Photodecomposition of direct red 81 (5-solamin) by using nano sized zinc oxide deposited on glass beads in neutral and alkaline pH and various atmospheres

This research describes photo degradation of direct red 81(5-solamin) in the presence of zinc oxide nano-sized catalyst supported on granule glass under UV light irradiation. The effects of some parameters such as various pH and different atmosphere on photo degradation efficiency were studied. After various experiments it was revealed that among various atmospheres, at neutural medium, oxygen and air and at alkaline medium nitrogen and oxygen were found as the best atmosphere for photo-degradation. The rate constants of 0.007, 0.004, 0.001 and 0.001 mg/L.min were evaluated for air, oxygen, nitrogen, and argon atmospheres respectively at neutral while the rate constant values of 0.005, 0.004, 0.001 and 0.001 mg/L.min were found for alkaline conditions in the presence of nitrogen, oxygen, air, and argon atmospheres respectively.