Lag phase, dynamic alpha factor and ammonium adsorption behaviour: introduction of special activated sludge characteristics in the ASM3 + EAWAG-BioP-model.

In five full-scale municipal sequential batch reactor (SBR) wastewater treatment plants (WWTPs) indications for lag phases, a dynamic alpha factor and ammonium adsorption behaviour of the activated sludge were found. A dynamic simulation analysis of all WWTPs showed the need to implement these characteristics into the model in order to improve the calibration procedure, to meet better results for optimisation studies and even to calculate better fitting running costs including the aeration energy. Even if these effects could be characterised as minor effects, it is planned to utilise the knowledge about these effects for further optimisation of the SBR process and to achieve significant improvements.