Activated Carbon from Meranti Wood Sawdust Waste Prepared by Microwave Heating for Dye Removal

Abstract

Ionic dyes pose a great difficulty to be eliminated in wastewater by conventional methods due to their highly soluble properties. This study aims to synthesis meranti wood-based activated carbon (MWAC) for methylene blue (MB) dye removal from aqueous solution. The MWAC was produced via physiochemical activation method which involves potassium hydroxide (KOH) treatment, carbon dioxide (CO2) gasification and microwave heating. Optimum preparation conditions of MWAC were found at microwave radiation power, radiation time and impregnation ratio (IR) of 365 W, 4.63 min and 0.85, respectively, which resulted in 88.0% of MB removal and 31.17% of MWAC yield. This sample shows high Bruneaur–Emmet–Teller (BET) surface area and total pore volume of 1257.22 m2/g and 0.587 cm3/g, respectively. The MB adsorption equilibrium followed Langmuir isotherm with monolayer adsorption capacity of 344.83 mg/g. MB adsorption onto MWAC followed pseudo-second-order kinetic model while thermodynamic studies confirmed the exothermic in nature. Mechanism studies revealed that the adsorption process was controlled by film diffusion mechanism.