Factors Affecting Reversible Pollution of Immersed Ultrafiltration Membrane in Treatment of Surface Water: Pilot Scale Studies

The main factors (i.e., permeate flux, mixture characteristics, and membrane materials) affecting the pollution of immersed ultrafiltration membrane (immersed-UF) during the treatment of surface water were investigated through pilot scale studies. The variation of the running pressure was used as an indicator of membrane fouling. It is indicated that the rate of running pressure increased rapidly when the actual flux exceeded the critical flux, which exhibited to be 20 L·m⁻²·h⁻¹ as for the membrane used in this study. The higher concentrations of turbidity and organic matter in the mixture contributed to the more significant increase of running pressure and the more serious membrane fouling. The higher temperature could lessen the membrane fouling to a certain extent. It was observed that membrane materials showed obvious effects on membrane fouling. The running pressure of Polyvinylidene Fluoride (PVDF) membrane was lower than that of chemically-modified Polyvinyl Chloride (PVC) at the same permeate flux, indicating the more promising potential of anti-pollution for PVDF membrane.