CIBACRON-BLUE F3GA-INCORPORATED MACROPOROUS POLY(2-HYDROXYETHYL METHACRYLATE) AFFINITY MEMBRANES FOR HEAVY-METAL REMOVAL

Macroporous poly(2-hydroxyethyl methacrylate), poly(HEMA), membranes w ere prepared by UV-initiated photo-polymerization of HEMA in the prese nce of an initiator (azobisisobutyronitrile, AIBN). An affinity dye, i .e., Cibacron Blue F3GA was then incorporated covalently. These affini ty membranes with a swelling ratio of 58%, and carrying 10.67 mmol Cib acron Blue F3GA/m(2) membrane were used in the adsorption/desorption o f some selected heavy metal ions [i.e., As(III), Cd(II) and Pb(II)] fr om aqueous media. Very high adsorption rates were observed and adsorpt ion equilibria were reached in about 30 min. The maximum adsorptions o f heavy metal ions onto the dye-incorporated affinity membranes from t heir single solutions were 12.6 mmol/m(2) for As(III), 61.0 mol/m(2) f or Cd(II) and 79.0 mol/m(2) for Pb(II), However, when the heavy metal ions competed (in the case of the adsorption from their mixture) the a mounts of adsorption for As(III), Cd(II) and Pb(II) were quite close. Desorption of heavy metal ions was carried out by using 0.1 M HNO3 (pH 1.0). Up to 95% of the adsorbed heavy metal ions were desorbed in 60 min. Repeated adsorption/desorption cycles showed the feasibility of t his novel affinity membrane for heavy metal removal.