Keywords: wastewater treatment, activated sludge, bifurcation, nonlinear dynamics, treatment efficiency, reaction engineering, stability, modelling, two-reactor cascade, single tank, aeration, sludge bacteria, sewage bacteria
Performance comparison between a two-reactor cascade and a single tank in an activated sludge wastewater treatment process
We investigate a model for the treatment of wastewater in the activated sludge process. The process is based on the aeration of wastewater with flocculating biological growth, followed by the separation of treated wastewater from biological growth. The biochemical model consists of two types of bacteria: sludge bacteria and sewage bacteria; and two types of ciliated protozoa: free-swimming ciliates and ciliates attached to sludge flocs. A combination of steady-state analysis, path following techniques and numerical integration of the governing equations are used to compare the performance for a single tank system with that of a two-reactor cascade.