Preparation of activated carbon fromDipterocarpus alatusfruit and its application for methylene blue adsorption

Activated carbons were prepared from three parts ofDipterocarpus alatusfruit (wing, endocarp and pericarp), an abundant and renewable waste in Southeast Asia, by chemical activation using ZnCl2, FeCl3, H(3)PO(4)and KOH and physical activation using CO(2)and steam. This study indicated that activated carbon prepared fromDipterocarpus alatusfruit could be employed as a promising adsorbent for the removal of methylene blue from aqueous solution. ZnCl(2)activation led to an activated carbon with a surface area of 843 m(2)g(-1)and was able to remove methylene blue from aqueous solution. Adsorption studies were performed and analysed using Langmuir and Freundlich isotherm equations. Adsorption data demonstrated an excellent fit with the Langmuir isotherm model, with the maximum adsorption capacity of 269.3 mg g(-1)at equilibrium. Pseudo-first order and pseudo-second order kinetic models were used in this study to describe the adsorption mechanism. The results show that methylene blue adsorption is pseudo-second order, indicating that liquid film diffusion, intra-particle diffusion and surface adsorption coexisted during methylene blue adsorption on the activated carbon. The activated carbon prepared fromDipterocarpus alatusfruit is a low cost and effective adsorbent with a fast rate for the removal of methylene blue from aqueous solutions when compared with a number of activated carbons studied in the literature.