title: Photochemical degradation of the hazardous dye Safranin-T using TiO2 catalyst.
abstract: Aqueous solutions of Safranin-T, a hazardous textile dye, are photodegraded under ultraviolet light using TiO2 as catalyst. The process has been carried out at different pHs, amounts of catalyst, concentrations of the dye, and effects of the electron acceptor H2O2. It is found that under the influence of TiO2 as catalyst the colored solution of the dye Safranin-T becomes colorless and the process follows first-order reaction kinetics. The optimum conditions for the degradation of the dye have been found as 5.0x10(-5) M dye concentration, pH 5.7, and 12 mg catalyst dose. In order to evaluate the effect of the electron acceptor, the effect of H2O2 on the degradation process is also monitored and it is found that generation of hydroxyl radicals and retardation of electron-hole recombination takes place. Measuring chemical oxygen demand also monitors the toxicity of the degraded dye solution and a significant decrease is observed, which implies that the photodegradation through TiO2 is a safer technique.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India. vinodfcy@iitr.ernet.in
authors.forename: V K
authors.initials: VK
authors.lastname: Gupta
authors.forename: Rajeev
authors.initials: R
authors.lastname: Jain
authors.forename: Alok
authors.initials: A
authors.lastname: Mittal
authors.forename: Megha
authors.initials: M
authors.lastname: Mathur
authors.forename: Shalini
authors.initials: S
authors.lastname: Sikarwar
mesh_terms: D000327:Adsorption; D002384:Catalysis; D015386:Hazardous Substances; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015394:Molecular Structure; D010619:Phenazines / Q000737:chemistry* / Q000528:radiation effects; D010777:Photochemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D015386:Hazardous Substances; D010619:Phenazines; C009495:titanium dioxide; D014025:Titanium; C009195:safranine T