Butt, Alicia LevanaMpinga, John KabanguTichapondwa, Shepherd Masimba2022-07-202022-07-202021-11-29Butt, A.L.; Mpinga, J.K.; Tichapondwa, S.M. Photo-Fenton Oxidation of Methyl Orange Dye Using South African Ilmenite Sands as a Catalyst. Catalysts 2021, 11, 1452. https://DOI.org/10.3390/catal11121452.2073-4344 (online)10.3390/catal11121452https://repository.up.ac.za/handle/2263/86317Figure S1: SEM-EDS Micrographs of three different sites (a, b and c) of the catalyst sample using EDS to determine the elemental composition.In this study, the viability of South African ilmenite sands as a catalyst in the photo-Fentonlike degradation of methyl orange (MO) dye was investigated. The mineralogy and other properties of the material were characterized. Complete decolorization occurred under acidic conditions (pH < 4) in the presence of ilmenite and H2O2. Light irradiation accelerated the rate of reaction. Parameter optimization revealed that a pH of 2.5, UVB irradiation, 2 g/L catalyst loading, and a hydrogen peroxide concentration of 1.0 mM were required. Under these conditions, complete decolorization was observed after 45 min. Degradation kinetics were best described by the pseudofirst order (PFO) model. Rate constants of 0.095 and 0.034 min1 were obtained for 5 and 20 mg/L MO concentrations, respectively. A 37% total organic carbon removal was observed after 60 min. This suggests a stepwise MO degradation pathway with intermediate formation rather than complete mineralization. Although iron leaching was detected, the mineralogy of the catalyst recovered after the reaction was similar to the fresh catalyst.en© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Fenton’s reactionWastewaterDegradationTextile dyeSouth African ilmenite sandsMethyl orange dyeAdvanced oxidation processes (AOPs)Article