Adsorption of Malachite Green Dye onto Activated Carbon Derived from Durian Peel

The feasibility study of preparing activated carbon from durian peel by physical activation with carbon dioxide was investigated. Two pyrolysis conditions were employed and compared: nitrogen atmospheric and vacuum pyrolysis. After synthesis of activated carbon, influence of acid treatment (2 M HCl) on properties of the activated carbon was investigated. The results showed that activated carbon synthesized under vacuum pyrolysis exhibited better properties (BET surface area, pore volume) than that synthesized under nitrogen atmospheric pyrolysis. Treatment of activated carbon synthesized from both pyrolysis conditions with HCl solution increased BET surface area and pore volume. The pseudo-second-order kinetics model represented the adsorption of malachite green on HCl-treated activated carbons better than the pseudo-first-order kinetics model. The experimental adsorption equilibrium data were fitted to Langmuir and Freundlich models, with the former providing the best fit. The maximum adsorption capacities of activated carbons in this study were very high in comparison to those found in previous studies. Therefore durian peel is a promising raw material in the production of activated carbon for effective removal of malachite green, contributing to the conservation of the global environment.