Characterization of Wastewater for Modelling of Activated Sludge Processes

The fractionation of organic matter in the various parts which are used for mathematical modelling is discussed. The fractions include inert soluble, readily biodegradable, rapidly hydrolysable, slowly hydrolysable, biomass and inert suspended material. Methods for measuring are also discussed. Fractionation of biomass in wastewater and in activated sludge is difficult at present, as methods are only partly developed. Nitrogen fractions in wastewater are mainly inorganic. The organic nitrogen fractions are coupled to the organic COD fractions. The fractions of COD, biomass and nitrogen found in a specific wastewater seem to be constant even when concentrations vary. Wastewater input to sewers and the sewer transport system significantly influences the raw wastewater composition at treatment plants.</jats:p

River water quality model no. 1 (RWQM1): II. Biochemical process equations

In this paper, biochemical process equations are presented as a basis for water quality modelling in rivers under aero-bic and anoxic conditions. These equations are not new, but they summarise parts of the development over the past 75 years. The primary goals of the presentation are to stimulate communication among modellers and field-oriented researchers of river water quality and of wastewater treatment, to facilitate practical application of river water quality modelling, and to encourage the use of elemental mass balances for the derivation of stoichiometric coefficients of biochemical transformation processes. This paper is part of a series of three papers: In the first paper, the general modelling approach is described; in the present paper, the biochemical process equations of a complex model are presented; and in the third paper, recommendations are given for the selection of a reasonable submodel for a specific application

A general model for single-sludge wastewater treatment systems

In 1983 IAWPRC formed a task group to facilitate the application of practical models to the design and operation of biological wastewater treatment systems. This paper presents an outline of the model developed for single-sludge systems performing carbon oxidation, nitrification and denitrification. The model includes seven fundamental processes: aerobic growth of heterotrophic biomass, anoxic growth of heterotrophic biomass, aerobic growth of autotrophic biomass, decay of heterotrophic biomass, decay of autotrophic biomass, hydrolysis of entrapped particulate organic matter, and hydrolysis of entrapped organic nitrogen. The model is presented in the form of a matrix which utilizes stoichiometric coefficients to couple the components in the model with the process rate expressions acting upon them.</jats:p