THE ACTIVATED-SLUDGE PROCESS .4. APPLICATION OF THE GENERAL KINETIC-MODEL TO ANOXIC AEROBIC DIGESTION OF WASTE ACTIVATED-SLUDGE

This paper discusses the application of the general activated sludge model as set out by P. L. Dold et al. and extended by A. C. Van Haandel et al. to anoxic-aerobic digestion of waste activated sludge. The laboratory scale experimental investigation comprised a 6 day sludge age activated sludge process, the waste sludge from which was fed to a number of digesters. Both theoretical simulations and experimental data indicate that the rate of volatile solids destruction is not affected by the incorporation of anoxic cycles and the specific denitrification rate constant in a digester is about two-thirds of that in the secondary anoxic reactor of the single sludge activated sludge system; this allows definition of a fourth denitrification rate constant for the anoxic-aerobic digester.