Cezary Kozlowski

Competitive transport of toxic metal ions by polymer inclusion membranes

The paper gives a short overview of application of polymer inclusion membranes (PIMs) for separation and removal of metal ions. Investigation of the selective removal of toxic metal ions, i.e. Cr(VI), Cd(II), Zn(II) from acidic chloride aqueous solutions, as well as trace radionuclides, i.e., 137Cs, 90Sr and 60Co from wastewaters using transport across polymer inclusion membranes was studied. The carriers, i.e., tri-n-octylamine for anionic metal species, as well as dibenzo-21-crown-7, tertbutyl-dibenzo-21-crown-7, and dinonylnaphtalenesulfonic acid for metal cations were incorporated into polymer inclusion membranes composed of cellulose triacetate as a support and o-nitrophenyl pentyl ether as a plasticizer. Selective transport of chromium(VI) over zinc(II) and cadmium(II) chloride complexes through PIMs was observed. Competitive transport of trace radionuclide ions, i.e., 137Cs, 90Sr, and 60Co from NaNO3 aqueous solutions across polymer inclusion membranes containing a mixture of dinonylnaphtalenesulfonic acid, and dibenzo-21-crown-7 as the carrier provide the selectivity order Cs(I)>Sr(II)>Co(II).

Removal of toxic metal ions from landfill leachate by complementary sorption and transport across polymer inclusion membranes

In this study, performance of a lab-scale two-step treatment system was evaluated for removal of toxic metal ions from landfill leachate. The technology of polymer inclusion membranes (PIMs) was the first step, while the second step of the treatment system was based on sorption on impregnated resin. The PIMs were synthesized from cellulose triacetate as a support, macrocyclic compound i.e. alkyl derivative of resorcinarene as a ionic carrier and o-nitrophenyl pentyl ether as a plasticizer. The transport experiments through PIM were carried out in a permeation cell, in which the membrane film was tightly clamped between two cell compartments. The sorption tests were carried out using a column filled with a resin impregnated with resorcinarene derivative. The obtained results show the good performance with respect to the removal of heavy metals from landfill leachate with the overall removal efficiency of 99%, 88% and 55% for Pb(II), Cd(II) and Zn(II) ions, respectively. Moreover the contents of metal ions in the leachate sample after treatment system were below permissible limit for wastewater according to the Polish Standards.

Sorption of Pb(II), Cd(II) and Zn(II) performed with the use of carboxyphenylresorcinarene-impregnated Amberlite XAD-4 resin

AbstractA 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 60u2009min, and at initial Pb(II) concentration equal to 10u2009mg/L. The extraction capacity for Pb(II) in the batch system was 107.6u2009mg/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)u2009>>u2009Cd(II), Zn(II). The values of correlation coefficients (R2) indicated that the Langmuir isotherm model well-described the sorp...

Calixarene-based extractants for heavy metal ions removal from aqueous solutions

ABSTRACT The article reviews the literature on the possibility of application of the calixarene-based compounds for selective separation of toxic heavy metals from aqueous solutions by the solvent extraction and transport across liquid membranes. The specific three-dimensional structure of calixarenes and their derivatives, simple and low-cost synthesis, and ease of chemical transformation qualify these compounds for the role of selective chemical extractants of toxic heavy metal ions present in industrial wastewater. This article analyses the influence of various process factors, with the greatest emphasis on the structure of the extractants/carriers, on efficient separation of heavy metal ions, primarily those most commonly found in galvanic wastewater.

Application of O-phenylacetyl β-CD as a carrier for selective transport of lead(II) across polymer inclusion membranes

AbstractThe 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 transporte...

Removal of gold(III) from hydrochloric acid solutions using N-(diethylthiophosphoryl)-aza[18]crown-6 immobilized into membranes and Amberlite XAD-4 resin

ABSTRACT In this study experiments were performed to evaluate the Au(III) removal efficiency using a novel ion carrier – N-(diethylthiophosphoryl)-aza[18]crown-6 immobilized into polymer inclusion membranes (PIMs) and Amberlite (XAD-4) resin. This lariat ether, applied in the membrane and in solid phase extraction (SPE) systems, was used for the transport and removal of gold(III) from chloride solutions. Several influencing factors, such as solution acidity, the amount of extractant, the concentration of Au(III) ions, stripping agents and metal ions’ recovery behaviour, were investigated. It was found that the lariat ether immobilized in membranes and Amberlite XAD-4 resin effectively extracted gold from chloride aqueous media. Under optimal conditions, the Au(III) removal efficiencies for PIM and impregnated resin were 98.9 and 92.9%, respectively.