Identification of activated sludge and wastewater characteristics using respirometric batch-experiments

This paper presents a procedure to obtain activated sludge kinetics and wastewater characteristics from respirometric batch-experiments. For identification of state variables and model parameters a modified version of the ASM no. 1 that describes the oxygen uptake rate of the nitrification process and organic matter elimination was used. It is demonstrated that the maximum nitrification rate of activated sludge and the concentration nitrifiable nitrogen, and the rapid hydrolysis rate together with the concentration slowly biodegradable organic compounds can be estimated accurately. Suggestions to improve identifiability problems are given. It is concluded that the proposed method offers possibilities to follow changes in sludge capacities, for both heterotrophic and autotrophic micro-organisms, and wastewater composition.