Coconut husk derived activated carbon via microwave induced activation: Effects of activation agents, preparation parameters and adsorption performance

Preparation of activated carbon has been attempted from coconut husk (CHAC) via microwave assisted chemical activation. The operational parameters including the effects of activation agents, chemical impregnation ratio (0.25–2.00), microwave power (90–800 W) and irradiation time (4–8 min) on the carbon yield and adsorption capability were investigated. CHAC was examined by pore structural analysis, Scanning Electron Microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption isotherm, elemental analysis, and zeta potential measurement, while the adsorptive property was quantified using methylene blue (MB) as dye model compound. The best conditions (KOH as activating agent, IR of 1.25, microwave power of 600 W and radiation time of 6 min) resulted in CHAC with a monolayer adsorption capacity of 418.15 mg/g for MB and carbon yield of 80.75%. The BET surface area, Langmuir surface area and total pore volume were identified to be 1356.25 m2/g, 2040.01 m2/g and 0.780 m3/g, respectively. Equilibrium data were favorably described by the Langmuir isotherm, while the adsorption kinetic was satisfactory fitted to the pseudo-second-order model.

Activation agent: KOH; impregnation ratio: 1.25; microwave power: 600 W; and radiation time: 6 min.Figure optionsDownload as PowerPoint slideHighlights
► Highlight the renewable use of coconut husk.
► Evaluate the effects of activation agents and operational parameters.
► Short activation time of 6 min and low chemical impregnation ratio of 1.25.
► High BET and Langmuir surface area of 1356.25 and 2040.01 m2/g.
► Monolayer adsorption capacity of 418.15 mg/g for MB and carbon yield of 80.75%.