Application of a deep eutectic mixture and ionic liquid as carriers in polymer adsorptive membranes for removal of copper(II) and zinc(II) ions from computer scrap leachates

This paper describes the results of the application of Aliquat 336 ionic liquid (IL-A) and a deep eutectic mixture consisting of diacetamide and Aliquat 336 (DEM-DA) as carriers in polymer adsorptive membranes (PAMs) used to remove copper(II) and zinc(II) ions from aqueous solutions obtained by leaching computer pins with strong acids. The wettability of the formulated PAMs containing poly(vinyl chloride) as a polymer matrix and bis(2-ethylhexyl) adipate as a plasticizer was examined. Using DEM-DA-containing polymer membrane recovered approximately 97% of copper(II) and 96% of zinc(II) ions after 1 h of separation processes, whereas application of IL-A-containing PAM allowed the removal of similar amounts of copper(II) and zinc(II) ions after 3 h. The high efficiency of PAMs was confirmed by the analysis of their chemical composition after the separation processes by wavelength-dispersive X-ray fluorescence spectroscopy. The use of PAMs containing a deep eutectic mixture (DEM) as an ion carrier allows for a reduction of the separation time, which can be of significant economic importance, especially in case of processes carried out on a larger scale. Due to its properties, DEM is considered safe for the natural environment, and its use as a carrier in PAMs represents the so-called "Green Chemistry".