The main target of this project is to investigate experimentally the removal the dyestuff from dyeing textile industrial wastewater by photosensitization process, for its reuse in the same industry or for domestic purpose and/ or irrigation. In the present work, the photocatalytic decolorization of two collected samples of real and one prepared simulated textile industrial wastewater was examined under artificial source of irradiation using titanium dioxide and zinc oxide. The effects of various operational parameters such as catalyst mass, type of catalyst, type of reactor, type of dye, dye concentration, and temperature were also investigated.
Photolysis and photocatalytic treatments were carried out over a suspension of titanium dioxide or zinc oxide under artificial irradiation. The progress of treatment stages was followed spectrophotometrically at different wavelengths. Under optimal conditions, the extent of decolorization was about 100 % after different periods of time ranging from 20 to 100 minutes. The decolorization percentages differ with the difference in type of dye used in textile industry. The results indicate clearly that titanium dioxide and zinc oxide could be used successfully in photocatalytic treatments of textile industrial wastewater. However, the order of their activity is-
ZnO > TiO2 (Anatase) > TiO2 (Rutile)
Incubations of colored industrial wastewater without light and without catalyst was also performed to demonstrate that decolorization of the dye requires the presence of both ; light and catalyst. Key words: Photocatalytic treatments, Industrial wastewater, Titanium dioxide, Zinc oxide, Decolorization efficiency.