Poly(N-hydroxymethyl acrylamide-co-acrylic acid) and poly(N-hydroxymethyl acrylamide-co-acrylamidoglycolic acid): synthesis, characterization, and metal ion removal properties

Macroreticular chelating resins containing carboxylic groups, poly(N-hydroxymethyl acrylamide-co-acrylic acid) P(HMA-co-AA) and poly(N-hydroxymethyl acrylamide-co-2-acrylamido glycolic acid) P(HMA-co-AGA) were synthesized by solution radical polymerization with ammonium persulfate as initiator and N,N'-methylene-bis-acrylamide as cross-linking reagent. The polymerization yield was 98.9 and 91.9% for P(HMA-co-AA) and P(HMA-co-AGA), respectively. The retention properties were studied under competitive and noncompetitive conditions by batch equilibrium procedure for the following metal ions: Cd(II), Cr(III), Zn(II), Pb(II), and Hg(II). The effects of pH, time, temperature, and initial ion concentration on adsorption were investigated. The resins showed a significant ability to retain Pb(II), greater than 79%, at pH 5.