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This study investigates the impact of air sparging and the system configuration on the permeate flux in a submerged hollow fiber membrane system. The study was aimed at establishing the magnitude of the contribution from single phase cross-flow, dual phase cross-flow (air sparged), and air slug induced physical contact between the membrane fibers on the resulting permeate flux. The bench scale submerged membrane system used in the study consisted of a constant vacuum system (site vacuum line, vacuum regulator, two vacuum equilibration chambers), a permeate collection and measurement system (digital scale and data logger), a submerged membrane system (membrane tank, baffle and membrane module), and an air sparging system (air line, air flow controller, peripheral and central aerators). All experiments were performed at a constant transmembrane pressure and the permeate flux was monitored overt time. The results indicate that single phase bulk cross-flow does not significantly contribute to maintaining a high permeate flux in a submerged hollow fiber membrane system. On the other hand, the interactions between sparged air bubbles and the membrane fibers significantly contribute to maintaining a high permeate flux. The physical contact between the membrane fibers also significantly contributes to maintaining a high permeate flux. The reduction in the permeate flux over time could be characterized by an initial short period of fast permeate flux decline, followed by a longer period of slower permeate flux decline for all experimental conditions investigated. The hydrodynamic conditions and the system configuration had a significant impact on the pseudo-steady state permeate flux. The pseudo steady state permeate flux that could be maintained in an air-sparged system was 20 to 60% higher that which could be maintained without air sparging. By promoting the physical contact between membrane fibers, it was possible to further increase the pseudo steady state permeate flux by 10 to 20%. The pseudo steady state permeate flux increased with the extent of air sparging. However, a plateau was observed above which an incremental increase in air sparging intensity was not accompanied by an increase in the pseudo steady state permeate flux. The physical contact between the membrane fibers enhances the permeate flux by eroding the foulant layer that forms on a membrane surface. Includes 6 references, table, figures.