The Adsorption of methylene blue dye on activated carbon prepared from molasses by using chemical and microwave ctivation

Abstract

This research aims to produce activated carbon from molasses via a chemical activation process with potassium hydroxide (KOH) and a microwave heating process, which consumes less energy and provides more rapid and uniform heat distribution than a conventional heating. The obtained activated carbon was then characterized with BET, SEM and FTIR. It exhibited a large specific surface area of 1,631 m2/g, and a total pore volume of 1.124 cm3/g consisting of mesopore and micropore. In addition, the active functional groups were also found on the surface of the activated carbon. Thus, it was brought for the adsorption test with methylene blue. It was found that the adsorption capacity of the activated carbon increased with time and reached the equilibrium within 8 hours. The adsorption data of the activated carbon were corresponded to Langmuir isotherm with the highest adsorption capacity of 370.37 mg/g. The adsorption kinetic of the activated carbon exhibited pseudo-second order reaction suggesting to the chemisorption phenomenon. From the thermodynamic study, it revealed that the adsorption process were endothermic and spontaneous reactions.