Evolution of Particle Deposits at Communicating Membrane Pores during Crossflow Filtration

Understanding the influence of operating conditions on fouling is a great challenge in crossflow membrane filtration since it is determined by a complex interplay between the shear force of the crossflow and the drag toward the membrane arising from the applied trans-membrane pressure. This study uses a coupled CFD-DEM approach to simulate the motion and deposition behavior of monodisperse spherical particles within a membrane-mimicking geometry. Trans-membrane pressure and crossflow velocity are varied to reveal their respective influence on different aspects of fouling at a pore scale. A visual analysis of the simulation results demonstrates distinct behavior regarding the initial deposition of particles and the resulting filter cake morphology, which can be attributed to defined phenomena. Additionally, quantitative data reveals that the dynamic fouling behavior is dominated by the applied crossflow velocity, while the resistance to the removal of particles by crossflow and the level of flux decline is mainly influenced by the trans-membrane pressure. This study links visual pore-scale phenomena to macroscopic filtration quantities, not only underlining the importance of pore-scale investigations but also narrowing the gap between pore-scale events and the filtration process