title: Role of active oxidative species on TiO2 photocatalysis of tetracycline and optimization of photocatalytic degradation conditions.
abstract: The optimum operating conditions for TiO2 photocatalytic degradation of tetracycline antibiotic (TC) in aqueous solution and the role of active oxidative species (AOS) from UV/TiO2 in its degradation were investigated. Response surface methodology (RSM) and central composite design (CCD) were adopted to optimize three parameters: TiO2 concentration, initial pH and UV irradiation time. Radical scavengers were added to reaction solution to assess the photocatalytic reaction mechanism of TC. The results showed that 93.1% degradation efficiency was obtained under optimum conditions established during experimentation (TiO2 concentration = 2.09 g l(-1), pH = 5.56 and t = 20.95 min). These results agree with the prediction made by the proposed model. Photocatalytic degradation of TC followed a pseudo first-order reaction rate. Photogenerated holes (h+(VB)) with minor participation from superoxide anions (O2*), were responsible for TC oxidation on TiO2, while hydroxyl radicals (*OH) played a negligible role in titania-TC oxidation.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Luo
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Chuanlin
authors.initials: C
authors.lastname: Wei
authors.forename: Huixin
authors.initials: H
authors.lastname: Li
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
mesh_terms: D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010782:Photolysis; D017382:Reactive Oxygen Species / Q000737:chemistry*; D013752:Tetracycline / Q000737:chemistry* / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium; D013752:Tetracycline