New proposed conceptual mathematical models for biomass viability and membrane fouling of membrane bioreactor

Abstract

The production and accumulation of soluble microbial products (SMP), extracellular polymeric substances (EPS) and colloidal inert compounds within a membrane bioreactor (MBR) may greatly affect the biomass viability and subsequently the permeability of the membrane. This paper aims at presenting new mathematical models of biomass viability and membrane fouling that has been conceptually developed through establishing links between these biomass parameters and operating parameters of the MBR. The proposed models can be used to predict the biomass viability and membrane fouling at any state of operation of MBR. Meanwhile, easily measurable parameters of the proposed model can also serve to estimate SMP/EPS concentration in the supernatant of MBR without the tedious and expensive measurement.

Biomass viability: An experimental study and the development of an empirical mathematical model for submerged membrane bioreactor

“…MLSS) which would obviously affect the concentration of SMP/bEPS. The currently available models (Hasar and Kinaci, 2004) including the conceptual model (Zuthi et al, 2013) proposed previously by the authors, however, can be used to explain rather qualitatively that the SMP or bEPS are correlated with the biomass viability based on the trace of soluble or colloidal components (soluble or colloidal COD) in the effluent stream.…”

“…In an earlier research, the authors (Zuthi et al, 2013) proposed modifications of the above mentioned model and proposed a new conceptual model of microbial viability which correlated SOUR with MLVSS/MLSS, and soluble/colloidal inert COD in the effluent as indicator parameters of SMP/bEPS in the bioreactor. The modified model considers the colloidal COD in the effluent as a representative parameter of bEPS in the bioreactor.…”

“…The inert COD was represented in the model mainly as an indicator parameter of SMP in bioreactor, whereas larger microbial aggregates such as bEPS and colloids were not included in the model. Although the parameters presented in the model are useful indicators of the biomass viability, these cannot be linked to the physical sub-model of the membrane fouling as the rejection efficiency of the membrane was not considered (Zuthi et al, 2013).…”

Current Status and Future Prospects of Membrane Bioreactors (MBRs) and Fouling Phenomena: A Systematic Review

“…The operational expenditures of MBRs are augmented due to control strategies associated with fouling such as air scouring, backwashing, implementation of the cross‐flow velocity (CFV), and utilization of chemicals for membrane cleaning. Obviously, the fouling event affects capital expenditures as new membranes need to be purchased in order to replace damaged membranes …”

Membrane fouling reduction and improvement of sludge characteristics by bioflocculant addition in submerged membrane bioreactor

“…The simulated data shows a dramatic accumulation of SMP after 50 days in the CMBR, and the CMBR possessed more SMP than the MBR-G during the entire operation period. Regarding pore fouling, Zuthi [50] has proposed modeling related to pore fouling of the membrane (R P ) in a submerged MBR with membrane pore size of 0.1 lm (Eq. (5)).…”