A cost effective method for regeneration of durian shell and jackfruit peel activated carbons by microwave irradiation

An investigation was performed for the regeneration of durian shell and jackfruit peel activated carbons loaded with methylene blue dye (MB). The exhausted carbons were treated in a modified conventional microwave oven operated at 2.45 GHz and irradiation time of 3 and 4 min. The efficacy of the regeneration study was analyzed by determining the carbon yield and amount of MB adsorbed in successive adsorption–regeneration cycles. The virgin properties of the original and regenerated activated carbons were characterized by pore structural analysis, nitrogen adsorption isotherm, surface acidity/basicity and zeta potential measurement. Equilibrium data were simulated using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models.The adsorption uptake and carbon yield of the regenerated activated carbons could maintain at 181.43–207.57 mg/g and 80.51–81.63%, even after five adsorption–regeneration cycles. Microwave heating preserved the porous structure of the exhausted activated carbons efficiently to restore the original active sites and adsorption capacity.

► Regeneration of durian shell and jackfruit peel activated carbons by microwave heating.
► Evaluate the effects of microwave irradiation to the physical and chemical changes.
► Short regeneration time of 3–4 min.
► Outline the heating phenomenon and propose mechanism.
► Good preservation of porosity structure and adsorptive properties.