The facilitated transport of Cu(II), Zn(II), Co(II), and Ni(II) ions from different aqueous nitrate source phases (c_Me = 0.001M, pH 6.0) across polymer inclusion membranes (PIMs) consisting of cellulose triacetate (support) and 2-nitrophenylpentyl ether (plasticizer) doped with 1-decyl-2-methylimidazol as ion carrier was reported. The membrane is characterised by atomic force microscopy (AFM) and thermal analysis (DTA and TG) techniques. The results show that Cu²⁺ can be separated very effectively from other transition metal cations as Zn²⁺, Co²⁺, and Ni²⁺ from different equimolar mixtures of these ions. The recovery factor of Cu²⁺ ions during transport across PIM from different mixture is equal to 92- 95.1%. The comparative transport of Cu(II), Zn(II), Co(II), and Ni(II) ions from aqueous nitrate source phase across supported (SLMs) containing 1-decyl-2-methylimidazol as ion carrier was reported.