ABSTRACT
Plants ............................................................................................... 295 11.4 Model Extensions Focused on P Removal ............................................. 296 11.5 Modeling Sedimentation Processes ........................................................ 298
11.5.1 Gravitational Settling .................................................................... 298 11.5.2 Settler Models ................................................................................. 299
11.6 Anaerobic Digester Models ......................................................................303 11.6.1 Anaerobic Digestion Principles ...................................................303 11.6.2 Anaerobic Digestion Models ........................................................305 11.6.3 ADM1 Limitations .........................................................................308
11.7 Current WWTP Model Development Issues .........................................308 11.7.1 Plant-Wide Models .........................................................................309 11.7.2 Good Modeling Practice ............................................................... 310 11.7.3 Uncertainty and Sensitivity Analysis ......................................... 311
11.8 Guidelines for Application of WWTP Models ....................................... 312 References ............................................................................................................. 316 Further Reading-Model Extensions Focused on N-Removal .................... 321 Further Reading-Bio-P Model Development ............................................... 322
Wastewater systems cover a range of essential technologies to signicantly reduce the impact of household and industrial wastewater on receiving water quality. Biological wastewater treatment processes are often the key to achieving wastewater purication against an acceptably low cost. One of the most widespread biological wastewater purication technologies is the activated sludge process, where the incoming wastewater is mixed with a concentrated bacterial biomass suspension (the activated sludge), which degrades the pollutants. The earliest activated sludge systems were mainly concerned with the removal of organic carbon substances from the wastewater, which could be obtained rather easily by simple process designs. However, over the years more stringent efuent standards, especially for the nutrients nitrogen (N) and phosphorus (P), has resulted in signicant modi-cations to the design and operation of activated sludge plants to make the treatment plants suited for biological N and P removal as well.
