Model development and parameter estimation for a hybrid submerged membrane bioreactor treating Ametryn

A lab-scale membrane bioreactor (MBR) was used to remove Ametryn from synthetic wastewater. It was found that concentrations of MLSS and extra-cellular polymeric substances (EPS) in MBR mixed liquor fluctuated (production and decay) differently for about 40 days (transition period) after the introduction of Ametryn. During the subsequent operations with higher organic loading rates, it was also found that a low net biomass yield (higher death rate) and a higher rate of fouling of membrane (a very high rate during the first 48 h) due to increased levels of bound EPS (eEPS) in MBR mixed liquor. A mathematical model was developed to estimate the kinetic parameters before and after the introduction of Ametryn. This model will be useful in simulating the performance of a MBR treating Ametryn in terms of flux, rate of fouling (in terms of transmembrane pressure and membrane resistance) as well as treatment efficiency.

► A mathematical model was developed for a lab-scale membrane bioreactor (MBR) treating Ametryn (herbicide).
► Model describes accumulation, detachment and consolidation of bound EPS (eEPS) on the membrane surface.
► The model was able to predict the behaviour of MBR with and without the addition of Ametryn.
► For an organic loading rate of 2.15 g-COD/L/day with Ametryn, biomass yield reduced by 34% and death rate increased by 26%.