Batch Removal of Lead Ions from Aquatic Solutions by Polyethyleneglycol-Methacrylate Gel Beads Carrying Cibacron Blue F3GA

Abstract

Polyethyleneglycolmethacrylate [PEG-MA] gel beads (100-120 µm in diameter) carrying Cibacron Blue F3GA (42.6 µmol g⁻¹ polymer) were prepared for the removal of Pb(II) ions from aqueous solutions containing different amount of these ions (10-600 mg l⁻¹) and at different pH values (2.0-6.4). Pb(II) adsorption capacity increases with the time during the first 20 min and then levels off toward the equilibrium adsorption capacity. Adsorption of Pb(II) ions on the unmodified PEG-MA gel beads was zero. Cibacron Blue F3GA-immobilisation significantly increased the Pb(II) adsorption (23.3 mg g⁻¹ polymer). Langmuir adsorption model was found to be applicaple in interpreting lead adsorption by Cibacron Blue F3GA-immobilised PEG-MA gel beads. The adsorption of Pb(II) ions increased with increasing pH and reached a plateau value at around pH 5.0. The optimal pH range for Pb(II) adsorption was shown to be from 5.0 to 6.0. PEG-MA gel beads can be regenerated by washing with a solution of nitric acid (0.1 M). The maximum regeneration value was as high as 98%. These PEG-MA gel beads are suitable for repeated use for more than three adsorption-desorption cycles without considerable loss of adsorption capacity.