General model for biological nutrient removal activated‐sludge systems: model presentation

Abstract

The development of a general model for biological nutrient removal in activated sludge systems is discussed. The general model is a mechanistic model based on the International Association on Water Pollution Research and Control (IAWPRC) (now IAWQ) model for carbonaceous energy removal, nitrification, and denitrification (Activated Sludge Model No. 1 [ASM1]), and the Wentzel et al . (1989a and b) model for biological phosphorus removal, with a number of modifications. A fermentation process has been included for the conversion of readily biodegradable chemical oxygen demand (COD) to short‐chain fatty acids (assuming a loss of COD from the system). Hydrolysis of enmeshed slowly biodegradable COD under anoxic and anaerobic conditions has been incorporated, as well as anoxic growth of polyP organisms. These modifications and others are discussed in this paper. The matrix representation and a description of the model processes are also presented, as well as a brief outline of influent wastewater characterization.