Hydrodynamic Mathematical Modelling of Aerobic Plug Flow and Non ideal Flow Reactors: A Critical and Historical Review

Existing mathematical models of wastewater treatment plants focus primarily on the bioconversion processes and often do not cope with the reactor hydrodynamics. However, in the literature several aerobic plug flow bioreactors with both kinetics modelling and hydrodynamics description are reported. The authors review mathematical models of aerobic plug flow reactors, such as activated sludge reactors, fluidized bed reactors, biofilters, and trickling filters focusing on their hydrodynamic approach and on the role of the reactor configuration on the process performance. For each reactor type the following modelling approach is compared: (a) ideal model, such as plug flow or complete mixed, (b) tank in series model, (c) dispersion model and (d) computational fluid dynamic model.