OICC Press Iranian Journal of Catalysis 2345-4865 15 1 2025 01 27 Optimization of Photocatalytic Degradation of Safranin O under UV and Visible Light using ZnFe2O4 Coated Graphited Sand in Batch and Continuous Systems 1 13 10.57647/j.ijc.2025.1501.10 EN Hussein A. Khalaf Chemistry Department, Faculty of Science, Damanhour University, Damanhour, Egypt Mariam Essam Chemistry Department, Faculty of Science, Damanhour University, Damanhour, Egypt Emad A, Matter Chemistry Department, Faculty of Science, Damanhour University, Damanhour, Egypt https://orcid.org/0009-0007-7209-5247 Gada Esmail Abd Elgawad Chemistry Department, Faculty of Science, Damanhour University, Damanhour, Egypt https://orcid.org/0009-0000-6221-5013 Journal Article 2025 01 27 Zinc ferrite (ZF) coated graphited sand (GS) was synthesized using the coprecipitation method.  The produced zinc ferrite-coated graphitic sand (ZFGS) has been characterized by X-ray diffraction (XRD), Scan Electron Microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDS), Brunauer-Emmett-Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR), Diffuse Reflectance Spectroscopy (DRS), and zeta potential measurements. The ZFGS catalyst was employed for the photodegradation of safranin O under both UV and visible light. Photodegradation experiments were conducted using batch and fixed-bed column methods under varying conditions. A fractional factorial design was utilized to assess the effects of pH, dye concentration, irradiation time, and catalyst dosage on degradation efficiency, with interactions analyzed through Analysis of Variance (ANOVA). The ANOVA results indicated that pH, catalyst dosage, and irradiation time significantly influenced degradation, while dye concentration had minimal impact. Optimization showed a strong agreement between experimental and predicted degradation efficiencies, supported by a high correlation coefficient and significant F-ratio, validating the model. Maximum degradation efficiencies of 98.8% under UV light and 90.4% under visible light were achieved at optimal conditions: 50 mg/L dye concentration, 0.3 g catalyst dosage, pH 9, and 45 minutes of irradiation. Breakthrough curve analysis highlighted strong interactions among these variables. Research Highlights: A new composite material, ZnFe₂O₄/graphited sand, was synthesized. Providing a unique catalyst for photocatalytic degradation applications under both UV and visible light. ZnFe₂O₄/GS was employed for the photodegradation of safranin O dye under both UV and visible light. A fractional factorial design and ANOVA were applied to analyze the effects of key variables. The photodegradation process of SO dye was studied using batch and fixed bed column study.