Bulk Liquid Membrane Transport Research Articles

Effect of the nitrile group in extraction and bulk liquid membrane transport of amino acids

Effect of the nitrile group in extraction and bulk liquid membrane transport of amino acids

Separation/Competitive Transport of Heavy Metal Ions across the Bulk Liquid Membranes with N,N',N''-Tris(4-methylphenyl)phosphoric Triamide As Carrier

The competitive bulk liquid membrane transport of seven metal ion by N,N',N''-tris(4-methylphen-yl)phosphoric triamide carrier was studied using a flame atomic absorption spectrometry. Dichloromethane (DCM), chloroform (CHCl3), nitrobenzene (NB) and 1,2-dichloroethane (1,2-DCE) solvents have been used as bulk liquid membranes (BLM). The carrier has been shown the maximum transport rate for Cu2+ cation in all of the BLM systems (except of 1,2-DCE) in comparison to the other cations containing Co2+, Cd2+, Ag+, Pb2+, Ni2+, Cu2+, and Zn2+. The obtained results show that the selectivity and efficiency of transport in presence of this ligand change with the type of organic solvents. Various factors that affect the transport efficiency of this heavy metal cations have been optimized in order to obtain maximum transport. The complexation process between phosphoric triamide and Cu2+cation have also been examined by conductomery method. The stoichiometry of the complex and the formation constant of phosphoric triamid-Cu2+ complex have been determined.

Efficient extraction and recovery of Lignosulfonate using sunflower oil as green solvent in liquid membrane transport: Equilibrium and kinetic study

This work highlights extraction and removal of Lignosulfonate using sunflower oil-Tri-n-octylamine (TOA) system in bulk liquid membrane transport. Maximum extraction and recovery percentages of 92.4% and 75.2% were achieved. Optimum manifold operating conditions were: 4vol.% TOA, 2±0.1 feed phase pH, 300rpm stirring speed, at 40°C with 0.2 (M) Na2SO4 solution. 1:2 (organic/aqueous) and 1:1 (aqueous/aqueous) phase ratios produced best results. Extraction (36.85kJ/mol) was found to be intermediate controlled and stripping (54.79kJ/mol) was chemical reaction controlled. Kinetic estimation of data with higher rate constants for stripping vis-à-vis extraction showed latter to be rate determining.

Effective removal of Congo red using sunflower oil/tri-n-octylamine system in a bulk liquid membrane process and studying the transport kinetics

The present work highlights effective transport and removal of Congo red (CR) from its model solution using sunflower oil/tri-n-octylamine (TOA) system in bulk liquid membrane (BLM) transport. Aqueous solution of Na2CO3 with 1 M solution strength was found to be an effective stripping medium for the anionic dye transport. Maximum extraction and recovery percentages of 99.9 and 75.6% were achieved when optimum manifold operating conditions were: 4 vol.% TOA, 2 ± 0.1 feed phase pH, 300 rpm stirring speed, at 40 °C temperature with 8 h, equilibrium time. Kinetic estimation of data with higher rate constants for extraction vis-a-vis stripping operation throughout various experimental conditions suggested that CR transport across sunflower oil/TOA BLM system was governed by stripping process. Activation energies for extraction and stripping operations were found to be 45.92 and 74.05 kJ mol−1, respectively. This led to a conclusion that the rate determining step for extraction was intermediate controlled whereas for stripping it was chemical reaction rate controlled. Finally, spectral studies (UV–vis and FT-IR) were carried out to confirm and validate the recovery of CR.

Separation study of Mg+2 from seawater and RO brine through a facilitated bulk liquid membrane transport using 18-Crown-6

A facilitated bulk liquid membrane transport approach is studied for Mg(II) extraction from seawater and reversed osmosis brine simulated media using 18-Crown-6 and dibenzo (DB)-18-Crown-6. The work is based on investigating the experimental parameters affecting the transport efficiency, such as pH of feed and receiving phase, type of membrane solvent, temperature, type and concentration of the carrier, and stripping solution conditions. The transported amount of magnesium ions from feed phase (Mg(II) = 0.059 M, NaCl = 0.01 M, pH = 3.3) across a chloroform membrane (18C6 = 0.001 M) into the receiving phase (SCN− 0.1 M pH 3) was found to be %97 (±0.7) after 2.5 hr. The selectivity of the method was evaluated by performing competitive transport experiments on the mixtures containing Ca2+, Na+, K+, and Mg2+ ions.

