The Application of 2,6-Bis(4-Methoxybenzoyl)-Diaminopyridine in Solvent Extraction and Polymer Membrane Separation for the Recovery of Au(III), Ag(I), Pd(II) and Pt(II) Ions from Aqueous Solutions

• Published in: International journal of molecular sciences 2021-08, Vol.22 (17), p.9123
• Main Authors: Bożejewicz, Daria, Witt, Katarzyna, Kaczorowska, Małgorzata A, Urbaniak, Włodzimierz, Ośmiałowski, Borys
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Cations - chemistry; Cations - isolation & purification; Chemical compounds; Dynamic stability; Gold; Gold - isolation & purification; Industrial wastes; Ions; Leaching; Ligands; Membrane separation; Membranes; Metal ions; Metals; Metals, Heavy - chemistry; Metals, Heavy - isolation & purification; Noble metals; Palladium; Palladium - isolation & purification; Platinum - isolation & purification; Polymers; Separation; Silver; Silver - isolation & purification; Solvent extraction; Solvent extraction processes; Solvents; Spectrophotometry; Wastewater
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22179123

The work describes the results of the first application of 2,6-bis(4-methoxybenzoyl)-diaminopyridine ( ) for the recovery of noble metal ions (Au(III), Ag(I), Pd(II), Pt(II)) from aqueous solutions using two different separation processes: dynamic (classic solvent extraction) and static (polymer membranes). The stability constants of the complexes formed by the L with noble metal ions were determined using the spectrophotometry method. The results of the performed experiments clearly show that 2,6-bis(4-methoxybenzoyl)-diaminopyridine is an excellent extractant, as the recovery was over 99% for all studied noble metal ions. The efficiency of 2,6-bis(4-methoxybenzoyl)-diaminopyridine as a carrier in polymer membranes after 24 h of sorption was lower; the percentage of metal ions removal from the solutions (%R ) decreased in following order: Ag(I) (94.89%) > Au(III) (63.46%) > Pt(II) (38.99%) > Pd(II) (23.82%). The results of the desorption processes carried out showed that the highest percentage of recovery was observed for gold and silver ions (over 96%) after 48 h. The results presented in this study indicate the potential practical applicability of 2,6-bis(4-methoxybenzoyl)-diaminopyridine in the solvent extraction and polymer membrane separation of noble metal ions from aqueous solutions (e.g., obtained as a result of WEEE leaching or industrial wastewater).