Azo-dye orange II degradation by the heterogeneous Fenton-like process using a zeolite Y-Fe catalyst—Kinetics with a model based on the Fermi's equation

•Iron-containing Na-Y zeolite catalyst was prepared by ion exchange.•Catalyst is active and stable for heterogeneous Fenton-like degradation of OII.•pH and particularly reaction temperature affect considerably oxidation performance.•OII degradation follows Fermi's equation with remarkable adherence of the model.

The degradation of Orange II dye (OII) by a heterogeneous Fenton-like process was studied using a catalyst with 5 wt.% of iron after ion-exchange in a Na–Y zeolite support. The catalyst was characterized by X-ray diffraction (XRD), N2 adsorption, atomic absorption spectroscopy and X-ray fluorescence (XRF). The effect of the initial concentrations of H2O2 and OII, pH and temperature on the degradation rate of OII was investigated by carrying out experiments in a batch reactor. The OII concentration histories (i.e., concentration evolution along reaction time) were described by a simple semi-empirical kinetic model, based on the Fermi's equation, which captures simultaneously the influence of all the reaction conditions with a few adjustable parameters. The adherence of the model to the data was remarkable, and the effect of the operating conditions on the obtained fitting parameters – apparent rate constant and transition time – was analyzed.

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