Modeling and simulation of membrane bioreactors by incorporating simultaneous storage and growth concept: an especial attention to fouling while modeling the biological process

Abstract

The major obstacle for membrane bioreactors (MBRs) to become a widely applicable technology is the membrane fouling. Despite the fact that the fouling is inevitable, understanding of the inherent mechanisms and subsequent integrated modeling of the process seems greatly helpful for optimization and control. Several researches have shown the importance of extra-cellular polymeric substances (EPS) their role in explaining the two-step with sudden jump in TMP vs. time. But, the crucial point remains about the prediction of the EPS concentration in the dynamic MBR sludge matrix and the research attention becomes bit more on biological behavior of the sludge matrix in order to have ‘an integrated complete dynamic model’ describing both filtration and biological behavior simultaneously. Moreover, on account of operational and fundamental difference from conventional wastewater treatment processes, MBRs possess distinct biological dynamics and hence the activated sludge models (ASMs: ASM1, ASM3, etc. [4]) in their original form are not expected to be workable. Therefore, the two-fold idea has been suggested and used for simulation herein are (i) improved version of ASM3 as suggested by Sin et al. [16] seems promising in order to explain the distinct MBR biological process dynamics, and (ii) EPS model which has a strong urge to be used as input to fouling model. The notion of ‘complete model’ provides a platform to infuse the researches from two different fields viz. biological process modeling and filtration modeling for MBRs application in a harmonized way and hence provokes interconnected investigations from both the fields.