Equilibrium, kinetic, and thermodynamic studies of new materials based on xanthan gum and cobalt ferrite for dye adsorption.

The present work is focused on developing new eco‐friendly materials based on xanthan gum (XG) and cobalt ferrite (CF) nanoparticles with adsorptive properties. CF powder was prepared by the co‐precipitation method. Esterification of XG was performed in order to improve its hydrophobic character, resulting in xanthan acrylate (XGAC). Thin films were prepared and characterized. The influence of pH and materials' composition on their water uptake capacity was investigated. Batch adsorption experiments were performed to evaluate the dye adsorption capacity of the materials. Materials comprising CF showed the highest values of dye removal percentage (up to 83%). The adsorption capacity of XGACCF for Methyl Blue (MB) was 65.56 mg g−1, while the same material retained 63.35 mg g−1 of Basic Fuchsine (BF) dye solution. Equilibrium adsorption data were well fitted to two (Langmuir and Dubinin–Radushkevich) isotherm models. The adsorption kinetics were analyzed by the pseudo‐first‐order model, pseudo‐second‐order model, and Elovich model. A spontaneous endothermic physisorption process was recorded for MB adsorption, while BF retention was evaluated as an exothermic process. [ABSTRACT FROM AUTHOR]