title: Fenton degradation of sulfanilamide in the presence of Al,Fe-pillared clay: Catalytic behavior and identification of the intermediates.
abstract: Liquid phase catalytic degradation of sulfanilamide with H2O2 was carried out in the presence of Fe,Al/M-pillared clay (Fe,Al/M-MM, M=Na(+), Ca(2+) and Ba(2+)) as heterogeneous Fenton type catalyst. Fe,Al/M-MMs were prepared by swelling of layered aluminosilicate (90-95 wt.% montmorillonite) from a bed located in Mukhortala (Buryatia, Russia) in Na(+), Ca(2+) and Ba(2+) forms by means of the exchange of these cations with bulky Fe,Al-polyoxocations prepared at Al/Fe=10/1 and OH/(Al+Fe)=2.0, and then calcinated at 500°C. XRD method and chemical analysis demonstrated that the rate of crystalline swelling was dependent on the interlayer cations and decreased in the order: Fe,Al-/Na-MM>Fe,Al/Ca-MM>Fe,Al/Ba-MM. It was found that the catalytic properties of Fe,Al/M-MMs depended on the type of exchangeable cations. The effect of the H2O2/sulfanilamide molar ratio, the catalyst content, the reaction temperature and the reaction pH on the removal rate of sulfanilamide has been studied in the presence of Fe,Al/Na-MM. The catalyst can be applied for degradation of sulfanilamide with H2O2 for at least three successive cycles without loss of activity. HPLC analyses pointed out that the main degradation intermediate products were sulfanilic acid, benzenesulfonic acid, p-benzoquinone and aliphatic carboxylic acids.
authors.affiliation: Baikal Institute of Nature Management SB RAS, Str. Sakh'yanova 8, 670047 Ulan-Ude, Russian Federation; Buryat State University, Str. Smolina 24a, 670000 Ulan-Ude, Russian Federation. Electronic address: shan@binm.bscnet.ru.
authors.forename: Sesegma Ts
authors.initials: STs
authors.lastname: Khankhasaeva
authors.affiliation: Baikal Institute of Nature Management SB RAS, Str. Sakh'yanova 8, 670047 Ulan-Ude, Russian Federation.
authors.forename: Darima V
authors.initials: DV
authors.lastname: Dambueva
authors.affiliation: Baikal Institute of Nature Management SB RAS, Str. Sakh'yanova 8, 670047 Ulan-Ude, Russian Federation.
authors.forename: Elvira Ts
authors.initials: ETs
authors.lastname: Dashinamzhilova
authors.affiliation: Department of Applied Chemistry, Public University of Navarra, 31006 Pamplona, Spain. Electronic address: andoni@unavarra.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gil
authors.affiliation: Department of Inorganic Chemistry, University of Salamanca, Salamanca, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Vicente
authors.affiliation: Boreskov Institute of Catalysis SB RAS, Prospekt Akad. Lavrentieva 5, 630090 Novosibirsk, Russian Federation; Novosibirsk State University, St. Pirogova 2, 630090 Novosibirsk, Russian Federation; Novosibirsk State Technical University, Prospekt K. Marksa 20, 630092 Novosibirsk, Russian Federation. Electronic address: timofeeva@catalysis.ru.
authors.forename: Maria N
authors.initials: MN
authors.lastname: Timofeeva
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D002384:Catalysis; D000077215:Clay; D006861:Hydrogen Peroxide / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D000077145:Sulfanilamide; D013424:Sulfanilamides / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D008670:Metals; D013424:Sulfanilamides; D014874:Water Pollutants, Chemical; D000077145:Sulfanilamide; D006861:Hydrogen Peroxide; D000077215:Clay
keywords: Degradation intermediates; Hydrogen peroxide; Oxidation; Pillared clays; Sulfanilamide