Fundamental nonlinearities of the reactor-settler interaction in the activated sludge process
Autor: | Sebastian Farås, Stefan Diehl |
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Rok vydání: | 2012 |
Předmět: |
Engineering
Environmental Engineering Steady state Partial differential equation Sewage business.industry Simulation modeling Models Theoretical Waste Disposal Fluid Clarifier Volumetric flow rate Nonlinear system Activated sludge Bioreactors Control theory Computer Simulation Uniqueness business Process engineering Water Pollutants Chemical Water Science and Technology |
Zdroj: | Water science and technology : a journal of the International Association on Water Pollution Research. 66(1) |
ISSN: | 0273-1223 |
Popis: | The activated sludge process can be modelled by ordinary and partial differential equations for the biological reactors and secondary settlers, respectively. Because of the complexity of such a system, simulation models are most often used to investigate them. However, simulation models cannot give general rules on how to control a complex nonlinear process. For a reduced-order model with only two components, soluble substrate and particulate biomass, general results on steady-state solutions have recently been obtained, such as existence, uniqueness and stability of solutions. The aim of the present paper is to utilize those results to formulate some implications of practical importance. In particular, strategies are described for the manual control of the effluent substrate concentration subject to the constraint that the settler is maintained in normal operation (with a sludge blanket in the thickening zone) in steady state. Such strategies contain how the two control parameters, the recycle and waste volumetric flow ratios, should be chosen for any (steady-state) values of the input variables. |
Databáze: | OpenAIRE |
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