Nonlinear modelling of Activated Sludge Process

A computer simulation model for the Activated Sludge Process (ASP) of a wastewater treatment plant (WWT) is presented in this paper. The model is based on non-linear equations, which depend on wastewater concentration and flow, which values vary with time. The proposed ASM1R3 model is a reduced version of the common ASM1 model due to the fact it involves only three state variables: Ss –the dissolved biodegradable organic substrate, SNO – the dissolved nitrate nitrogen and SNH – the dissolved ammonia nitrogen. In an experimental verification the model was considered as well fitted to empirical data. The proposed model is characterized by relatively low computational complexity and can be successfully applied as integral part of the overriding control systems of the WWT plant. As a result of conducted studies it was found that it is possible to apply the ASM1R3 model to optimize and improve the WWT process parameters of the regarded plant.