Reaction kinetics for the degradation of phenol and chlorinated phenols using Fenton's reagent

Fenton's reaction is an advanced treatment technology often used for the removal of hazardous and refractory organic compounds from industrial wastewaters. It can effectively be used to degrade phenol and chlorophenols. The initial contaminant concentrations as well as the concentration of hydrogen peroxide and ferrous ions in aqueous solution have a significant effect on the effective degradation of contaminants. For a particular concentration of initial substrate in solution there should be an optimum level of ferrous ion concentration in the reaction medium. Based on experimental observations, a probable mechanism for Fenton's degradation kinetics has been proposed and a rate equation developed. From the rate expression, OH· radical reaction rate constants for the degradation of three compounds—phenol and o‐ and p‐chlorophenols—in Fenton reaction were calculated to have values of 2.53 × 107, 2.38 × 107, and 2.45 × 107 m3 mol−1 s−1, respectively.