Photocatalytic Removal of Hexavalet Chromium from Aqueous Solution Using Zinc Oxide Nanoparticle Stabilized On Zeolite

Backgrounds & objectives: Heavy metals, such as chromium, are the most common pollutants usually found in high concentrations in industrial wastewater and cause damages to aquatic environments and endanger the health of living organisms, especially human. Therefore, the purpose of this research was to investigate the photocatalytic removal of hexavalent chromium from aqueous solution using UV/ZnO-Zeo process in a batch system. Methods: This research was an experimental and applied study conducted in a laboratory scale. At first, the design and construction of the reactor were carried out and then the zinc oxide nanoparticles were synthesized by hydrothermal method and stabilized on zeolite. Then, by changing the content of Zno-Zeolite nanoparticles and keeping the other effective factors constant, the optimum amount of Zno-Zeo was obtained in 1.5 g/l. Subsequently, the effect of pH, contact time and initial concentration of hexavalent chromium were studied at the constant amount of ZnO-Zeo (1.5g/L). Results: The result showed that photocatalytic removal efficiency increased with elevation in reaction time and ZnO-Zeo dosage. In addition, it was found that with decreasing the pH from 11 to 3, the efficiency of hexavalent chromium removal increased from 36% to 88 %. Conclusion: The results showed that UV/ZnO-Zeo can be used as an effective and effient method for removal of hexavalent chromium from aqueous solutions.