Effective Extraction of Zn(II) Ions Using Aqueous Two-Phase Partitioning

Abstract

This study evaluates the influence of various process parameters such as type of aqueous two-phase systems, phase forming salt, molecular weight of the phase forming polymer, phase composition, phase volume ratio, type of neutral salts and temperature on the extraction yield of Zn (II) ions to determine the best conditions for the recovery of Zn (II) ions in aqueous two-phase systems (ATPS) composed of by poly(ethylene glycol) (PEG) and a salt (sodium sulphate, ammonium sulphate, potassium citrate and sodium citrate).In all the systems, Zn (II) ions presented affinity for the PEG-rich phase. The 31.36% PEG 2000 + 7.45% sodium citrate system with NaCl showed the highest values of extraction yield. In addition, thermodynamic parameters (ΔH• t , ΔS• t , ΔG• t ) as a function of temperature, were calculated for this system and the results implied that the partitioning of Zn (II) ions was controlled by entropy changes.

Aqueous Biphasic Systems Based on Ethyl Lactate: Molecular Interactions and Modelling

“…In addition, the presence of surfactants was reported to enhance the formation of two phases (Batista et al 2021). Compared to traditional organic solvent/water extractions, both phases in ABS are rich in water, providing a suitable environment for biologically active substances (Banik et al 2003;Sun et al 2012) and extraction of different compounds such as metals (Khayati and Mohamadian 2016;Ferreira et al 2021), alkaloids (Pereira et al 2013], dyes and pesticides (Oke and Ijardar 2021), phenolic compounds (Xu et al 2021], etc.…”