KINETICS OF PHOTODECOLORIZATION OF METHYL-ORANGE USING TITANIUM-DIOXIDE AS CATALYST

The kinetics of decolorization of methyl orange (MO) photocatalyzed by titanium dioxide in a slurry reactor was both theoretically and experimentally studied. Factors affecting the decolorization rate were obtained. A reaction mechanism was proposed. The activation energy of the decolorization of methyl orange is 18 kJ/mol. The initial decolorization rate equation is R(i) = 0.089[TiO2]0.5P0.25 X [4.1P(O2)/(1 + 4.1P(O2))] [0.18[MO]b/(1 + 0.18[MO]b + 0.17[MO]b)], where P, [MO]b, and P(O2) are the intensity of light, the concentration of methyl orange in the bulk solution, and the partial pressure of oxygen, respectively. The theoretical analysis results correlate the experimental results well.