Mitigation of particle deposition onto membrane surface in cross-flow microfiltration under high flow rate

We investigated the effects of flow rate, particle diameter and initial flux on fouling mitigation in cross-flow microfiltration of suspensions containing silica and PMMA particles. Regardless of the difference in PMMA and silica, the fouling mitigation was more effective at a larger flow rate and larger particle diameter, due to sufficient hydrodynamic lift force. Lower initial flux was also shown to be better for the mitigation of fouling. Fouling was completely prevented when cross-flow filtration of particles with 1.5 μm of diameter was carried out under a flow rate of 30 L min−1 and 4.0 × 10−5 m3 m−2 s−1 of initial flux. We also demonstrated that classification of bi-dispersed particles using membranes could be achieved by the cross-flow microfiltration, where fouling by larger particles than the pore size was completely prevented because of the sufficient hydrodynamic lift force and only the smaller particles permeated through the membrane. This classification remained stable for 3 h while maintaining the flux and permeation of the smaller particles.