mitigate membrane fouling in the ultrafiltration process. This study employs numerical simulations to evaluate the role and impact of the electroosmotic flux effect on permeate flux decline and fouling mechanisms in the dead-end filtration process for silicon dioxide particles. This research demonstrates that electroosmotic flux significantly alleviates flux decline across varying values of surface zeta potential, membrane porosity, particle size and inlet concentration. Specifically, the electroosmotic flux effect is most pronounced in reducing flux decline when the surface zeta potential is higher and the membrane structure is more porous. This reduction in flux decline is attributed to the enhanced lift and drag forces generated by electroosmotic flux near the electrical double layer, which prevents rapid initial adhesion and subsequent fouling, such as internal blocking and cake layer formation. Additionally, the electroosmotic flux effect is most effective with smaller particle sizes and higher feed concentrations, helping to mitigate flux decline that would otherwise occur in the absence of electroosmotic flux. Compared to experimental and modelling investigations, the electroosmotic flux effect is shown to complement a reduction in permeate flux drop to facilitate the longevity of membranes in the ultrafiltration process. © 2024 Elsevier B.V.