Removal of heavy metals by electrodialysis using polyanilines prepared in hydrochloric acid and ionic liquids

Polyaniline (PANI) was synthesized in HCl (1 M) and in the presence of two ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate (BMimBF(4)) and 1-hexyl-2,3-dimethylimidazolium chloride ([HMMim][Cl]). The resulting polymers (PANI and PANI doped by ionic liquids) were associated to polyvinyl alcohol to prepare cation-exchange membranes. The membranes were characterized by optical microscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetry analysis. After characterization, the membranes were applied to the elimination of heavy metals (copper, lead, and cadmium) in aqueous solutions via electrodialysis. The results showed extraction percentages comprised between 80.63 and 96.04 % (for Cu2+), 87.89 and 99.55 % (for Pb2+), and 68.53 and 88.03 % (for Cd2+).

Automated summary

Polyaniline was synthesized in the presence of two ionic liquids and used to prepare cation-exchange membranes for the removal of heavy metals. The membranes showed extraction percentages ranging from 80.63% to 96.04% for Cu2+, 87.89% to 99.55% for Pb2+, and 68.53% to 88.03% for Cd2+.