Selective Separation of Silver(I) Ion Through a Bulk Liquid Membrane Containing 1,1'-(1,3-Phenylene)bis(3-allylthiourea) as Carrier

The competitive bulk liquid membrane transport of six metal cations from an aqueous source phase (SP) containing Ag+, Pb2+, Cu2+, Zn2+, Co2+ and Ni2+ through an organic membrane phase (MP) facilitated by 1,1'-(1,3-phenylene)bis(3-allylthiourea) as a carrier into an aqueous receiving phase (RP) was studied and compared. Fluxes and selectivities for competitive metal cation transport have been determined in a variety of source solution pH and membrane solvent types. The obtained results showed that the carrier is selective for Ag+ cation. The effect of different experimental conditions that affect the transport efficiency were studied and optimized. In the optimum condition, the transport of a 5 × 10-4 mol L−1 solution of Ag+ cations was observed 92.3 ± 5.3% after 4 h in the presence of equimolar concentrations of other metal cations. A possible application of this carrier system and transport process for separation and recovery of Ag+ cation from real samples has also been examined.

Synthesis and crystal structure of a new N-(2,6-dichlorobenzoyl)-N′,N″-bis(pyrrolidinyl)-phosphoric triamide as a carrier and competitive bulk liquid membrane transport of six metal cations

The competitive metal ion transport experiments of Co+2, Cd+2, Ag+, Pb+2, Ni+2, and Cu+2 were carried out by N-(2,6-dichlorobenzoyl)-N′,N″-bis(pyrrolidinyl)-phosphoric triamide as a carrier in organic membrane phase. 2,6-Cl2C6H3C(O)NHP(O)[NC4H8]2 has been synthesized and characterized by mass spectrometry IR spectroscopy and single crystal X-ray diffraction. The asymmetric unit of title phosphoric triamide contains one symmetrically independent molecule. The source phase contained equimolar concentrations of metal ions at pH 5 and the receiving phase being buffered at pH 3. The following solvents were examined as membrane: chloroform (CHCl3), nitrobenzene (NB), 1,2-dichloroethane (1,2-DCE), dichloromethane (DCM), dichloromethane/1,2-dichloroethane (DCM/1,2-DCE). The obtained results show that the selectivity and efficiency of transport for these heavy metal cations change with the nature of the ligand and also the organic solvents, which were used as liquid membrane in these experiments. A good selectivity was observed for Pb+2 cation by this ligand in all membrane systems. Moreover, the selectivity of metal cations in DCM is higher than other solvents. A non-linear relationship was found between the percent of transport of Pb+2 cation by this ligand and the compositions of DCM/1,2-DCE and binary solution by this ligand. The effect of several factors such as the nature of carboxylic acids (stearic, fumaric and maleic acid) as surfactant in the membrane phase and the time of transport on transport efficiency of Pb+2 cation were investigated.

Calcium Selectivity in Liquid Membrane Transport using Anthraquinone Derived Redox Switched Synthetic Ionophores

Selective recognition of alkali and alkaline earth metal ion pairs viz.Li+, Na+, K+, Mg2+ and Ca2+ is of great biological importance. Design and synthesis of ionophores and receptor molecules capable of selectively binding and transporting substrates (neutral and ionic) are based on molecular recognition and used to develop membrane separation systems. This has potential applications in analytical, environmental, and biomimetic chemistry. We have designed and synthesized new series of anthraquinone derived single and double armed ionophores. Supermolecules have been isolated with these synthetic podands as host and metal ions as guest. Interaction has been confirmed by melting point (m.p.), infrared red (IR), and proton nuclear magnetic resonance (1H NMR) spectral analysis and cyclic voltammetric studies. Further, the liquid liquid extraction, bulk liquid membrane (BLM) transport, and supported liquid membrane (SLM) transport studies using polytetrafloroethylene membrane, cellulose nitrate membrane, onion membrane and egg shell membrane, have been done to find out the selectivity of these ionophores for various metal ions. Among the two liquid membrane systems used SLMs is more efficient than BLMs. It is found that double armed and bridged ionophores (A3 to A8) show better extraction ability than single armed ionophores (A1, A2) and ionophore A3 is calcium selective.

