The degradation of azo dyes and the determine kinetic parameters in water during by photo-catalytic oxidation process

In this study, the first aim of this study was to determine the photo-catalytic oxidation for three composed of 3, 4, and 5 aromatic rings of MG, RB5 ve RR198 in water until discolorization by UV/TiO2 and UV/ZnO. the optimum decolorization pH values by photo-catalytic processes were investiagted; this value for MG, rutile and ZnO, for RB5, anatase, for RR198, anatase and rutile, were acidic (pH3). The notr pH was observed for MG with anatase and for RB5 with rutile. The basic pH (pH10) was observed for RB5 and RR198 with ZnO. Photocatalytic degradation kinetics of MG, RB5 and RR198 successfully fitted to Langmuir?Hinshelwood (L?H) kinetics model. The values of second order degradation rate constants (k?) for anatase system were determined as 6.79.10-3 min-1 , 1,75.10-3min-1 , 1,20.10-3min-1, respectively.