ASM1 limitations for modeling of wastewater treatment processes

In modern wastewater reactor technology dynamic modelling proved to be a va luable tool for the simulation of wastewater treatment performance, especia lly in cases of problematic inflow characteristics and no optimal process c onditions. Due to stringent EU legislation the Domzale-Kamnik WWTP of 200,0 00 PE is confronted with the need to upgrade the plant in the sense of nutr ient removal. As the full-scale plant is also subject to changing process conditions, a C STR pilot plant of 15 liters was installed. The system was operated in the single sludge mode at the specified process conditions (temperature, dissol ved oxygen, flow, recycle ratio), and was fed with artificial wastewater. T he effluent composition (organic nitrogen, ammonium, nitrate, COD), some st oichiometric and kinetic parameters, and operation parameters of the pilot plant were determined in the laboratory by standard laboratory methods. The se results served as input parameters for the calibration of the steady-sta te model based on real conditions according to IAWQ model No. 1. The dynamic response to a step disturbance of the input flow was measured a nd comparison between dynamic response of the calibrated ASM1 model and exp erimental data is represented. The disagreement between the experimental an d by model predicted results can be explained with ASM1 limitations.