A complete kinetic model of Ozone decomposition in aqueous solutions as a function of pH under acidic to neutral conditions

LOVATO MARTÍN CASSANO

Berlín, Alemania

Congreso; AOP5 - 5th IWA-Conference on Oxidation Technologies for Water and Wastewater Treatment; 2009

The Ozone decomposition reaction in water, operated under acidic to neutral conditions was studied. Using a proposed 18 steps kinetic scheme existing in the literature, from the reported values compiled in the bibliography, it was not possible to find a consistent set of kinetic constants to represent the experimental data, the reason being that most of the values were obtained under very different operating conditions, particularly the pH. Resulting from a parametric sensitivity analysis, a correction introduced in one kinetic constant (that was made to depend on a simple analytical function of the reacting medium pH) a reliable, 18 steps, kinetic model, valid for the pH range from 2 to 7 was found. The semi-empirical model has shown very good agreement with the experimental results. It was also found that the kinetics has a strong dependence on the concentration of hydrogen peroxide formed at low concentrations, as a stable reaction by-product