Microwave-Assisted Synthesis of Polyethyleneimine Grafted Chitosan Beads for the Adsorption of Acid Red 27

In this study, chitosan-polyethyleneimine beads were synthesized via graft copolymerization under microwave irradiation for the adsorption of Acid Red 27 (AR27). The integration of polyethyleneimine affords grafting of amino functional groups onto the chitosan backbone, while crosslinking with glutaraldehyde has significantly improved the mechanical and chemical properties of the resulting grafted and crosslinked chitosan beads (CS-PEI-GLA). The beads were characterized by the scanning electron microscopy, pore structure analysis and Fourier transform infrared spectroscopy. The adsorption experiments were conducted in a batch system and optimized with respect to different adsorbent dosages, pH, initial dye concentrations and contact time. The equilibrium data were well described by the pseudo-second-order kinetic model and the Langmuir isotherm model with the maximum adsorption capacity ( q m ) for AR27 of 48.3 mg g −1 at 27 °C. CS-PEI-GLA was successfully synthesized in this study by using a simple, green and cost-effective technique with promising prospects to enable future scale-up.