Activated Carbons from KOH-activation of Salacca Peels as Low Cost Potential Adsorbents for Dye Removal

Abstract

Salacca peel was used to prepare activated carbon (AC) by chemical activation with potassium hydroxide (KOH). The activated carbon with the largest surface area and most developed porosity was then used in the batch adsorption experiments of methylene blue (MB). Activated carbons with a surface area of around 1939 m2/g were obtained. The adsorption equilibrium and kinetics of MB dyes from aquaeous solution on AC were also investigated. Adsorption isotherms of MB were correlated with the Langmuir, Freundich, Dubinin Radushkevich and Tempkin equations, and the heat of adsorption was determined. It was revealed that the Langmuir adsorption equation was more appropriate to represent the adsorption procedure of MB dyes compared to the other equations. Two simplified kinetic models including pseudo first- order and -second-order equations were used to evaluate the adsorption processes. The results indicated that the adsorption of MB dyes could be described properly by a pseudo-second-order equation. The kinetic parameters of this model were calculated and discussed.