New insights into the effective removal of Basic Red 46 onto activated carbon produced from pomegranate peels

This study sought to reckon the efficacy of activated carbon from pomegranate peels (ACPP) in removing Basic Red 46 (BR46). The yielded sample was then characterized by XRD, FTIR, SEM/EDS, BET/BJH, pH_pzc, and Boehm titration, showing an amorphous and mesoporous structure with a specific surface area of 102.068 m² g⁻¹, along with the sight of varied functional groups on the surface. The highest adsorption capacity of 1021.11 mg g⁻¹ was attained at a solution pH of 6, an adsorbent dosage of 0.8 g L⁻¹, and a stirring speed of 500 rpm at 25 °C for 60 min. The equilibrium investigation revealed that the Freundlich model is the most suitable, while the kinetic study implied that the pseudo-second-order model accurately characterizes the process (R² ≥ 0.999). In addition, the thermodynamic study disclosed that the adsorption process was spontaneous (ΔG° < 0) and endothermic (ΔH° = 95.41 kJ mol⁻¹), with a growth in the randomness at the solid–liquid interface (ΔS° > 0). Besides, the adsorption capacity is reduced to 932 mg g⁻¹ after the 4th cycle, meaning the material may be recycled four times without losing its effectiveness. In closing, ACPP exhibited good surface properties and high effectiveness in removing BR46, demonstrating its promise of being employed in wastewater treatment.