title: Photocatalytic transformation of dyes and by-products in the presence of hydrogen peroxide.
abstract: The efficiency of the photocatalytic degradation of dyes and dyeing industry pollutants on immobilized photocatalysts can be improved by addition of hydrogen peroxide, due to its photocatalytic decomposition on TiO2. Experiments were carried out with two azodyes, Acid Orange-7 (AO-7) and Tartrazine (Tart), with 3-nitrobenzenesulfonic add (3-NBSA) which is a chemical intermediate in the dye industry and with real industrial wastewaters, using a thin-film fixed bed reactor. The effect of hydrogen peroxide is only significant for concentrations higher than 5 x 10(-3) M (170 mg l(-1)).
mesh_terms: D019149:Bioreactors; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007220:Industrial Waste; D016877:Oxidants / Q000737:chemistry*; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D016877:Oxidants; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium