Unstationary Film Model for the Determination of Absolute Gas-Liquid Kinetic Rate Constants: Ozonation of Acid Red 27, Acid Orange 7, and Acid Blue 129

Abstract

A method for the determination of absolute kinetic rate constants is proposed using an unstationary film model. This methodology avoids the experimental determination of parameters like the enhancement factor or the Hatta number which are usually model-dependent. The mathematical model is general for gas-liquid systems with irreversible second order reactions. An optimization procedure based on artificial neural networks is used to estimate the initial guess of the parameters and the subsequent application of Gauss-Newton algorithm for the final nonlinear parameter estimation. The model is tested with the ozonation reaction of Acid Red 27, Acid Orange 7 and Acid Blue 129. The second-order kinetic rate constants for the direct reaction with O₃ are 1615 ± 93, 609 ± 83, and 49 ± 2 M⁻¹s⁻¹, respectively.

Keywords:

• Ozone
• Azo Dyes
• Acid Red 27
• Acid Orange 7
• Acid Blue 129
• Ozonation
• Mathematical Modeling
• Absolute Kinetic Rate Constant Determination
• Artificial Neural Networks

ACKNOWLEDGMENTS

JF acknowledges the support of the doctoral fellowship from the Universitat Politècnica de València (UPV-PAID-FPI-2010-04).