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-dis persion equation with a source term written principally according to the Ac tivated 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. Experimen tal methods for parameter estimation were demonstrated. The dispersion coef ficient and the oxygen transfer coefficient were estimated from tracer stud ies and off-gas measurements, respectively. Values of the kinetic and stoic hiometric coefficients estimated from batch experiments were generally foun d to agree with the default values used in the ASM1. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.