Membrane Extraction of Bi( III ) by a Cellulose Triacetate/Poly(Vinylidene Fluoride‐Co‐Hexafluoropropylene) Blend Polymer Inclusion Membrane

The ability of a blend polymer inclusion membrane (BPIM) including cellulose triacetate (CTA) and poly(vinylidene fluoride‐co‐hexafluoro propylene) (PVDF‐HFP) polymers was investigated for the selective extraction of Bi(III) as its anionic chloride complexes. The BPIM composed of CTA (30 wt%), PVDF‐HFP (35 wt%), tri‐ n ‐octylamine (TOA, 25 wt%), and the plasticizer tri‐ n ‐butylphosphate (TBP, 10 wt%) bore the criteria required for achieving the designed target of the study. Conventional techniques gave information for the characterization of the prepared BPIM. A circular BPIM piece (3.5 cm in diameter) quantitatively extracted Bi(III) (20 mg L −1 ) from 50 mL of a 0.3 mol L −1 HCl solution after 120 min of shaking. Successful recovery was achieved by 50 mL of Na 2 CO 3 /EDTA (0.4/0.1 mol L −1 ). The data analysis confirmed the extraction of Bi(III) is taken place via the formation of the ion pair [TOAH + ] 2 [BiCl 5 2− ]. Under the selected conditions, the BPIM exhibited selective extraction of Bi(III) in the presence of various metal ions, including Cu(II), Fe(III), Cr(III) Co(II), Zn(II), Pb(II), Cd(II), and Ni(II), although Cd(II) slightly interfered with this selectivity. The applicability of the proposed BPIM was evaluated by its use for the recovery of bismuth from the residue of a zinc plant production.