Abstract
An activated sludge model for water quality management was proposed on the basic of biological reactions of heterotrophic, autotrophic and phosphate accumulating bacteria. This model is one of extensions of“Activated Sludge Model No.2 (ASM2)” presented by the IAWQ Task Group, and was made by careful checks of all of the variables, reaction processes and rate equations in ASM2. Some of variables, processes were amalgamated or excluded for simplification, while some of rate equations were replaced by more rational ones. The following are the major improved reaction models which were made in this study:
(1) Simultaneous uptake of two kinds of substrates by heterotrophic bacteria.
(2) Interactive relationship among poly-phosphate, cell internal storage product and phosphate accumu-lating bacteria.
(3) Precipitation and redissolution among phosphate, metal ions and metal phosphate.
In addition, a new denotation method was introduced for expression of reaction rate and stoichiometrical parameters, so that the model becomes more rational and simplified. Then availability of the model was verified by the comparison of observed data and simulated ones.
