Methylene blue adsorption from aqueous solution using activated carbon of spathodea campanulata

Abstract

This study aimed to determine the effectiveness of Spathodea Campanulata derived activated carbon in removing methylene blue (MB) from wastewater. The activated carbon was prepared through chemical impregnation with H3PO4 and thermal activation at 500 °C for 2 h. The adsorption experiments were optimized using 24 full factorial designs, considering pH, contact time, initial MB concentration, and adsorbent dosage as parameters. The characterization of the activated carbon revealed favorable properties, including multiple surface functional groups, a maximum specific surface area of 1054 m2/g, and a highly porous surface morphology. The optimized conditions achieved a maximum removal efficiency of 99.95%, with pH 9, a contact time of 120 min, a dye concentration of 90 mg/L, and an adsorbent dosage of 0.2 g/100 mL being the most effective parameters. The Freundlich isotherm model provided the best fit to the experimental data, indicating a heterogeneous and multilayer adsorbent surface. The kinetics study indicated that chemisorption was the primary mechanism. In conclusion, the study indicated that Spathodea Campanulata based activated carbon could serve as a cost-effective adsorbent for removing MB from aqueous solutions

Keywords

• Activated carbon
• Adsorption
• Methylene blue
• Spathodea campanulata
• Wastewater treatment