Microwave-assisted production and characterization of activated carbon from mahogany fruit husk and its application on methylene blue adsorption

The use of activated carbon from agricultural wastes has gained much research interest due to its great economic and environmental value. In this study, microwave energy was investigated as an alternative heat treatment in the activation of carbon from mahogany fruit husk toward methylene blue (MB) removal. Interactions between Mahogany fruit husk activated carbon (MFHAC) preparation variables were determined through optimization using response surface method (RSM) with central composite design (CCD). Analysis of the surface characteristics of the microwaved MFHAC revealed the presence of acidic functional groups. It also had well developed crystalline carbon structure with ordered pores. Adsorption of MB on microwaved MFHAC fitted the Langmuir isotherm and followed the pseudo-second order kinetic model. Adsorption at pH 11.89 increased the MB removal efficiency of the microwaved MFHAC to its maximum while MB concentration showed the highest positive effect on MB removal at around 52.82 ppm. The process via microwave irradiation provides significantly lesser heating time and lower energy consumption as compared to conventional heating method to produce activated carbon of comparable quality. Hence, microwave-assisted activation of mahogany fruit husk can be used for the efficient removal of methylene blue in wastewater