Chemical Model of Oxidation

The oxidation process consists of direct and indirect reactions which can occur at the same time. A second order rate equation is commonly accepted for both reaction pathways. So that the oxidation of the model compound M can be described as the sum of the two reaction pathways as follows  

Often the reaction is simplified to pseudo-first order  

The reaction rate coefficient k is dependent on the direct (kD) and indirect (kR) oxidation rate constants as well as the ozone and OH° concentrations. However, it is assumed to be constant with respect to time. 

In waste water oxidation, mass transfer is often limiting so that 

This leads to largely differing areas of interest for the two fields. Models to determine the concentration of the OH0 as a function of the water matrix are needed in drinking water applications, while models that incorporate the influence of the hydrodynamics and mass transfer on the reaction rate are necessary for waste water applications. 

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