Detailed dynamic pumping energy models for optimization and control of wastewater applications

Despite the increasing level of detail in wastewater treatment process models, oversimplified energy consumption models (i.e. constant ‘average’ power consumption) are being used in optimization exercises. A new dynamic model for a more accurate prediction of pumping costs in wastewater treatment has been developed to overcome this unbalance in the coupled submodels. The model is calibrated using two case studies. The first case study concerns the centrifugal influent pumps (Nijhuis RW1-400 · 525A) of the municipal wastewater treatment plants (WWTPs) in Eindhoven (The Netherlands), governed by Waterboard De Dommel. For the second case study, concerning a centrifugal pump (Flygt, type NT3153 · 181) of the intermediate pumping station (pumping primary treated wastewater) of the Mekolalde WWTP, located in Bergara (Guipúzcoa, Spain), a model extension was necessary in order to allow a better description of the pump curve, making the model more generic. Both cases showed good agreement between the model predictions and the measured data of energy consumption. The model is thus far more accurate compared with other approaches to quantify energy consumption, paving the way towards ‘global’ process optimization and new, improved control strategies for energy reduction at WWTPs.