An integrated modeling of stoichiometry and biokinetics of anaerobic processes

The objective of this paper was to present an integrated modeling approach to biokinetics and stoichiometry of anaerobic treatment processes. A software system has been developed to calculate bacterial yield coefficients from stoichiometry under different anaerobic bioprocess conditions. Kinetic constants, i.e., the reaction rate constant and Monod half-velocity coefficient, were determined from batch experimental data using Conreg, a software system for constrained nonlinear regression. Additional experiments were performed to evaluate the usefulness of the Inhibition Coefficient model to predict toxicity of ammonia and methylene chloride in anaerobic batch systems. The integrated approach to biokinetics and stoichiometry and the software developed for this purpose should help engineers quickly evaluate a wide variety of design options for anaerobic treatment systems under both toxic and non-toxic conditions. Other useful applications include prediction of natural rates of methane (a gas causing global warming) formation in rice paddies.