Model Based Optimisation of an Industrial Wwtp: Dealing with Wastewater Mixtures from Different Production Facilities

Industrial WWTP’s have to provide a 100 % reliability and availability for the discharging facilities (Bury et al., 2002). The industrial WWTP in this study treats wastewater the same way as most municipal WWTP, i.e. with an activated sludge process. However, some differences can be pointed out. The first problematic difference is that the composition of industrial wastewater fluctuates considerably more than domestic wastewater because of the variations in the production schedule of the facilities discharging to the WWTP. This hinders the optimisation of the WWTP considerably. A second problem is that some components occur in the industrial wastewater that are normally not present in domestic wastewater. This makes it necessary to extend the normally applied Activated Sludge Model Nr.1 (ASM1) (Henze et al., 2000). The aim of this study is twofold. The first step is the development and calibration of a model for the industrial WWTP. This development and calibration of the model was based on the calibration protocol developed by Petersen et al. (2002b). The protocol however had to be extended to take into account the specific components in the wastewater. The second step of the study is the use of the model for optimisation of the WWTP. By simulating with the calibrated and validated model it could for example be shown how a 20 % reduction of the effluent degradable COD concentration could be achieved. This case study shows how the combination of both steps can lead to fast modelling and optimisation of an industrial WWTP.