Absorptive removal of methylene blue from aqueous using Moringa Oleifera extract loaded activated carbon

This study investigates the removal of methylene blue (MB) dye from aqueous solutions using activated carbon (AC) and Moringa oleifera leaf extracts loaded onto AC using hexane (MS-AC) and water (MW-AC). Key operational parameters such as dye concentration, contact time, pH, and adsorbent dosage were optimized. The MS-AC sample achieved 100% MB removal, showing superior performance compared to MW-AC and unmodified AC with a lower dose (0.05 g/L), indicating a much more efficient adsorbent. Adsorption equilibrium followed the Langmuir isotherm model, indicating monolayer adsorption, with high correlation coefficients (R² = 0.9931 for MS-AC). Freundlich and Dubinin–Radushkevich (D–R) models supported additional surface heterogeneity and confirmed that the process is endothermic and physical in nature. These findings highlight the potential of MS-AC as a low-cost, effective adsorbent for wastewater treatment applications.