Removal of Titan Yellow GR from Water Using Advanced Oxidation Process (AOP) in the Presence of Suspended ZnO as a Catalyst

Abstract

UV/ZnO process was used to degrade titan yellow GR indicator which is the type of azo dyes., The effect of some parameters in the photocatalytic degradation of dye by UV/ZnO process such as: UV irradiation time, pH, the concentrations of both dye, bromate anion and ethanol were examined. First order reaction rate constant was calculated and it was found to be to 9x10-3 min-1. It was observed that the increasing in the irradiation time increased dye removal while the increasing in the concentrations of both dye in the range from 20 to 70mg/L and ethanol in the range from1 to 7mM decreased the efficiency of photoreaction. The effect of pH (from 1 to 11) on the photodegradation process of dye was studied and the maximum efficiency of the degradation was at neutral pH (pH=7). It was found that the increasing in the dye removal was regular when the concentration of bromate anion increased from 1 ـــ 3 mM. While at the higher concentrations of bromate anion (above 4 mM), the decreasing in the dye removal was also regular and the maximum dye removal was at 4mM. Also the adsorption isotherms such as: Langmuir and Freundlich were studied and were identical with the Langmuir model.