Iron(III) (hydr)oxide-mediated photooxidation of 2-aminophenol in aqueous solution: a kinetic study.

The photooxidation of 2-aminophenol in aqueous solution in the presence of an iron(III) (hydr)oxide (goethite, alpha-FeOOH), used as a heterogeneous catalyst, has been investigated at different pH (3.0-8.0) and catalyst loads (100-500 mg/l) aiming mainly at elucidating the reaction kinetics. A large experimental campaign allowed to rule out the intervention of HO radicals in the photodegradation of 2-aminophenol. The classic Langmuir-Hinshelwood equation has been used for the kinetic analysis, best estimated values of the kinetic parameters being derived by means of an optimization procedure. The dependence of reaction kinetics on the temperature in the range of 285-308K has also been investigated.