Photocatalytic degradation of methylene blue by waste ZnO catalyst

Abstract

The purpose of this study, the usability of the ZnO content of waste which produces from metal waste recycling industries as a catalyst was investigated for the removal of methylene blue by the photocatalytic oxidation process. For this purpose, a zinc content powder which is held with the cyclones during recycling of copper and zinc containing waste is used as a catalyst Properties of waste ZnO were demonstrated by the SEM-EDX and FTIR analysis. ZnO/UV and ZnO/H2O2/UV processes have been investigated in the photocatalytic oxidation experiments. According to obtained results, 95% of methylene blue removal efficiency was obtained for ZnO (2.5 g/L)/UV and 10 mg/L initial methylene blue. At a high initial methylene blue concentration (50 mg/L), approximately 99% of methylene blue removal can be obtained with the addition of 7.5 mM H2O2. According to toxicity (Daphnia Magna) experiment results, immobilization of Daphnia Magna was observed at 100% at initial methylene blue concentration while it was dropped off 5% at treated samples As a result, the zinc containing waste generated in the industries can be used for dye removal with photocatalytic oxidation process. In this way, the catalyst cost and, consequently operation cost can be reduced in the photocatalytic oxidation process, and waste recycling and/or minimization in the waste recycling industries will be provided.