Utilization of agro-waste derived activated carbon for wastewater treatment: Adsorptive removal of brilliant blue dye

Adsorption remains one of the most effective and widely applied methods for removing pollutants from water and wastewater. However, the high cost of conventional industrial adsorbents limits their application, particularly in developing countries. To address this challenge, the present study focuses on creating a low-cost, eco-friendly biosorbent derived from pomegranate peel waste. The biomass was converted into activated carbon (PPAC) through a microwave-induced chemical activation method using phosphoric acid (H₃PO₄) as the activating agent. The preparation involved impregnating dried and pulverized pomegranate peels with concentrated H₃PO₄, followed by microwave irradiation to induce carbonization and activation. The resultant activated carbon was thoroughly washed to neutral pH and dried before use. The surface morphology and physicochemical properties of the PPAC were characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). These analyses confirmed the presence of abundant functional groups (e.g., –OH, –COOH, and –PO₄), an amorphous carbon structure, and a highly porous surface, all of which contribute to enhanced adsorption capacity. The adsorptive performance of PPAC was evaluated in batch experiments for removing Brilliant Blue (BB), a synthetic cationic dye, from aqueous solution. Several operational parameters were optimized, including pH, initial dye concentration, contact time, and temperature. The results revealed maximum dye removal efficiency (89.36%) at pH 6. Furthermore, under optimized conditions—pH 6, adsorbent dose of 0.05 g/100 mL, BB concentration of 60 mg/L, and contact time of 60 minutes—PPAC demonstrated an impressive removal efficiency of up to 89 %.These findings confirm the potential of pomegranate peel-derived activated carbon as a sustainable and cost-effective biosorbent for treating dye-contaminated wastewater, particularly in resource-limited settings.