Dynamical Modelling and Simulation of Wastewater Filtration Process by Submerged Membrane Bioreactors

A mathematical model was developed for the filtration process and the influence of aeration on Submerged Membrane Bioreactors. The dynamics of sludge attachment to and detachment from the membrane, in relation to the filtration and a strong intermittent aeration, were included in the model. The influence on the membrane fouling of intermittent aeration injected on the membrane surface, and its synchronization with intermittent filtration, were studied numerically and experimentally. For the evaluation of filtration cake development, the assumption of the presence of two cake layers (one dynamic and the other stable) was considered. The model development and simulation focused on the description of existing relationships among important system variables like mixed liquor suspended solids concentration, aeration, temperature of the sludge suspension, transmembrane pressure, and the fouling increase during the filtration process. The model obtained offers the possibility of improving the design configuration and operation strategies of Submerged Membrane Bioreactors in wastewater treatment, and it allows the of aeration-filtration cycles to be optimized.