Goethite as an efficient heterogeneous Fenton catalyst for the degradation of methyl orange

The heterogeneous Fenton process was employed to degrade methyl orange (MO) using goethite as the catalyst. The catalyst stability was evaluated by measuring color removal in three successive cycles. The goethite samples before and after the reaction were characterized by XRD, SEM and FUR techniques. The effect of major parameters, including pH, H2O2 concentration, catalyst addition and initial dye concentration on the decolorization of MO was investigated. The results indicated that the MO decolorization rate increased with the increase of H2O2 concentration and catalyst addition, but decreased with the increase of initial MO concentration. The optimal initial pH for the decolorization was found as 3. The acute toxicity experiments illustrated that the Daphnia magna mortality declined with the progress of the oxidation. (C) 2015 Elsevier B.V. All rights reserved.