Extractant-impregnated Resin Research Articles

Study of the kinetic, equilibrium, and thermodynamic aspects of the removal and recovery of divalent lead heavy metal ions from industrial wastewaters contaminated by vesavin-enriched XAD-11600 amberlite resin

In this study, we developed a unique adsorbent known as extractant-impregnated resin (EIR) by surface impregnation of XAD-11600 amberlite resin with the Vesavin ligand. This resin demonstrated exceptional selectivity for the absorption of lead (Pb2+) ions from aqueous solutions. The ability of EIR to remove lead from polluted water was studied as a function of experimental parameters, including the kinetics, equilibrium, and thermodynamics of the adsorption process. The experimental results provided the basis for the fitting of equilibrium adsorption isotherms with the Langmuir model, and the maximum adsorption capacity of EIR for Pb(II) ions was determined to be approximately 1662 mg/g. Kinetic and thermodynamic studies were also conducted to gain insight into the behavior of the adsorption process. It was found that the rate of penetration of lead ions into the particle was the primary factor controlling the absorption process of lead on the surface of the porous adsorbent. Additionally, the studies demonstrated that the EIR can be utilized for multiple absorption and desorption cycles.

Radiochemical separation of 111In from irradiated cadmium targets by D2EHPA-St-DVB extractant impregnated resin

Radiochemical separation of 111In from irradiated cadmium targets by D2EHPA-St-DVB extractant impregnated resin

Environmentally friendly Pd(II) recovery from spent automotive catalysts using resins impregnated with a pincer-type extractant

Extractant-impregnated resins have potential for recovering platinum group metals selectively and efficiently. Herein, 1,3-bis(2-(octylthio)propan-2-yl)benzene (1), a pincer-type extractant, was impregnated in Amberlite XAD-7 resin (1-EIR), and the batch Pd(II) sorption conditions, including impregnated amount, shaking time, Pd(II) concentration, HCl concentration, and Pd(II) desorption reagents, were optimized. The maximum Pd(II) sorption capacity of 1-EIR was 49 mg g−1 after 24 h in a 700 ppm Pd(II) solution. Over 20 adsorption–desorption cycles, 1-EIR showed good reusability, with a sorption percentage (S%) of > 92%. However, not all Pd(II) was desorbed from 1-EIR. Complete Pd(II) collection was achieved by combining desorption with flaking of the Pd–extractant complex from Pd(II)-loaded 1-EIR by Soxhlet extraction, as ~ 13 mg g−1 remained after the 20th adsorption–desorption cycle by absorptiometric method. The sorption mechanism was elucidated based on the Langmuir isotherm model, thermodynamic parameters, and sorption kinetics. Pd(II) sorption by 1-EIR was spontaneous and endothermic, and the sorption kinetics followed a pseudo-second-order model. Notably, 1-EIR also exhibited high selectivity for Pd(II) from a simulated mixed metal solution and a spent automotive catalyst leachate (S% = 98% and > 99%, respectively). Thus, this extractant-impregnated system is promising for selective Pd(II) recovery from spent automotive catalysts and other secondary resources.

Column and batch sorption investigations of nickel(II) on extractant-impregnated resin.

Macroporous resin-supported reagents have been identified as potential adsorbents for removal of toxic pollutants. This article presents an experimental designed to evaluate the sorption and desorption of nickel(II) with the help of column and batch procedure using simple extractant-impregnated resin (EIR). Isonitroso-4-methyl-2-pentanone (IMP) as an extractant was impregnated on a solid support like Amberlite XAD-4 to prepare the EIR sorbent. Column experimental conditions such as pH, sample flow rate and volume, eluting solution, and interfering ions were studied to optimize the nickel(II) sorption and recovery from aqueous media. The column results suggest that the quantitative nickel(II) sorption was observed at pH 5-6, and the quantitative recovery (≥ 95%) was achieved by using 1.0 M HNO3. The high concentrations of cations and anions (except EDTA) present in the spiked binary and multi-element mixture solution show no interferences in both quantitative sorption and recovery of nickel(II), whereas the batch experiments were performed to evaluate nickel(II) sorption behavior using the linearized and non-linearized kinetic and isotherm models. By error function analysis, the Freundlich isotherm and the pseudo-first-order kinetic model were found to describe best the experimental data obtained over the studied concentration range and sorption time, respectively. The maximum sorption capacity of nickel(II) onto the EIR sorbent was found to be ~ 81 mg/g. The mean free energy (E = 10.1 kJ/mol) determined using Dubinin-Radushkevich isotherm suggests chemical nature of nickel(II) sorption on EIR. The novelty of the EIR adsorbent lies in its potential for separation and recovery of nickel(II) at trace level in water samples of different origin.

