화학공학소재연구정보센터
Separation Science and Technology, Vol.36, No.15, 3427-3438, 2001
Selective removal of lead ions by polyethylene glycol methacrylate gel beads carrying Cibacron Blue F3GA
Polyethylene glycol methacrylate (PEG-MA) gel beads carrying Cibacron Blue F3GA (42.6 mumol/g polymer) were prepared for the removal of Pb(II), Cu(II), and Cd(II) from aqueous solutions that contained different amounts of these ions (10-100 mg/L) and at different pH values (2.0-7.0). Adsorption rates were high, and adsorption equilibria were reached within 20 minutes. Adsorption of these metal ions on the unmodified PEG-MA gel beads was zero. The maximum adsorptions of heavy metal ions onto the Cibacron Blue F3GA-attached microbeads from single solutions were 23.3 mg/g (112.4 mumol/g) for Pb(II), 12.4 mg/g (110.3 mumol/g) for Cd(II), and 7.0 mg/g (110.2 mumol/g) for Cu(II). When the heavy metal ions competed (in the case of the adsorption from their mixture) the amounts of adsorption were 14.96 mg/g (72.2 mumol/g) for Pb(II), 0.72 mg/g (11.3 mumol/g) for Cu(II), and 1.10 mg/g (9.8 mumol/g) for Cd(II). Under competitive conditions, the system showed high selectivity for Pb(II) ions. The formation constants of Cibacron Blue F3GA-metal ion complexes were investigated through the application of the Ruzic method. The calculated values of formation constants were 8.5 x 10(5) L/mol(1) for Pb(II) dye, 2.5 x 10(5) L/mol for Cu(II) dye, and 8.2 x 10(4) L/mol for the Cd(II) dye complex. PEG-MA gel beads carrying Cibacron Blue F3GA can be regenerated through washing with a solution of nitric acid (0.1 mol/L). The maximum regeneration value was as high as 98.5%. These PEG-MA gel beads are suitable for more than 3 adsorption-desorption cycles without experiencing considerable loss of adsorption capacity.