Comparison and database development of four recent ASM3 model extensions

In the last decade, many Activated Sludge Model No. 3 (ASM3) extensions were proposed to adopt new concepts such as simultaneous storage and growth of heterotrophic organisms and two-step nitrification-denitrification processes. From these ASM3 model extensions, four are included in this study: ASM3 with two-step nitrification-denitrification, ASM3 for simultaneous autotrophic and heterotrophic storage-growth, ASM3 extension for two-step nitrification-denitrification, and ASM3 for simultaneous storage-growth and nitrification-denitrification. The four models are analyzed and compared to the original ASM3 model with respect to the modeling concepts adopted, the process kinetic rates modified, and the kinetic parameters and stoichiometric coefficients introduced. A new schematic representation of the modeling concepts concerning the organisms' activities is introduced. A database of all parameters and coefficients of the four considered model extensions is developed using a unified notation system to reduce effort and confusion of the future researchers using their values as initial calibration or guidance values. Finally, the four models and the original ASM3 model are implemented using the parameters' values from the developed database, then the simulation results are compared with actual field measurements. © 2016 American Society of Civil Engineers.