Abstract: The objective of this work was to study and numerically evaluate the effect of various operation conditions like location of immersed membrane module and aeration design on the hydrodynamics in a pilot scale bubble column with a membrane module. The effects of the membrane module orientation can be more clearly demonstrated by comparing the gas holdup at different cross-sections along the column height and analyzing the shear stress distribution on the membrane surface by CFD. However, the simulation of the flow behavior surrounding the membranes requires high mesh resolutions and hence a large number of elements. The numerical simulation was done with Ansys CFX, using the k-ɛ model with scalable wall function for turbulence, high resolution advection scheme and second order backward Euler transient scheme for solving the Navier-Stokes equations. The influence of the flow on sludge accumulation is estimated by shear strain rate of the phases. A CFD model was developed which accounts for aeration and membrane configurations. The numerical results of the velocity, pressure and volumetric fraction distributions for the simulations at different geometric characteristics of the membrane are presented and analyzed. The research demonstrates the capability of using CFD to optimize the design of the membrane module, aeration system and membrane bubble column.