title: Catalytic ozonation of Orange-G through highly interactive contributions of hematite and SBA-16 - To better understand azo-dye oxidation in nature.
abstract: Hematite-SBA-16 mixture (HS) exhibited high catalytic activity in Orange-G (OG) ozonation in water. Total OG discoloration was achieved in half the time required with hematite or SBA-16 alone, all UV-Vis bands disappeared in less than 2 min. Liquid chromatography- Mass spectrometry (LC-MS) revealed that OG ozonation triggers via both hydroxylation and desulfonation of the aromatic rings into specific intermediates. Prolonged ozonation in the presence of hematite and SBA-16 alone resulted in different distributions of common derivatives. The latter were not detected after 25 min ozonation with HS. Stochastic modeling of the evolution in time of the UV-Vis bands of OG revealed strong binary interaction between the initial pH and catalyst concentration. This was explained in terms of reciprocal contributions of: i. the catalytic properties of hematite in spite of its low porosity; ii. the high specific surface area of SBA-16 for adsorption and surface reaction notwithstanding its low intrinsic catalytic activity. The weak basicity of SBA-16 surface seems to play a key-role in adsorption. These findings are of great interest for envisaging flexible oxidative treatments, where Fe3+containing soils or mixtures of sand and rust may also act as catalyst for total mineralization of various azo-dyes, regardless to their structures.
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada; Laboratory of Science and Technology of Environment, University of Constantine-1, Algeria.
authors.forename: Safa
authors.initials: S
authors.lastname: Larouk
authors.affiliation: Department of Materials Engineering, University of Science and Technology, Oran, Algeria; Laboratory of Materials Chemistry, Oran University, BP 1524 El M'naouer, Oran, Algeria.
authors.forename: Rachida
authors.initials: R
authors.lastname: Ouargli
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada.
authors.forename: Dariush
authors.initials: D
authors.lastname: Shahidi
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada.
authors.forename: Leanne
authors.initials: L
authors.lastname: Olhund
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada.
authors.forename: Tze Chieh
authors.initials: TC
authors.lastname: Shiao
authors.affiliation: Laboratory, Mechanical Engineering Department, École de Technologie Supérieure, H3C 1K3, Canada.
authors.forename: Nacira
authors.initials: N
authors.lastname: Chergui
authors.affiliation: Laboratory of Science and Technology of Environment, University of Constantine-1, Algeria.
authors.forename: Tahar
authors.initials: T
authors.lastname: Sehili
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada.
authors.forename: René
authors.initials: R
authors.lastname: Roy
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada. Electronic address: azzouz.a@uqam.ca.
authors.forename: Abdelkrim
authors.initials: A
authors.lastname: Azzouz
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D005290:Ferric Compounds; C000600619:SBA-16; D014874:Water Pollutants, Chemical; C000499:ferric oxide; C008710:Orange G; D010126:Ozone; D012822:Silicon Dioxide
keywords: Hematite; Orange-G; Ozone; Parameter interaction; SBA-16