Amberlite XAD-2010 Impregnated with Chrome Azurol S for Separation and Spectrophotometric Determination of Uranium and Thorium

A new extractant-impregnated resin (EIR), chrome azurol S-impregnated on XAD-2010, is used as an adsorbent to separate and preconcentrate U(VI) and Th(IV) ions prior to their spectrophotometric determination. Various instrumental techniques such as elemental analysis, FTIR, and SEM analysis were employed for full characterization of the synthetic extractant. Optimization of the adsorption and elution conditions of U(VI) and Th(IV) ions using synthesized chrome azurol S-impregnated XAD-2010 were studied. Langmuir isotherm model has the best fitting experimental data with a maximum adsorption capacity of 23.8 mg g−1 for U(VI) and 25.4 mg g−1 for Th(IV). The adsorption process of each metal ion using synthesized chrome azurol S-impregnated XAD-2010 showed an exothermic pseudo-second-order adsorption process. High tolerance limits for several studied metal ions on chrome azurol S-impregnated XAD-2010 were observed. The optimized method was applied on an international certified samples and different rock types bearing thorium and uranium with accurate results.

A new extractant impregnated resin for separation of traces of uranium and thorium followed by their spectrophotometric determination in some geological samples

A new extractant-impregnated resin, alizarin red S -impregnated XAD-2010, is used as an adsorbent to separate and preconcentrate U(VI) and Th(IV) ions prior to their spectrophotometric determination. Various instrumental techniques such as elemental analysis, FTIR, and SEM analysis were employed for full characterization of the synthetic extractant. Optimization of the adsorption and elution conditions of U(VI) and Th(IV) ions using synthesized alizarin red S -impregnated XAD-2010 were studied. Langmuir isotherm model has the best fitting experimental data with a maximum adsorption capacity of 20.2 mg g−1 for U(VI) and 18.25 mg g−1 for Th(IV). The adsorption process of each metal ion by synthesized alizarin red S -impregnated XAD-2010 showed an exothermic pseudo-second-order adsorption process. The tolerance limits for several metal ions on alizarin red S -impregnated XAD-2010 were calculated, giving high tolerance limit. The optimized method was applied on international certified samples and different rock types bearing thorium and uranium with accurate results.

Encapsulation of Cyanex 302 with Alginate for Palladium Recovery

A new generation of extractant impregnated resin has been elaborated by encapsulation of extractants in biopolymer capsules. The extractant forms the core of the spherical particle, while the biopolymer entraps the extractant in a shell. The immobilization can reduce the loss of extractant. Cyanex 302 (bis(2,4,4‐trimethylpentyl)monothiophosphinic acid) was efficiently immobilized into alginate capsules prepared by ionotropic gelation in CaCl2 solutions. The influence of a series of parameters on microcapsule preparation was investigated. Selected materials were tested for Pd(II) recovery from HCl solutions through the study of sorption isotherms and uptake kinetics.

Extractant Immobilization in Alginate Capsules (Matrix- and Mononuclear-Type): Application to Pb(II) Sorption from HCl Solutions.

The decontamination of dilute industrial effluents is a critical challenge for decreasing the environmental impact of mining and metallurgical activities. As an alternative to conventional processes, new extractant impregnated resins (EIRs) have been synthesized by the immobilization of Cyanex 301 and Cyanex 302 in alginate capsules using two different procedures (matrix-type immobilization vs. mononuclear encapsulation). These materials have been tested for Pb(II) sorption from acidic solutions. The Langmuir equation fitted well the sorption isotherms and the maximum sorption capacities vary between 24 and 80 mg·g−1 at pH 1, depending on the type and loading of the extractant in the EIR. Uptake kinetics were controlled by the resistance to intraparticle diffusion; though both the Crank equation (intraparticle diffusion) and pseudo-second order rate equation equally fitted uptake profiles. The amount of extractant immobilized in mononuclear capsules is lower than in matrix-type beads; this leads to lower sorption capacities but slightly better mass transfer properties. The balance between the advantages and drawbacks of the different systems makes more promising matrix-type capsules. The desorption of Pb(II) is possible using 1 M HNO3 solutions: metal ions were completely desorbed. However, the probable oxidation of the extractants (conversion to oxidized forms more sensitive to pH) reduces the sorption efficiency when they are re-used.