N-(Diisopropylthiophosphoryl)-N′-(R)-thioureas: synthesis, characterization, crystal structures and competitive bulk liquid membrane transport of some metal ions

Ten N-thiophosphorylated thioureas of the common formula RC(S)NHP(S)(OiPr)(2) [R = iPrNH (1), EtNH (2), Et(2)N (3), 2,5-Me(2)C(6)H(3)NH (4), 4-Me(2)NC(6)H(4)NH (5), 2-MeO(O)CC(6)H(4)NH (6), 2-PyNH (7), 2-PyCH(2)NH (8), 3-PyCH(2)NH (9), cyclo-C(2)H(2)N(3)NH (10)] have been synthesized and characterized by IR, NMR spectroscopy and elemental analysis. Molecular structures of 1 and 4-8 were elucidated by X-ray diffraction revealing linear, bi- or trifurcated intramolecular hydrogen bonds. Additionally, their crystal structures are stabillized by two intermolecular hydrogen bonds, which in turn lead to a centrosymmetric dimer formation. The hydrogen bonded dimers of 5-8 are packed to polymeric chains through the π···π stacking interactions between aryl or pyridyl rings. Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using 2-6 and 8-10 as the ionophore present in the organic phase. The source phase contained equimolar concentrations of Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II) with the source and receiving phases being buffered at pH = 5.5 and 1.0, respectively. The obtained data were compared with the transport and extraction properties of 1 and 7, which were described recently.

Thiophosphorylated bis-thioureas for competitive bulk liquid membrane transport of some metal ions

Eight N-thiophosphorylated bis-thioureas of the common formula Z[NHC(S)NHP(S)(OiPr) 2] 2 [Z = (1), 1,2-C 6H 4 (2), 1,3-C 6H 4 (3), 1,4-C 6H 4 (4), CH 2(1,4-C 6H 4) 2 (5), O(1,4-C 6H 4) 2 (6), S(1,4-C 6H 4) 2 (7), CH 2(1,4-C 6H 10) 2 (8)] have been synthesized and characterized by NMR spectroscopy and elemental analysis. Molecular structures of 3, 4, 5·0.5C 6H 14, 6·CH 2Cl 2 and 8 were elucidated by X-ray diffraction revealing two linear intramolecular hydrogen bonds. Their crystal structures are stabilized by four intermolecular hydrogen bonds, which in turn lead to a polymeric chain formation. Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using 1-8 as the ionophore present in the organic phase. © 2012 The Royal Society of Chemistry.

Competitive Bulk Liquid Membrane Transport of Heavy Metal Cations Using the 18-Crown-6 Ligand as an Ionophore

Competitive transport of Zn(II), Cd(II), Cr(III), Co(II), Ag(I), Pb(II), and Cu(II) cations from an aqueous source phase at pH 5 through bulk liquid membrane (BLM) containing 18-crown-6 (ion carrier), organic solvents chloroform, dichloromethane, 1,2-dichloroethane, and nitrobenzene, and chloroform–dichloromethane and chloroform–dichloroethane binary mixed solvents into an aqueous receiving phase at pH 3 has been investigated. The influence of the organic solvents and also the effect of some surfactants on the selectivity and transport efficiency of the metal cations through BLMs were studied. The obtained results show that the selectivity and the efficiency of transport for these heavy metal cations change with the nature of the organic solvents which were used as liquid membranes in these experiments. A good transport efficiency and high selectivity was observed for the Pb(II) cation under the experimental conditions in this investigation.

Separation study of some heavy metal cations through a bulk liquid membrane containing 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane

Competitive permeation of seven metal cations from an aqueous source phase containing equimolar concentrations of Co2+, Fe3+, Cd2+, Cu2+, Zn2+, Ag+ and Pb2+ metal ions at pH 5 into an aqueous receiving phase at pH 3 through an organic phase facilitated by 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane (Kryptofix5) as a carrier was studied as bulk liquid membrane transport. The obtained results show that the carrier is highly selective for Ag+ cation and under the employed experimental conditions, it transports only this metal cation among the seven studied metal cations. The effects of various organic solvents on cation transport rates have been demonstrated. Among the organic solvents involving nitrobenzene (NB), chloroform (CHCl3), dichloromethane (DCM) and 1,2-dichloroethane (1,2-DCE) which were used as liquid membrane, the most transport rate was obtained for silver (I) cation in DCM. The sequence of transport rate for this cation in organic solvents was: DCM>CHCl3>1,2-DCE>NB. The competitive transport of these seven metal cations was also studied in CHCl3–NB and CHCl3–DCM binary solvents as membrane phase. The results show that the transport rate of Ag+ cation is sensitive to the solvent composition and a non-linear relationship was observed between the transport rate of Ag+ and the composition of these binary mixed non-aqueous solvents. The influence of the stearic acid, palmitic acid and oleic acid as surfactant in the membrane phase on the transport of the metal cations was also investigated.

