Multi-templated Pb-Zn-Hg Ion Imprinted Polymer for the Selective and Simultaneous Removal of Toxic Metallic Ions from Wastewater

Abstract

A multi-templated Pb-Zn-Hg ion imprinted polymer was synthesized to demonstrate the selective and simultaneous removal of the named targeted ions. Molecular Imprinting Technology was employed, guided by thermal bulk polymerization method, methacrylic acid as the functional monomer and ethylene glycol dimethylacrylate as crosslinking agent in the presence of the initiator azobisisobutyronitrile; Pb(II), Zn(II) and Hg(II) ions as template ions, and 1,10-phenanthroline as the complexing agent. Rigorous, optimal template removal method was employed. Physical and chemical properties of the sorbent were investigated using Fourier Transform Infrared Spectroscopy, X-ray Diffraction and Atomic Force Microscopy. Operational parameters: time, pH and sorbent dosage for the rebinding batch experiments were optimized and found to be 15 min, 7.5 and 666.7 mg/L respectively. Percentage recoveries of the removed targeted ions from spiked samples were: 92.14 ± 0.16%, 106.09 ± 0.17% and 99.86 ± 0.04%. The synthesized sorbents showed good selectivity towards the targeted metal ion by removing 90% - 98% of the templated ions as compared to 58% - 62% of the competitive ions.