Applied Biochemistry and Biotechnology

, Volume 109, Issue 1–3, pp 47–62

Parameter identification of thermophilic anaerobic degradation of valerate

  • Xavier Flotats
  • Birgitte K. Ahring
  • Irini Angelidaki


The considered mathematical model of the decomposition of valerate presents three unknown kinetic parameters, two unknown stoichiometric coefficients, and three unknown initial concentrations for biomass. Applying a structural identifiability study, we concluded that it is necessary to perform simultaneous batch experiments with differenitial conditions for estimating these parameters. Four simultaneous batch experiments were conducted at 55°C, characterized by four different initial acetate concentrations. Product inhibition of valerate degradation by acetate was considered. Practical identification was done optimizing the sum of the multiple determination coefficients for all measured state viariables and for all experiments simultaneously. The estimated values of kinetic parameters and stoichiometric coefficients were characterized by the parameter correlation matrix, the confidence interval, and the student's t-test at 9% significance level with positive results except for the saturation constant, for which more eperiments for improving its identifiability should be conducted. In this article, we discussekinetic parameter estimation methods.

Index Entries

Anaerobic mathematical modeling identifiability parameter estimation optimization valerate 


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Copyright information

© Humana Press Inc. 2003

Authors and Affiliations

  • Xavier Flotats
    • 1
  • Birgitte K. Ahring
    • 2
  • Irini Angelidaki
    • 3
  1. 1.Department of Environment and Soil ScienceUniversity of Lleida, Rovira Roure 177Spain
  2. 2.Department of BiotechnologyThe Technical University of DenmarkLyngbyDenmark
  3. 3.Department of Environment and ResourcesThe Technical University of DenmarkLyngbyDenmark

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