A study on the adsorption characteristics of Pb(II), Cd(II) and Zn(II) cations onto carboxyphenylresorcinarene-impregnated resin in batch and fixed bed column systems has been conducted. Results of the batch and fixed bed column systems confirm that impregnated resin is a good adsorbent for Pb(II) and a poor one for Cd(II) and Zn(II) ions. Solid phase extraction (SPE) of Pb(II), Cd(II) and Zn(II) was conducted in batch system under various pH, interaction times, and metal concentrations. It was found that SPE of Pb(II) was optimal at pH 6.5 at contact time of 60 min, and at initial Pb(II) concentration equal to 10 mg/L. The extraction capacity for Pb(II) in the batch system was 107.6 mg/g, i.e. 99.7%. On the other hand, the SPE of Cd(II) and Zn(II) under optimal conditions has shown much smaller extraction capacities. Selectivity order of extracted metal ions was Pb(II) >> Cd(II), Zn(II). The values of correlation coefficients (R²) indicated that the Langmuir isotherm model well-described the sorption equilibrium. Application of Temkin sorption model to the experimental data revealed that the mechanism of adsorption of metal ions onto resorcinarene-impregnated resin was physisorption. The column test also confirmed the results of batch tests and showed that the total uptake of Pb(II) was 104.4 mg/g. The carboxyphenyl resorcinarene derivative-impregnated resin has been found efficient and easily regenerative and can be used several times.

Cellulose-triacetate-based polymer inclusion membranes (PIMs) with different concentrations of a calixpyrrole ester derivative as the membrane carrier were studied to determine their ability to transport Ag(I) from aqueous nitrate solutions. The effects of the concentrations of ion carriers and metal ions, the pH of the source aqueous phase, and stripping agents on the effective transport of Ag(I) were assessed. All studied parameters were found to be important factors for the transport of Ag(I) metal ions. The initial fluxes were determined at different temperatures. The prepared membranes were found to be highly permeable. The selectivity of silver transport from an aqueous solution containing Ag(I), Cu(II), Pb(II), Cd(II), Ni(II), Zn(II), and Co(II) ions was also investigated.

Stricter environmental regulations regarding the discharge of toxic metals require developing various technologies for the removal of these metals from polluted effluents. The removal of toxic metal ions using immobilized membranes with doped ligands is a promising approach for enhancing environmental quality, because of the high selectivity and removal efficiency, high stability, and low energy requirements of the membranes. Cellulose triacetate-based polymer inclusion membranes (PIMs), with calix[4]resorcinarene derivative as an ion carrier, were analyzed to determine their ability for removal of Pb(II) ions from aqueous solutions. The effects of ion carrier concentration, plasticizer amount, pH of source aqueous phase, and receiving agents on the effective transport of Pb(II) were determined. All studied parameters were found to be important factors for the transport of Pb(II) ions. The PIM containing calix[4]resorcinarene derivative as an ion carrier showed high stability and excellent transport activity for selective removal of Pb(II) from the battery industry effluent, with a separation efficiency of 90%.

The o-phenylacetyl β-CD derivative 1 was obtained by substitution of β-CD and characterized by spectroscopic methods. Competitive transport of equimolar mixtures of Pb(II), Cd(II), Cu(II), and Na(I) ions from aqueous nitrate feed phase across polymer inclusion membranes (PIMs) using O-phenylacetyl β-CD 1 derivative as an ion carrier has been investigated. The influence of the phenylacetyl groups attached to β-CD rings on the selectivity and efficiency of metal ions transport across PIMs containing cellulose triacetate (CTA) as the support was studied. The efficiency of a membrane for the selective transport of Pb(II) ions has been investigated, and several parameters affecting metal transport have been evaluated, such as the carrier concentration, the plasticizer content, and the acidity of the aqueous phase. We found that facilitated transport of metal ions across the above PIMs proceeds via a carrier-mediated mechanism and is dependent on pH-driving force. PIMs including 1 selectively transported Pb(II) ions at concentration of ion carrier in membrane equal to 0.6 M and have shown the preferential selectivity order: Pb(II) >> Cd(II) > Cu(II) > Na(I). The repeated transport experiments of PIM indicated the long-term integrity of PIM.