How the conditioning and storage of samples for SEM-EDX analysis may influence the interpretation of diffusion mechanisms in the sorption of metals ions by extractant impregnated resins

BACKGROUND Modeling mass transfer steps is important for optimizing the use of sorbents such as extractant impregnated resins (EIR). However, mathematical fit of kinetic profiles requires physical characterization for validating mechanism hypotheses. SEM-EDX is a very useful tool for achieving this objective. RESULTS In this work a special attention has been focused on the simultaneous modeling of the diffusion mechanisms (using homogeneous diffusion and shrinking core models associated to resistance to film diffusion, to intraparticle diffusion and to chemical reaction rate) and the SEM-EDX analysis of the diffusion profiles for gold sorption on ionic liquid/impregnated resins (tetraalkylphosphonium IL immobilized in Amberlite XAD resins). Some discrepancies in the conclusions raised by the two approaches led to carefully investigate the effect of conditioning and storage of resins before SEM-EDX analysis. The self-diffusion of the metal ion in the EIR causes misinterpretation of diffusion profiles when inappropriate conditions are used. CONCLUSION SEM-EDX can be efficiently used for improving the understanding of diffusion mechanisms in the study of metal uptake kinetics in EIRs providing that the analysis of the samples is carried out within 24 h and the sample is freeze-dried (to limit metal-ion self-diffusion in the extractant phase). This study can obviously be extended to other sorption systems.

Amberlite XAD-1180 impregnation with Cyphos IL101 for the selective recovery of precious metals from HCl solutions

The impregnation of Amberlite XAD-1180 with Cyphos IL101 (trihexyl(tetradecyl)phosphonium chloride ionic liquid, IL) confers to the resin highly efficient extraction properties for Au(III), Pd(II), and Pt(IV) in highly concentrated HCl solutions. Extraction isotherms (fitted by the Langmuir equation) show maximum extraction capacities proportional to IL loading. Increasing the IL loading has a limiting effect for extraction kinetics, which are controlled by the resistance to intraparticle diffusion: the complete filling of the porous volume of the extractant-impregnated resin (EIR) with the IL considerably hinders mass transfer of target metal ions. The EIRs are selective for precious metals (PGMs) over base metals (BMs), and the selection of appropriate eluents (HCl, HNO3, acidic thiourea) allows recovering almost selectively the three metals in pure or highly enriched proportions.

Novel extractant impregnated resin for preconcentration and determination of uranium from environmental samples

A novel method based on impregnation of Amberlite XAD-4 with extractant isonitroso-4-methyl-2-pentanone (IMP) has been developed for U6+ extraction and determination in various samples. The prepared extractant impregnated resin (EIR) sorbent was characterized by the field emission scanning electron microscope. The sorbent was packed in a glass column and investigated for various parameters such as pH, eluent, sample and eluent flow rates to optimize sorption desorption conditions for U6+. U6+ is quantitatively determined at pH4 with flow rate 2mL/min which showed recovery of 98.9%. The sorption behaviour of U6+ by EIR was also studied using different equilibrium isotherms and kinetic models and the experimental data confirmed that it follows Freundlich isotherm and Weber-Morris pore diffusion kinetic model. The investigation of foreign ions influence on U6+ sorption showed least interference and thus, facilitated its extraction and determination in Uranmicrolite (leachate) ore tailing, synthetic mixtures and spiked water samples. The detection limit was 0.41μg/L while the limit of quantification as 1.35μg/L made the method quite accurate.

Sorption efficiency of three novel extractant-impregnated resins containing vesuvin towards Pb(II) ion: Effect of nitrate and amine functionalization of resin backbone

A macroporous polymeric resin, Amberlite XAD-1160, functionalized with −NO2(electron-acceptor) and −NH2(electron-donor) groups to prepare two new functional macroporous resins, NO2-XAD-1160 and NH2-XAD-1160 respectively, and three novel extractant-impregnated resins (EIRs) were prepared by impregnating XAD-1160, NO2-XAD-1160 and NH2-XAD-1160 with vesuvin, as an advantageous extractant. The sorption efficiencies of both VSV/NO2-XAD-1160 and VSV/NH2-XAD-1160 towards Pb(II) ion were compared with those of conventional VSV/XAD-1160 to gain insight about the effects of functional groups on the kinetics, equilibrium, thermodynamic and other sorption properties. Comparative studies showed that VSV/NO2-XAD-1160 benefits for using in full-scale treatment processes are more than those of VSV/XAD-1160 and VSV/NH2-XAD-1160.

