Visible light induced heterogeneous advanced oxidation process to degrade pararosanilin dye in aqueous suspension of ZnO

830-835The photocatalytic degradation of pararosanilin dye has been investigated under visible light in the presence of aqueous suspension of ZnO under different conditions. The reaction has been studied by monitoring the change in substrate concentration employing visible spectrophotometric analysis as a function of time. The absorbance of dye under investigation is found to decrease in the presence of ZnO and visible irradiation. The degradation of selected dye has been studied under different process variables such as reaction pH, catalyst loading, substrate concentration, light intensity and presence of electron acceptors, and hydroxyl radical scavengers. The rate degradation was strongly influenced by all the above-mentioned parameters. The estimated COD and CO₂ values of treated dye sample indicate complete degradation of dye. A slight decrease in pH and gradual increase in conductivity has also been observed during the degradation process. ZnO has been found to be potentially efficient in solar irradiation for the degradation of dye. Kinetic analysis indicates the complex nature of heterogeneous photocatalytic process