Chitosan supported on porous glass beads as a new green adsorbent for heavy metal recovery

This paper presents a new green adsorbent-chitosan supported on porous glass beads and its heavy metal adsorption properties. The adsorbent was characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermo Gravimetric Analyzer (TGA), and BET analysis. The adsorption properties and capacities to several kinds of heavy metal ions were determined, different from pure chitosan pellets, the as-prepared adsorbent showed fast kinetic, high adsorption capacities, and good regeneration performance. When the content of chitosan was lower than 12.07 wt.%, more than 90% of lead ions were adsorbed within 90 min with an initial concentration of 100 mg/L at 303 K. Chitosan supported on porous glass beads showed high adsorption abilities for heavy metal ions with capacities achieving up to 2.47, 7.27, 8.84, 5.15, and 4.29 m mol/g for Ni2+, Cu2+, Pb2+, Ag+, and Cd2+, respectively. This adsorbent could be regenerated easily by dilute ammonia solution, showing 100% recovery after five cycles. The prepared porous glass beads supported with chitosan exhibit high mechanical strength, large specific surface area, and no obvious swelling in water, offering possibilities for future practical use.