Approaches to modeling nutrient dynamics: ASM2, simplified model and neural nets

The Activated Sludge Model No. 2 (ASM2) is applied to modeling process dyna mics (nitrogen and phosphorus) in a sequencing batch reactor (SBR). Additio nally, simplified process model (SPM) and neural net (NN) approaches are pr oposed and introduced into the SBR modeling. Simulation results show that t he ASM2 can offer better predictions and explanations to certain batches of SBR data than those of the SPM; frequent calibrations, however, are needed . The hybrid SPM and NN model show model robustness and improve model predi ctions. The results of this study demonstrate that the ASM2 is good for det ailed process simulations while the proposed hybrid approach is more suitab le for on-line prediction and process control. (C) 1999 IAWQ Published by E lsevier Science Ltd. All rights reserved.