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Research Article | DOI: https://doi.org/ISSRR-RA-25-015

Analysis and Control of the Activated Sludge Model (ASM1)

Lakshmi. N. Sridhar

Chemical Engineering Department University of Puerto Rico Mayaguez,United States of America

*Corresponding Author: Lakshmi. N. Sridhar, Chemical Engineering Department University of Puerto Rico Mayaguez

Citation: Lakshmi. N. Sridhar (2025). Analysis and Control of the Activated Sludge Model (ASM1), J International Social Science Research and Review. 2 (3), DOI: ISSRR-RA-25-015.

Copyright: Lakshmi. N. Sridhar, et al © (2025). This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Received: 24 July 2025 | Accepted: 31 July 2025 | Published: 01 August 2025

Keywords: activated sludge model (ASM1); bifurcation; optimization; control

Abstract

Elimination of contamination in wastewater is crucial to ensure the well-being and health of the population. The activated sludge process is highly nonlinear, and many factors must be taken into account to ensure that the process is conducted most efficiently. Bifurcation analysis is a powerful mathematical tool used to deal with the nonlinear dynamics of any process. Several factors must be considered, and multiple objectives must be met simultaneously.  Bifurcation analysis and multiobjective nonlinear model predictive control (MNLMPC) calculations are performed on the activated sludge model (ASM1). The MATLAB program MATCONT was used to perform the bifurcation analysis. The MNLMPC calculations were performed using the optimization language PYOMO   in conjunction with the state-of-the-art global optimization solvers IPOPT and BARON. The bifurcation analysis revealed the existence of branch points in the model. The branch points were beneficial because they enabled the multiobjective nonlinear model predictive control calculations to converge to the Utopia point in both problems, which is the most beneficial solution. A combination of bifurcation analysis and multiobjective nonlinear model predictive control for the activated sludge model (ASM1) is the main contribution of this paper.

References

  1. Henze, M., C.P.L. Grady Jr., W. Gujer, G.V.R. Marais, T. Matsuo (1987) A general model for single-sludge wastewater treatment systems, Water Res. 21 (5) 505_515.
    View at Publisher | View at Google Scholar
  2. Henze, M.(1995), W. Gujer, T. Mino, T. Matsuo, M.C. Wentzel, G.V.R. Marais, Activated sludge model no 2. IAWQ Scientific and Technical Reports 3, IAWQ, .
    View at Publisher | View at Google Scholar
  3. Henze, M. (1999), Modelling of aerobic wastewater treatment processes, in: Environmental Processes I: Wastewater Treatment, second edition, in: H.-J. Rehm, G. Reed (Eds.), Biotechnology: A Multi-volume comprehensive Treatise, vol. 11a, Wiley-VCH, , pp. 417_427.
    View at Publisher | View at Google Scholar
  4. Gujer, W., M. Henze, M. Loosdrecht, T. Mino (1999), Activated sludge model No 3, Water Sci. Technol. 39 (1) 183_193.
    View at Publisher | View at Google Scholar
  5. Fikar, M., B. Chachuat, M.A. Latifi (2005) , Optimal operation of alternating activated sludge processes, Control Eng. Pract. 13 853_861.
    View at Publisher | View at Google Scholar
  6. Yoon, S. H., S. Lee (2005), Critical operational parameters for zero sludge production in biological wastewater treatment processes combined with sludge disintegration, Water Res. 39 3738_3754.
    View at Publisher | View at Google Scholar
  7. Nelson, M. I., H.S. Sidhu (2009), Analysis of the activated sludge model (number 1), Applied Mathematics Letters, Volume 22, Issue 5, Pages 629-635, ISSN 0893-9659, https://doi.org/10.1016/j.aml.2008.05.003.
    View at Publisher | View at Google Scholar
  8. Dhooge, A., Govearts, W., and Kuznetsov, A. Y.,(2003) MATCONT: “A Matlab package for numerical bifurcation analysis of ODEs”, ACM transactions on Mathematical software 29(2) pp. 141-164 .
    View at Publisher | View at Google Scholar
  9. Dhooge, A.,W. Govaerts; Y. A. Kuznetsov, W. Mestrom, and A. M. Riet (2004), “CL_MATCONT”; A continuation toolbox in Matlab,
    View at Publisher | View at Google Scholar
  10. Kuznetsov,Y.A(1998). “Elements of applied bifurcation theory” .Springer,NY, .
    View at Publisher | View at Google Scholar
  11. Kuznetsov,Y.A.(2009).”Five lectures on numerical bifurcation analysis” ,Utrecht University,NL., 2009.
    View at Publisher | View at Google Scholar
  12. Govaerts, w. J. F.(2000), “Numerical Methods for Bifurcations of Dynamical Equilibria”, SIAM, .
    View at Publisher | View at Google Scholar
  13. Flores-Tlacuahuac, A. Pilar Morales and Martin Riveral Toledo (2012); “Multiobjective Nonlinear model predictive control of a class of chemical reactors” . I & EC research; 5891-5899
    View at Publisher | View at Google Scholar
  14. Hart, William E., Carl D. Laird, Jean-Paul Watson, David L. Woodruff, Gabriel A. Hackebeil, Bethany L. Nicholson, and John D. Siirola(2017) . “Pyomo – Optimization Modeling in Python” Second Edition. Vol. 67.
    View at Publisher | View at Google Scholar
  15. Wächter, A., Biegler, L.(2006) “On the implementation of an interior-point filter line-search algorithm for large-scale nonlinear programming”. Math. Program. 106, 25–57.
    View at Publisher | View at Google Scholar
  16. Tawarmalani, M. and N. V. Sahinidis,(2005) “A polyhedral branch-and-cut approach to global optimization”, Mathematical Programming, 103(2), 225-249,
    View at Publisher | View at Google Scholar
  17. Sridhar LN. (2024) Coupling Bifurcation Analysis and Multiobjective Nonlinear Model Predictive Control. Austin Chem Eng. 2024; 10(3): 1107.
    View at Publisher | View at Google Scholar
  18. Upreti, Simant Ranjan (2013); Optimal control for chemical engineers. Taylor and Francis.
    View at Publisher | View at Google Scholar
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