Metal-ion recognition-competitive bulk liquid membrane transport of transition and post-transition metal cations using a thioether donor acyclic ionophore

The competitive bulk liquid membrane transport of Cr3+, Co2+, Cu2+, Zn2+, Cd2+, Ag+ and Pb2+ metal cations with a new synthetic sulfur donor acyclic ligand (pseudo-cyclic ionophore), i.e. 1-(2-[(2-hydroxy-3-phenoxypropyl)sulfanyl]ethylsulfanyl)-3-phenoxy-2-propanol; (C20H26O4S2), was examined using some organic solvents as membranes. The membrane solvents include: chloroform (CHCl3), 1,2-dichloroethane (1,2-DCE), dichloromethane (DCM), nitrobenzene (NB), chloroform-nitrobenzene (CHCl3-NB) and chloroform-dichloromethane (CHCl3-DCM) binary mixtures. The transport process was driven by a back flux of protons, maintained by the buffering the source and receiving phases with pH 5 and 3, respectively. The aqueous source phase consisted of a buffer solution (CH3COOH/CH3COONa) at pH = 5 and containing an equimolar mixture of these seven metal cations. The organic phase contained the acyclic ligand, as an ionophore and the receiving phase consisted of a buffer solution (HCOOH/HCOONa) at pH = 3. For these systems that displayed transport behaviour, sole selectivity for Ag+ cation was observed under the employed experimental conditions in this investigation. The amount of Ag+ transported follows the trend: 1,2-DCE > CHCl3 > DCM > NB in the bulk liquid membrane studies. The transport of the metal cations in CHCl3-NB and CHCl3-DCM binary solvents is sensitive to the solvent composition. The influence of the stearic acid, palmitic acid and oleic acid in the membrane phase on the ion transport was also investigated.

SEPARATION OF Fe (III), Cr(III), Cu(II), Ni(II), Co(II), AND Pb(II) METAL IONS USING POLY(EUGENYL OXYACETIC ACID) AS AN ION CARRIER BY A LIQUID MEMBRANE TRANSPORT METHOD

Fe (III), Cr(III), Cu(II), Ni(II), Co(II), and Pb(II) metal ions had been separated using poly(eugenyl oxyacetic acid) as an ion carrier by bulk liquid membrane transport method. The effect of pH, polyeugenyl oxyacetic acid ion carrier concentration, nitric acid concentration in the stripping solution, transport time, and metal concentration were optimized. The result showed that the optimum condition for transport of metal ions was at pH 4 for ion Fe(III) and at pH 5 for Cr(III), Cu(II), Ni(II), Co(II), and Pb(II) ions. The carrier volumes were optimum with concentration of 1 x 10-3 M at 7.5 mL for Cr(III), Cu (II), Ni(II), Co(II) ions and at 8.5 mL for Fe(III) and Pb(II) ions. The concentration of HNO3 in stripping phase was optimum at 2 M for Fe(III) and Cu(II) ions, 1 M for Cr(III), Ni(II) and Co(II) ions, and 0.5 M for Pb(II) ion. The optimum transport times were 36 h for Fe(III) and Co(II) ions, and 48 h for Cr(III), Cu (II), Ni(II), and Pb(II) ions. The concentration of metal ions accurately transported were 2.5 x 10-4 M for Fe(III) and Cr(III) ions, and 1 M for Cu (II), Ni(II), Co(II), and Pb(II) ions. Compared to other metal ions the transport of Fe(III) was the highest with selectivity order of Fe(III) > Cr(III) > Pb(II) > Cu(II) > Ni(II) > Co(II). At optimum condition, Fe(III) ion was transported through the membrane at 46.46%. Keywords: poly(eugenyl oxyacetic acid), transport, liquid membrane, Fe (III), Cr(III), Cu(II), Ni(II), Co(II), and Pb(II) ions

Selective Extraction and Bulk Liquid Membrane Transport of Cu(II) from Aqueous Nitrate Solution in the Presence of Zn(II), Ni(II) and Mn(II) Cations Using Benzoyl Acetone

The competitive metal ion extraction and transport of Cu(II), Ni(II), Zn(II) and Mn(II) with benzoyl acetone and EDTA was studied. In the experiments the ligand was dissolved in chloroform and the pH and time of extraction or transport were varied. Also the rate of shaking and ligand concentration on the efficiency of extraction and transport was studied. The results revealed that the ligands exclusively extract Cu(II) from the mixture of the above cations.

