Parameter estimation procedure for complex non-linear systems: calibrationof ASM No.1 for N-removal in a full-scale oxidation ditch

When applied to large simulation models, the process of parameter estimatio n is also called calibration. Calibration of complex non-linear systems, su ch as activated sludge plants, is often not an easy task. On the one hand, manual calibration of such complex systems is usually time-consuming, and i ts results are often not reproducible. On the other hand, conventional auto matic calibration methods are not always straightforward and often hampered by local minima problems. In this paper a new straightforward and automati c procedure, which is based on the response surface method (RSM) for select ing the best identifiable parameters, is proposed. In RSM, the process resp onse (output) is related to the levels of the input variables in terms of a first- or second-order regression model. Usually, RSM is used to relate me asured process output quantities to process conditions. However, in this pa per RSM is used for selecting the dominant parameters, by evaluating parame ters sensitivity in a predefined region. Good results obtained in calibrati on of A SM No.1 for N-removal in a full-scale oxidation ditch proved that t he proposed procedure is successful and reliable.