Preparation of activated carbon from edible fungi residue by microwave assisted K2CO3 activation—Application in reactive black 5 adsorption from aqueous solution

Preparation of activated carbon from the edible fungi residue (EFR) by microwave assisted K2CO3 activation was studied. The optimum preparation conditions were as follows: radiation time of 16 min, K2CO3/EFR ratio of 0.8 and microwave power of 520 W. The iodine number, the amount of methylene blue adsorption and the yield of activated carbon prepared under optimum conditions were 732.74, 172.43 mg/g and 23.0%, respectively. The activated carbon was characterized by SEM, FT-IR, N2 adsorption and pHZPC, and then they were used as adsorbent for removing reactive black 5 from aqueous solution. The highest removal efficiency of 100% could be achieved at the solution pH of 2.0, the adsorption efficiency descended with the increasing of pH and the optimum activated carbon dose was 8.75 g/L. The Langmuir isotherm well fit the adsorption process with the complete monolayer adsorption capacity of 19.6 mg/g and the equilibrium adsorption constant of 0.39 L/mg.