Selective and efficient tripodal receptors for competitive solvent extraction and bulk liquid membrane transport of Hg 2+

A series of tripodal receptors that are different from each other in their end groups were synthesized. The extraction ability and the transport rate of these receptors were evaluated for transition metal ions (Fe 3+, Ni 2+, Cu 2+, Zn 2+ and Hg 2+). The receptor bearing pyridyl nitrogens extracted Hg 2+ from a buffered aqueous medium containing a mixture of metal ions and transported it into an organic phase with a complete selectivity over the other metal ions. This receptor was effectively used for transporting Hg 2+ from aqueous buffered source phase to aqueous receiving phase through a chloroform membrane.

Competitive bulk liquid membrane transport and solvent extraction of some metal ions using RC(S)NHP(X)(OiPr)2 (X = O, S) as ionophores. Formation of the polynuclear complex of [Ag(NC–NP(S)(OiPr)2)

Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using a series of N-(thio)phosphorylated (thio)amide and thiourea ligands as the ionophore present in the organic phase. The source phase contained equimolar concentrations of Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II) with the source and receiving phases being buffered at a number of different pHs. Solvent extraction properties of the ligands towards the same metal cations under the same experimental conditions as for the transport were also studied. All ligands demonstrated 100% extraction of Ag(I). Reaction of AgNO(3) with the potassium salt of the N-thiophosphorylated thiourea NH(2)C(S)NHP(S)(OiPr)(2) gave a new supramolecular Ag(I) complex, [AgZ](n) (Z = {N[triple bond]C-NP(S)(OiPr)(2)}(-)) that contains both tri- and tetracoordinated Ag(I). The novel polynuclear Ag(I) complex [AgZ](n) described and structurally characterized by single crystal X-ray diffraction has no precedent.

Competitive bulk liquid membrane transport of some metal ions using RC(S)NHP(S)(OiPr)2 as ionophores. Unusual supramolecular “honeycomb” aggregate of the polynuclear copper(I) complex of H2NC(S)NHP(S)(OiPr)2

Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using a series of N-(thio)phosphorylated (thio)amide and thiourea ligands as ionophores in the organic phase. The source phase contained equimolar concentrations of Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II) with the source and receiving phases being buffered at different pH. Good transport properties were observed for Ag(I) in the case of (13). The best extraction properties have been shown by (3)L(1), (3)L(8), (2)L(7), (3)L(9) and (3)L(11) which contain an unsubstituted nitrogen atom at the C[double bond, length as m-dash]S groups ((3)L(1) and (3)L(9)), or a third nitrogen atom, capable of participating in additional coordination ((3)L(8), (2)L(7) and (3)L(11)). Reaction of Cu(NO(3))(2).6H(2)O with the potassium salt of the N-thiophosphorylated thiourea NH(2)C(S)NHP(S)(OiPr)(2) formed a new supramolecular Cu(I) complex, [{Cu(6)((2)L(1))(6)}{Cu(3)((2)L(1))(3)}.4Me(2)CO] that contains both trinuclear and hexanuclear forms in its solid state structure, and in solution.

Bulk Liquid Membrane Transport of Some Main Group Metal Ions (Na+, K+, Ca2+, Mg2+) Facilitated by Non-Cyclic Synthetic Ionophores Composed of Furan - Units

Article Bulk Liquid Membrane Transport of Some Main Group Metal Ions (Na+, K+, Ca2+, Mg2+) Facilitated by Non-Cyclic Synthetic Ionophores Composed of Furan - Units was published on October 1, 2008 in the journal Main Group Metal Chemistry (volume 31, issue 5).

Extraction & Bulk Liquid Membrane Transport Studies of Biologically Important Metal Ions (Li+, Na+ and K+) by Synthetic Ionophores

Extraction & Bulk Liquid Membrane Transport Studies of Biologically Important Metal Ions (Li+, Na+ and K+) by Synthetic Ionophores