title: Photo-catalytic degradation of toxic dye amaranth on TiO(2)/UV in aqueous suspensions.
abstract: The photo-catalytic degradation of an azo dye - Amaranth (AM) - has been investigated in TiO(2)/UV aqueous suspensions. The results obtained from the experiments during H(2)O(2)/TiO(2) addition show that the highest decolorization rate is provided by the combination of (UV+TiO(2)+H(2)O(2)). The decolorization efficiencies were 17%, 26%, 38% and 64% in the runs UV, UV+H(2)O(2), UV+TiO(2) and (UV+TiO(2)+H(2)O(2)) after approximately 100 min illumination periods, respectively. The observed dye degradation rates followed pseudo-first order kinetics with respect to the substrate concentration under the experimental conditions used. Different experimental conditions, such as temperature, pH and presence of electron acceptor were investigated. The temperature effect was investigated at the range of 293-313 K and it was observed that decolorization rate increased by the increase in temperature. Chemical oxygen demand and dye absorbance of the photodegraded dye solution substantially decreased. Effect of pH was also investigated and it was observed that the lower the pH the higher the degradation. In addition, an enhancement in the photodegradation rate was observed by the addition of hydrogen peroxide as an electron acceptor. The adsorption trends of Amaranth at various initial concentrations followed the Langmuir isotherm trend. This work adds to the global discussion on the role of the advanced oxidation processes in water treatment.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667, India. vinodfcy@gmail.com
authors.forename: Vinod 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: Tawfik A
authors.initials: TA
authors.lastname: Saleh
authors.forename: Arunima
authors.initials: A
authors.lastname: Nayak
authors.forename: Shilpi
authors.initials: S
authors.lastname: Agarwal
authors.forename: Shalini
authors.initials: S
authors.lastname: Sikarwar
mesh_terms: D000548:Amaranth Dye / Q000737:chemistry*; D057919:Biological Oxygen Demand Analysis; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010782:Photolysis; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D004396:Coloring Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D000548:Amaranth Dye; D014025:Titanium