It has been established that slug bubbling is an effective strategy to control fouling in flat sheet MBRs (FSMBR). Following prior work that ascertained optimal values of plate thickness and channel gaps, the focus here is on optimizing aerator spacing for operation under a range of aeration rates. The overall objective is to enhance fouling control of commercial-scale FSMBRs through optimization of the bubble distribution and the intensity of the induced shear stress. Three-dimensional Computational Fluid Dynamics (CFD) simulation was used to predict the aeration process of bubble coalescence, development, split and distribution into channels between every membrane pair. The bubble features and behavior were analyzed and compared with experimental measurements and substantial agreement was obtained. The aeration inlet conditions, including aerator spacing, were varied to control the slug bubbling process. The combination of aeration inlet velocity at 11 m/s and aerator spacing of 156 mm was verified to be an optimal condition, which would give a combination of uniform distribution of slug bubbles between the plates, high induced shear stress at the membrane surface and an economic air consumption. The aeration consumption for 100 sheets of membranes would be reduced by 47% compared to the conventional industrial norm.

CFD and experiment observations on bubble coalescence and development into large-sized bubble below the base of the membrane plates for rates of 17 m/s and 5 m/s.