Details of talk
|Title||Analysis of the activated sludge model (number 1)|
|Presenter||Mark Nelson (University of Wollongong)|
|Author(s)||Dr Mark Nelson|
|Session||Applied Mathematics/Industrial Mathematics|
The activated sludge process is widely used in wastewater treatment plants to reduce effluent levels in contaminated wastewaters originating from both the municipal and industrial sectors. An internationally accepted standard model for The biochemical processes occurring within the reactor is the activated sludge model number 1 (ASM1). It describes nitrogen and chemical oxygen demand within suspended-growth treatment processes, including mechanisms for nitrification and denitrification. The model has been found to give a good description of the activated sludge process provided that the wastewater has been characterised in detail and is of domestic or municipal in origin. We analyse the biological treatment of a wastewater when a cascade of two reactors is used. We compare the performance of a reactor configuration using two aerobic reactors, such as used in a conventional activated sludge process, against a reactor configuration in which an anoxic reactor is placed upstream of an aerobic reactor, as is the case for the modified Ludzack-Ettinger process. A combination of direct numerical integration with continuation methods is used to investigate the steady-state behaviour of the system. In particular, we determine bifurcation values of the residence time, corresponding to branch points, that are crucial in determining the performance of the system and investigate how the use of recycle effects the removal of nitrates in the anoxic zone.