Recovery of gold ions from discarded mobile phone leachate by solvent extraction and polymer inclusion membrane (PIM) based separation using an amic acid extractant

A facilitated transport of Pb(II) through polymer inclusion membrane (PIM) containing 1,8,15,22-tetra(1-heptyl)-calixresorcin[4]arene and its tetra- and octasubstituted derivatives containing phosphoryl, thiophosphoryl or ester groups as an ion carrier was investigated. The efficiency of Pb(II) removal from aqueous nitrate solutions was considered as a function of the composition of membrane (effect of polymer, plasticizer, and carrier), feed (effect of initial metal concentration and presence of other metal ions) and stripping phases, and temperature of the process conducting. Two kinetic models were applied for the transport description. The highest Pb(II) ions removal efficiency was obtained for the membrane with tetrathiophosphorylated heptyl-calixresorcin[4]arene as an ion carrier. The activation energy value, found from Eyring plot to be equal 38.7 ± 1.3 kJ/mol, suggests that the transport process is controllable both by diffusion and chemical reaction. The competitive transport of Pb(II) over Zn(II), Cd(II), and Cr(III) ions across PIMs under the optimal conditions was also performed. It was found that the Cr(III) ions’ presence in the feed phase disturb effective re-extraction of Pb(II) ions from membrane to stripping phase. Better stability of PIM-type than SLM-type membrane was found.

Download Full-text

Optical sensing membrane for determination of trace cadmium(II), zinc(II) and copper(II) based on immobilization of 1-(2-pyridylazo)-2-naphthol on polymer inclusion membrane

Microchemical Journal ◽

10.1016/j.microc.2020.105767 ◽

2021 ◽

Vol 162 ◽

pp. 105767

Author(s):

Xiaorong Meng ◽

Xiaojing Jiang ◽

Yiwen Long ◽

Jin Chen ◽

Lei Wang ◽

...

Keyword(s):

Optical Sensing ◽

Inclusion Membrane ◽

Polymer Inclusion Membrane ◽

Trace Cadmium ◽

Sensing Membrane

Download Full-text

Extraction of tetra- and hexavalent actinide ions from nitric acid solutions using some diglycolamide functionalized calix[4]arenes

Radiochimica Acta ◽

10.1515/ract-2020-0100 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Rajesh B. Gujar ◽

Parveen K. Verma ◽

Prasanta K. Mohapatra ◽

Mudassir Iqbal ◽

Jurriaan Huskens ◽

...

Keyword(s):

Nitric Acid ◽

Solvent Extraction ◽

Extraction Efficiency ◽

Minor Actinide ◽

Acid Solutions ◽

Extraction Mechanism ◽

Nitrate Ion ◽

Nitric Acid Solutions ◽

Actinide Ions ◽

Acid Extractant

Abstract Neptunium is one of the most important minor actinide elements with some of its isotopes having very long half-lives, therefore necessitating its separation from acidic radioactive wastes. Solvent extraction of Np4+ and NpO2 2+ was studied using three multiple diglycolamide (DGA) extractants with n-propyl, n-octyl and 3-pentyl substituents termed as L I , L II and L III , respectively, in a mixed diluent of 5% isodecanol and 95% n-dodecane. For comparison purpose, the extraction of Pu4+ and UO2 2+ was carried out under identical conditions. The extraction efficiency of the ligands for the tetravalent ions followed the trend: L II > L I > L III , which changed to L III > L II > L I for the hexavalent ions. While the extraction of the tetravalent ions was reasonably good (ca. 90–98%) with an extremely low (5.0 × 10−5 M) ligand concentration, poor extraction (ca. 5–16%) of the hexavalent ions was seen even with a 20 times higher concentration of the ligand. In general, Pu4+ was better extracted than Np4+, while NpO2 2+ was marginally better extracted then UO2 2+. A ‘solvation’ type extraction mechanism was proposed based on the extraction profiles obtained as a function of the concentrations of the feed nitric acid, extractant as well as nitrate ion. The extracted species were found out to be M(NO3)4·mL and MO2(NO3)2·nL (M = Np or Pu, 1 < m < 2, n ≃ 1).

Download Full-text