Experimental Validation of a Hydrodynamic CFD Model of a Hollow Fiber MBR Using Shear Intensity Measurements

The main drawback of MBR systems is the fouling of the membrane, which is decrease and/or prevented through gas sparging. However, gas sparging practices are based on rules of thumb or a trial-and-error approaches which are tedious, very time-consuming and do not necessarily provide optimal fouling control. Therefore, dedicated experiments are needed to fully understand the hydrodynamics of this two-phase flow. This work focus on the validation of extensive experiments using a pilot-scale hollow fiber GE-Zenon submerged MBR against computational fluid dynamics (CFD). It was found that the order of magnitude from the CFD model is similar compared to experimental data in magnitude based on the shear intensity contours and the overall average. However, some differences in the distribution and magnitude of shear intensity throughout the pilot-scale submerged MBR system were observed. Cumulative frequencies were considered to compare the CFD results and the experimental data. It was found that below the 50 th percentile, the CFD and experimental data was similar (error less than 8 %). At higher shear intensity, the differenced between the simulation and the experimental data increase up to 17 %. These were likely due to the approximations made in developing the CFD model (i.e. rigid membrane modules, no water-air air flow through the fibers). Although further improvements are needed to use the CFD model for optimization, the results from the present study are promising.