Adsorbents were prepared in two steps using CS bead preparations followed by functionalization. First, the CS hydrogel beads were prepared using a dropping method. The chitosan solution was prepared by dissolving an aliquot of chitosan flakes (2 g) in 100 mL of a 1% (v/v) acetic acid solution. To prepare a uniform solution, the 2% CS solution was stirred continuously on a magnetic stirrer (Favorite, Malaysia) for 5 h at room temperature (30 ± 2 °C). Thereafter, the CS hydrogel beads were obtained by the dropwise addition of the resulting solution into a precipitation bath containing a 2 M NaOH solution. The mixture was then continuously stirred slowly overnight to neutralize the acetic acid. The beads were then extensively washed with distilled water to remove the NaOH until neutralization and then stored in distilled water for future use.