Mesoporous-activated carbon prepared from chitosan flakes via single-step sodium hydroxide activation for the adsorption of methylene blue

In this work, mesoporous-activated carbon (CSAC) was prepared from chitosan flakes (CS) via single-step sodium hydroxide activation for the adsorption of methylene blue (MB). CSAC was prepared using different impregnation ratios of NaOH: CS (1:1, 2:1,3:1, and 4:1) at 800 degrees C for 90 min. The adsorption performance of CSAC was evaluated for MB at different adsorption variables, such MB initial concentrations (25-400 mg/L), solution pH (3-11), and temperature (30-50 degrees C). The adsorption isotherm data of CSAC-MB were well fitted to Langmuir model with a maximum adsorption capacity 143.53 mg/g at 50 degrees C. Best representation of kinetic data was obtained by the pseudo-second order model. CSAC exhibited excellent adsorption uptake for MB and can potentially be used for other cationic dyes. (C) 2017 Elsevier B.V. All rights reserved.