PHOTOCATALYTIC DEGRADATION OF METHYL ORANGE IN AQUEOUS TIO2 UNDER DIFFERENT SOLAR IRRADIATION SOURCES

Abstract

The main causes of surface water and groundwater contamination are industrial discharges. Updating the field of polluted water treatment by photochemical technique has led to an important in oxidative degradation processes applying solar photochemical methods using crystal TiO2 as a catalyst. Photocatalytic oxidation of methyl orange dye under different irradiation sources (Halogen lamp 1000 W, fluorescent lamp and natural sun light ) have been studied over TiO2 catalyst. The effect of initial dye concentrations, irradiation time and  light intensity were also studied.  The results revealed that dyes under go fast degradation with the natural sun light than the halogen and fluorescent lamp sources. On other hand, fast degradation was obtained with increasing time of the Halogen and fluorescent lamps as a light source. The rate of decolorization was estimated from residual concentration spectro- photometrically. At the used experimental conditions the substrate photo-oxidation rate follows pseudo-first order kinetics.   Keywords: Photodegradation, solar irradiation, dyes, pollution, treatment, catalyst