Chitosan-based advanced materials for wastewater treatment: a comparative study on adsorption efficiency and molecular interactions

The performance of two chitosan-based composite materials (CS-ECH and CS-GA), incorporating spinel ferrites nanoparticles, was evaluated for the adsorption of the anionic dye Orange II. The magnetic materials were characterized in terms of their morphological, structural, and magnetic properties, showing the adsorption efficiencies of 96.31% for CS-ECH (pH 5.2, sorbent dose 1.60 g/L) and 98.01% for CS-GA (pH 2.51, sorbent dose 3.88 g/L). Molecular docking simulations indicated Van der Waals energies of -20 kcal/mol and Coulomb energies of -130 kcal/mol for CS-GA, compared to -10 kcal/mol and -85 kcal/mol for CS-ECH, suggesting stronger interactions and a higher adsorption capacity for CS-GA. However, CS-ECH offers the advantage of efficient magnetic recovery, allowing reuse for at least five cycles without significant loss of efficiency.