PHOTODEGRADATION OF ORGANIC POLLUTANT IN WATER USING ZINC OXIDE (ZnO) AND TITANIUM DIOXIDE (TiO2)

Abstract

ABSTRACT This research investigated the Photodegradation of organic pollutant in water using zinc oxide (zno) and titanium dioxide (tio2), a sustainable approach to water purification. The aim of the research is to evaluate the effectiveness of green catalysts in the photodegradation of organic pollutants in water as a sustainable approach to water and the specific objectives are; To identify common organic pollutants in collected water samples, to evaluate the photodegradation efficiency of the green catalysts under visible light and to assess the environmental compatibility and reusability of the catalysts. The materials used in this study includes various chemical reagents and green catalytic substances intended for the photodegradation process. All reagents were analytically graded and used without further purification. Distilled water was used throughout the experiments for the preparation of solutions and for rinsing purposes. A stock solution of methylene blue, was prepared by dissolving 10 mg/L quantity of methylene blue in distilled water to obtain a concentration of 10 mg/L. This solution was stored in an amber bottle and kept away from direct sunlight to prevent premature degradation. The results indicate a progressive decrease in absorbance with increasing irradiation time, reflecting the degradation of methylene blue dye. The concentration values followed the same trend, declining steadily from 1.82 × 10⁻⁵ mol L⁻¹ at 0 min to 2.73 × 10⁻⁶ mol L⁻¹ at 50 min. The degradation efficiency reached 85% after 50 minutes, which demonstrates that the irradiation process was effective in breaking down methylene blue molecules. The study recommended that future research should focus on optimizing variables such as catalyst concentration, irradiation intensity, and pH for maximum degradation efficiency.