光度法研究聚乙二醇-硫酸铵-邻苯三酚红体系中铋(Ⅲ), 铁(Ⅲ), 铜(Ⅱ), 镍(Ⅱ), 钴(Ⅱ), 铅(Ⅱ)的萃取分离

本文研究了在聚乙二醇(PEG)-硫酸铵[(NH_4)_2SO_4]-邻苯三酚红(PR)体系中Bi(Ⅲ),Fe(Ⅲ),Cu(Ⅱ),Ni(Ⅱ),Co(Ⅱ),Pb(Ⅱ)的萃取行为。实验结果表明,Bi(Ⅲ)在pH3.5～6.5及Fe(Ⅲ)在pH4.0～7.0范围内可以被PEG相几乎完全萃取,而Cu(Ⅱ),Co(Ⅱ)在pH1.0～7.0,Pb(Ⅱ)在pH2.0～7.0,Ni(Ⅱ)在pH1.0～4.5则不被萃取。从而实现了将Bi(Ⅲ)(pH3.5),Fe(Ⅲ)(pH5.0)与Cu(Ⅱ),Co(Ⅱ),Pb(Ⅱ),Ni(Ⅱ)混合离子的定量分离。同时探讨了PEG相的萃取机理。

Study on Extraction Separation of Bi(Ⅲ), Fe(Ⅲ), Cu(Ⅱ), Ni(Ⅱ), Co(Ⅱ) and Pb(Ⅱ) in PEG-(NH4)2SO4-PR System Using Spectrophotometry

In polyethylene PEG-(NH4)2SO4-PR system the extraction separation behaviour of the complexes of Bi(III), Fe(III), Cu(II), Ni(II), Co(II) and Pb(II) was investigated. The results indicated that Bi in pH 3.5-6.5 and Fe(III) in pH 4.0-7.0 were almost completely extracted by the PEG phase, while Cu(II) and Co(II) in pH 1.0-7.0, Pb(II) in pH 2.0-7.0, and Ni(II) in pH 1.0-4.5 were not extracted by the PEG phase. So Bi(III) (pH 3.5) and Fe(III) (pH 5.0) were quantitatively separated from the mixed solution of Bi(III), Fe(III), Cu(II), Co(II), Pb(II) and Ni(II) ions. The extraction mechanism for PEG phase was preliminarily studied.