Analyses and modelling of filtration processes in MBR and test cells

[4] for dead-end cake filtration and pore blockage and the model of Fradin and Field [3] for crossflow cake filtration. Although the filterability of activated sludge was determined in a crossflow test cell, we usually observed the mechanism of dead-end cake filtration. The crossflow filtration mechanism, which is found in MBRs with immersed membrane module, was attained only with additional aeration. Therefore standardized and aerated test cell experiments are required to characterize the filterability of suspensions. In addition, the filtration mechanisms at constant DP are different from those at constant flux. At design stage of a membrane unit, the characterisation of the suspension should be done at the same operating conditions as in the plant.