| Popis: |
Laboratory research in the photo-catalytic degradation of dyes in aqueous slurry of TiO2 under UV light radiation has been shown to be potentially applicable in the treatment of wastewater effluents from textile plants. Therefore, reliable kinetic data that are free from mass transfer limitations are required for the design and scale-up of the photo reactor. In this study, batch experiments were designed to measure the mass transfer coefficient, adsorption equilibrium constant and chemical reaction rate constant for the dye reactive orange 16. The mass transfer coefficient was determined for mixing speeds of 240 - 660 rpm with corresponding values of 3.0x10-5 to 2.8 x10-4 1/s, respectively. The mass transfer coefficient became constant for mixing speeds at or greater than 600 rpm. The adsorption equilibrium constant was determined using the Langmuir Isotherm model, and a value of 1.09x10-4 l/mg was determined. The integrated form of the Langmuir-Hinshelwood model was used to describe the photo-oxidation kinetics. The rate constant was determined at different UV light intensities of 8.8 - 26.4 mW/cm2 and the corresponding values were 146.38 - 381.20 mg/l.min, respectively. The relation between the rate constant and UV light intensity can be described by the formula: 1/kr=a/I^0.5 +b . |
