Developing a framework for continuous use of models in daily management and operation of WWTPs: a life cycle approach Gu ¨ rkan Sin, Dirk J. W. De Pauw, Stefan Weijers and Peter A. Vanrolleghem ABSTRACT Gu ¨ rkan Sin Dirk J. W. De Pauw Peter A. Vanrolleghem BIOMATH, Ghent University, Coupure Links 653, B-9000 Gent, Belgium E-mail: gsi@kt.dtu.dh Stefan Weijers Waterschap De Dommel, P.O. Box 10.001, 5280 DA Boxtel, The Netherlands Peter A. Vanrolleghem modelEAU, De ´ pt. ge ´ nie civil, Universite ´ Laval, Que ´ bec QC, G1K 7P4, Canada We developed and evaluated a framework for the continuous use of dynamic models in daily management and operation of WWTPs. The overall aim is to generate knowledge and build in-house capacity for the reliable use of dynamic models in practice (within a regional water authority in The Netherlands). To this end, we have adopted a life cycle approach, where the plant model follows the different stages that make up the typical lifespan of a plant. Since this approach creates a framework in which models are continuously reused, it is more efficient in terms of resources and investment than the traditional approach where one always makes a new model for the plant whenever it is needed. The methodology was evaluated successfully at a 50,000 PE domestic EBPR plant (Haaren, The Netherlands). It is shown that the continuous use and update of models in a cyclic manner creates a learning cycle, which results in experience and knowledge generation about the plant’s modelling that accumulates and translates into improvements into the modelling quality and efficiency. Moreover, a model is now always on-the-shelf for process optimization. Key words | ASM2d, calibration, dynamic models, efficiency, life cycle, modelling, WWTP INTRODUCTION During the last decade, discharge legislation has become stricter worldwide, which among others, has caused wastewater treatment to become more complex, for instance requiring carbon, nitrogen and phosphorous removal in parallel. Understanding of these processes became increasingly challenging because of the complex interactions involved. To this end, mathematical models, and more specifically, dynamic models are regarded as useful tools to gain more insight and in-depth under- standing about the processes involved in wastewater treatment (Henze et al. 2000; Gujer 2006). So far wastewater treatment plant modelling was primarily performed at the level of universities or consulting companies (Hulsbeek et al. 2002; Langergraber et al. 2003; Melcer et al. 2003; Vanrolleghem et al. 2003; Sin et al. 2005). However, some other type of companies such as water utilities, are also starting to incorporate modelling in daily management work. One of these organizations, Waterboard De Dommel (Noord-Brabant, The Netherlands), has taken such initiative: a project was set up in order to evaluate the use of modelling as a support tool for wastewater management. In order to perform reliable modelling work in a company setting, several important requirements need to be met. Firstly, adequate expertise is required at the level of process knowledge and of modelling methodologies. Secondly, the efficiency of the classical modelling process needs to be improved. Generally speaking, there is a lack of standardization (i.e. data collection and quality check, measurement campaign set-up, model calibration, etc.) and automation (i.e. dedicated software support). Thirdly, the obtained model quality needs to be adjusted based on doi: 10.2166/wst.2008.225 1301 Q IWA Publishing 2008 Water Science & Technology—WST | 57.9 | 2008