title: Ozone-driven photocatalyzed degradation and mineralization of pesticide, Triclopyr by Au/TiO2.
abstract: Triclopyr is a widely used pesticide which is non-biodegradable and enters aquatic systems. The ozone facilitated photocatalyzed degradation and mineralization of Triclopyr using Au-loaded titania as heterogeneous catalyst is reported. The oxidative degradation activity of the hazardous pesticide was investigated at pH 7.8 under varied reaction conditions, including in presence and absence of ozone, titania alone, in presence and absence of light and with different loadings of Au on support. Photocatalysis with 2% Au/TiO2 in the presence of ozone yielded 100% degradation of Triclopyr in 2 h. The extent of degradation of pesticide and its mineralization were confirmed by GC-MS. For 10 mg/L of Triclopyr, 0.1 g/L of catalyst was found to be the optimum for mineralization. Results show that photocatalyzed ozonation with Au/TiO2 as catalyst is a very effective for its removal. No leaching of Au was observed in triplicate runs. Catalyst was fully recoverable and reusable with no loss of activity.
authors.affiliation: a School of Chemistry & Physics, University of KwaZulu-Natal , Durban , South Africa.
authors.forename: Suresh
authors.initials: S
authors.lastname: Maddila
authors.forename: Surjakanta
authors.initials: S
authors.lastname: Rana
authors.forename: Ramakanth
authors.initials: R
authors.lastname: Pagadala
authors.forename: Surya N
authors.initials: SN
authors.lastname: Maddila
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Vasam
authors.forename: Sreekantha B
authors.initials: SB
authors.lastname: Jonnalagadda
mesh_terms: D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006016:Glycolates / Q000737:chemistry*; D006046:Gold; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D010575:Pesticides / Q000737:chemistry*; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D006016:Glycolates; D010575:Pesticides; C009495:titanium dioxide; D010126:Ozone; D006046:Gold; D014025:Titanium; C032742:triclopyr
keywords: Au-TiO2; Photocatalyzed ozonation; Triclopyr; deposition-precipitation method; mineralization