Evaluation of Jeffamine® core PAMAM dendrimers for simultaneous removal of divalent heavy metal ions from aqueous solutions by polymer assisted ultrafiltration

Abstract

Different generations (G3-G4) of amine-terminated Jeffamine® T-403 core poly(amidoamine) PAMAM dendrimers (JCPDs) were used as new macromolecular heavy metal chelating agent templates in polymer assisted ultrafiltration (PAUF) for the investigation of their removal ability for some of the divalent metal ions: Cu, Co, Ni, Cd, and Zn from aqueous solutions under competitive conditions. The effects of pH and generation size of JCPDs were also investigated. Extent of binding (EOB) data can be appropriately expressed by a tetradentate coordination for JCPDs at pH 9 where the maximum removal of metal ions was observed. At pH 9.0, the affinity of both generations towards heavy metal ions was also observed in the decreasing order of Zn(II) > Co(II) > Ni(II) > Cu(II) > Cd(II). Results revealed that the highest total binding capacity was observed for G3-NH2 (262.79 ± 1.62 mg/g) as a little bit higher than that of G4-NH2 (257.27 ± 2.57 mg/g). EOB studies also proved the active contribution of amide groups to metal binding ability of PAMAMs. Both generations were selective towards Cu(II) ions at lower pH 5 and pH 7. From these results, it was concluded that studied JCPDs have the desired technical properties to be used for the removal of toxic metals from wastewaters.

Keywords

• Poly(amidoamine) PAMAM dendrimers
• Jeffamine® T-403
• liquid phase retention (LPR)
• metal complexation
• removal of heavy metals