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. (C) 2000 Elsevier Science Ltd. All rights reserved.