Removal of zinc(II) and iron ions from chloride solutions with phosphonium ionic liquids

► Phosphonium ILs: Cyphos IL 101 and 104 effectively extract Zn(II) and Fe(III). ► Cyphos IL 101 is applied in polymer inclusion membrane as Zn(II) and Fe(III) carrier. ► Fe(III) is transported through the membrane significantly faster than Zn(II). ► Fe(III) separation from Zn(II) is probable because of difference in transport rate.