MODELING OF SEQUENCING BATCH REACTORS TREATING INHIBITORY AND NONINHIBITORY WASTEWATERS

A mathematical model for sequencing batch reactors (SBR) that takes in to account fill and react periods was developed and tested against exp erimental data from the literature. The Monod equation was used to des cribe microbial growth kinetics. The proposed model predicts the time dependent microbial cell and substrate concentrations during SBR treat ment of wastes. A numerical method was used to solve the governing mod el equations which comprised nonlinear unsteady-state ordinary differe ntial equations. Model simulations highlighted the importance of feed rate as a major operating parameter. For biodegradable wastes and low strength inhibitory wastes, an instantaneous fill is optimum whereas h igh strength inhibitory waste treatment is only possible with long fil l times. The model predictions compared well with experimental results reported in the literature. This model is useful for further understa nding of biological wastewater treatment kinetics by batch processes a nd may serve as a valuable design aid for practicing engineers.