Initial Observation on Methyl Orange Decolorization Using CaO/Fe₂O₃ Catalyst

Abstract

Methylene orange (MO) is a toxic fabric dye to the environment and health. Therefore, some actions are needed to overcome this problem. The advanced oxidation process (AOPs), especially Fenton by hydrogen peroxide (H2O2) and CaO/Fe2O3, is a powerful method to be implemented. In this experiment, the CaO/Fe2O3 was prepared by impregnation using CaO derived from chicken eggshell waste and Fe(NO3)3⸳9H2O powder with calcination temperature variations of 600, 700, and 800°C. Then, the characterization of materials was identified by Fourier Transform Infrared (FTIR), X-ray diffractometer (XRD), scanning electron microscope (SEM), and electron dispersive spectroscopy (EDS), followed by a visual observation decolorization test. Using FTIR and XRD, CaO has been successfully obtained through the calcination process. Fe2O3 was also detected, indicating impregnated into CaO support. The particle size ranges from 37–48 mm, appearing irregular in shape. Finally, the fastest decolorization of MO resulted in CaO/Fe2O3 with 800°C of calcination temperature. These results indicated that CaO/Fe2O3 nanocomposite catalyst is the potential to reduce liquid pollutants and utilize a waste resource.