Abstract
We consider a three-dimensional deterministic control model of the process of aerobic wastewater biotreatment. For this model, we formulate and solve two optimal control problems, each of which has a corresponding minimizing functional. For the first problem, the functional is a weighted sum of the pollutant concentration at the end of a fixed time interval and the cumulative biomass con- centration over the interval. For the second problem, the functional is a weighted sum of the pollutant concentration at the end of the time interval and the cumulative oxygen and biomass concentra- tions over the interval. In order to solve these problems, we apply the Pontryagin Maximum Principle. The switching functions are analytically investigated and uniquely determine the type of the op- timal controls for the considered problems. Their properties allow the simplification of the optimal control problems to that of finite- dimensional constrained minimization. Numerical solutions of the optimal control problems are also provided.
References
Bondarenko, N.V.; Grigorieva, E.V.; Khailov, E.N. (2010) “Attainable set of three-dimensional nonlinear system describing the wastewater treatment process”, in: Yu.S. Osipov & A.V. Kryazhimskii (Eds.) Problems of Dynamical Control, 5, MAX Press, Moscow: 28–41.
Gomez, J.; de Gracia, M.; Ayesa, E.; Garcia-Heras, J.L. (2007) “Mathematical modelling of autothermal thermophilic aerobic digesters”, Water Research 41(5): 959–968.
Grigorieva, E.; Bondarenko, N.; Khailov, E.; Korobeinikov, A. (2012) “Finite-dimensional methods for optimal control of autothermal thermophilic aerobic digestion”, in: K.Y. Show & X. Guo (Eds.) Industrial Waste, InTech, Croatia: 91–120.
Grigorieva, E.V.; Bondarenko, N.V.; Khailov, E.N.; Korobeinikov, A. (2012) “Three-dimensional nonlinear control model of wastewater biotreatment”, Neural, Parallel, and Scientific Computations 20: 23–36.
Grigorieva, E.V.; Khailov, E.N.; Korobeinikov, A. (2012) “Reduction of the operation cost via optimal control of an industrial wastewater biotreatment process”, in: http://jointmathematicsmeetings.org/amsmtgs/2138 abstracts/1077-g5-1378.pdf.
Krasnov, K.S.; Vorob’ev, N.K.; Godnev, I.N.; et al. (1995) Physical Chemestry 2. Vysshaya Shkola, Moscow.
Lee, E.B.; Marcus, L. (1967) Foundations of Optimal Control Theory. John Wiley & Sons, New York.
Pontryagin, L.S.; Boltyanskii, V.G.; Gamkrelidze, R.V.; Mishchenko, E.F. (1962) Mathematical Theory of Optimal Processes. John Wiley & Sons, New York.
Rojas J.; Burke, M.; Chapwanya, M.; Doherty, K.; Hewitt, I.; Korobeinikov, A.; Meere, M.; McCarthy, S.; O’Brien, M.; Tuoi, V.T.N.; Winstenley, H.; Zhelev, T. (2010) “Modeling of autothermal thermophilic aerobic digestion”, Mathematics-in-Industry Case Studies 2: 34–63.
Vasil’ev, F.P. (2002) Optimization Methods. Factorial Press, Moscow.
Comments
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Copyright (c) 2013 Revista de Matemática: Teoría y Aplicaciones