Separation/Competitive Transport of Heavy Metal Ions across the Bulk Liquid Membranes with N,N',N''-Tris(4-methylphenyl)phosphoric Triamide As Carrier

摘要

The competitive bulk liquid membrane transport of seven metal ion by N,N',N''-tris(4-methylphenyl) phosphoric triamide carrier was studied using a flame atomic absorption spectrometry. Dichloromethane (DCM), chloroform (CHCl_3), nitrobenzene (NB) and 1,2-dichloroethane (1,2-DCE) solvents have been used as bulk liquid membranes (BLM). The carrier has been shown the maximum transport rate for Cu~(2+) cation in all of the BLM systems (except of 1,2-DCE) in comparison to the other cations containing Co~(2+), Cd~(2+), Ag~+, Pb~(2+), Ni~(2+), Cu~(2+), and Zn~(2+). The obtained results show that the selectivity and efficiency of transport in presence of this ligand change with the type of organic solvents. Various factors that affect the transport efficiency of this heavy metal cations have been optimized in order to obtain maximum transport. The complexation process between phosphoric triamide and Cu~(2+)cation have also been examined by conductomery method. The stoichiometry of the complex and the formation constant of phosphoric triamid-Cu~(2+) complex have been determined.