“…Samstag et al (2005) fitted Levenspiel's tank-inseries model to dye test data and reported results ranging from 53 tanks-in-series for a four-pass, 8-compartments, 40 length-to-with ration, 2.64 hr hydraulic residence time (HRT), fine-bubble aeration system, to 1 tank-in-series for a single oxidation ditch. Lei et al (2005) reported on the application of Biowin32 to simulate a plant with primary clarifiers, anaerobic digestion recycle streams and a preanoxic N-removal process. The model was calibrated based on plant data and results of 2-week intensive sampling program and its predictions were in overall good agreement with the measurements.…”