KGM-based magnetic carbon aerogels matrix for the uptake of methylene blue and methyl orange

Abstract

In this study, the preparation of magnetic Fe and Mn oxides (Mag-FMBO) loaded carbon aerogels (CA) based on konjac glucomannan (KGM) and their performance for dyes adsorption were investigated. The prepared magnetic carbon aerogels (Mag-CA) materials were characterized by various methods, including BET surface area analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). What⿿s more, the Mag-CA materials were used as adsorbents to remove dyes [anionic methyl orange (MO) and cationic methylene blue (MB)] from aqueous solutions. The results showed that Mag-CA had an excellent adsorption performance towards MO and MB. The adsorption equilibrium data of both MO and MB can be well described by Langmuir model. The maximum MO and MB uptake capacity of Mag-CA reached 7.42mgg⿿1 and 9.37mgg⿿1 according to Langmuir isotherm at 303K, respectively. Thermodynamic parameters such as οG, οH and οS were estimated to understand the adsorption mechanism of MO and MB. The adsorption processes of MO and MB could be well described by the pseudo-second-order model. Moreover, Mag-CA with dyes (MO or MB) were successfully regenerated by ethanol and then easily separated from aqueous solution by applying magnetic field.