A general model of the activated sludge reactor with dispersive flow—I. model development and parameter estimation

A general dynamic model, including biological processes, hydraulics, oxygen transfer and temperature, was developed for the activated sludge reactor. Transport of wastewater constituents was described by the 1-D advection–dispersion equation with a source term written principally according to the Activated Sludge Model No. 1 (ASM1). Oxygen transfer was strongly related to the air flowrate and this feature was included in the oxygen mass balance. The temperature model was based on a heat balance of the reactor. Experimental methods for parameter estimation were demonstrated. The dispersion coefficient and the oxygen transfer coefficient were estimated from tracer studies and off-gas measurements, respectively. Values of the kinetic and stoichiometric coefficients estimated from batch experiments were generally found to agree with the default values used in the ASM1.