Metal ion removal from aqueous solution by liquid phase polymer-based retention technique

Water-soluble poly[3-(dimethylamino)propylacrylate] is synthesized by radical polymerization with a yield Of 87%. The polymer structure is confirmed by FT-IR and H-1-NMR spectroscopies. The polymer lost only 3% of weight up to 100 degrees C. The narrowest molecular weight distribution is observed with the fraction between 3,000 and 10,000 Da. P(DAPA) presents a high affinity for the metal ions Pb2+ and Cu2+, while the other metal ions are not significantly retained. By increasing the filtration factor, Z, metal ion affinity decreases, indicating a very weak ligand-metal interaction and the possibility of its destruction when washed with water at the filtration cell's pH. For Z = lo, the retention values of Pb2+ and Cu2+ at pH 5 are 76.5% and 48.5%, respectively, while the values for Cu2+ and Cd2+ at pH 7 are 89.5% and 40.4%, respectively.