Influence of the textural characteristics of the support on Au(III) sorption from HCl solutions using Cyphos IL101-impregnated Amberlite resins

A series of Amberlite XAD resins (acrylic ester and styrene–divinylbenzene resins) has been impregnated with Cyphos IL101 ionic liquid (IL: trihexyl(tetradecyl)phosphonium chloride) for Au(III) sorption from HCl solution. The textural characteristics (specific surface area, pore size distribution and pore volume) of the extractant impregnated resins (EIRs) have been determined in function of IL loading. The HCl concentration and the IL loading have a significant impact on Au(III) sorption efficiency: acrylic ester resins can weakly bind Au(III) contrary to styrene–divinylbenzene resins that only extract metal ions through the ion exchange of tetrachloro-anionic species with chloride ions from the IL. Uptake kinetics are strongly controlled by both the IL loading, the textural properties of the resin and, in some cases, by the pre-conditioning of the resin. Though a clear correlation exists between pore size/pore volume and apparent intraparticle diffusion coefficients, some resins showed atypical behavior (having lower relative coefficients of intraparticle diffusion than expected from the textural properties of raw resins, while their De fits better the actual textural properties of impregnated materials). Sorption efficiency increases with IL loading while uptake kinetics is slowed down. A good compromise is obtained in terms of both sorption efficiency and uptake kinetics using XAD-1180 resin impregnated with Cyphos IL101 (with IL loading not exceeding 400mgILg−1EIR).

Thorium removal from weakly acidic solutions using titan yellow-impregnated XAD-7 resin beads: kinetics, equilibrium and thermodynamic studies

To remove Th(IV) ion from acidic solutions (pH 2.5–2.7), an extractant-impregnated resin (EIR) was fabricated by impregnation of Ambelite XAD-7 resin beads with titan yellow as extractant. Various physicochemical factors such as pH, contact time, temperature, sorbent dose and initial concentration of thorium were investigated. The isotherm data was well interpreted by the Langmuir model. Kinetic experiments data showed that the sorption process could be described by Weber–Morris kinetic model. Thermodynamic studies revealed the feasibility, spontaneity and endothermic nature of sorption process. Desorption experiments showed that the EIR could be reused without significant losses of its initial capacity.

Novel Extractant Impregnated Resin for Thorium Preconcentration from Different Environmental Samples: Column and Batch Study

A developed method based upon impregnation of Isonitroso-4-methyl-2-pentanone (HIMP) as extractant on Amberlite XAD-4 for Th4+ enrichment and spectrophotometric determination in a variety of samples were reported. This Extractant Impregnated Resin (EIR) sorbent is characterized by Fourier Transforms-Infrared Spectrometer (FT-IR), Field Emission-Scanning Electron Microscope (FE-SEM), and Brunauer-Emmett-Teller (BET) analysis. The EIR packed in column was studied for various parameters to optimize sorption desorption condition for Th4+. Sorption of Th4+ from aqueous solution onto EIR was studied and equilibrium isotherms, kinetics were determined. These investigations facilitate its determination in different real samples. The developed method was validated by analyzing lake sediment standard reference material (IAEA-SL-1).

Preconcentration and determination of ultra-trace amounts of U(VI) and Th(IV) using titan yellow-impregnated Amberlite XAD-7 resin

A simple and sensitive method for the determination of ultra trace amounts of U(VI) and Th(IV) ions by spectrophotometric method after solid-phase extraction on a new extractant-impregnated resin (EIR) has been reported. The new EIR was synthesised by impregnating a weakly polar polymeric adsorbent, Amberlite XAD-7, with titan yellow (TY) as extractant. The analytical method is based on the simultaneous adsorption of analyte ions in a mini-column packed with TY/XAD-7 and performing sequential elution with 0.5% (w/v) Na2CO3 for uranium and 2.0 M HCl for thorium. The influences of the analytical parameters including pH, salting out agent and sample volume were investigated. The interference effects of foreign ions on the retention of the analyte ions were also explored. The limits of detection for U(VI) and Th(IV) were as low as 50 and 25 ng L−1, respectively. Relative standard deviations (n = 7) for U(VI) and Th(IV) were 3.1% and 2.9%, respectively. The method was successfully applied to the determination of ultra trace amounts of U(VI) and Th(IV) in different real matrices including industrial wastewater samples and environmental waters. The proposed method was validated using three certified reference materials and the results were in good agreement with the certified values.

Kinetic, equilibrium and thermodynamic studies on sorption of uranium and thorium from aqueous solutions by a selective impregnated resin containing carminic acid

In this work, the removal of uranium and thorium ions from aqueous solutions was studied by solid–liquid extraction using an advantageous extractant-impregnated resin (EIR) prepared by loading carminic acid (CA) onto Amberlite XAD-16 resin beads. Batch sorption experiments using CA/XAD-16 beads for the removal of U(VI) and Th(IV) ions were carried out as a function of several parameters, like equilibration time, metal ion concentration, etc. The equilibrium data obtained from the sorption experiments were adjusted to the Langmuir isotherm model and the calculated maximum sorption capacities in terms of monolayer sorption were in agreement with those obtained from the experiments. The experimental data on the sorption behavior of both metal ions onto the EIR beads fitted well in both Bangham and intra-particle diffusion kinetic models, indicating that the intra-particle diffusion is the rate-controlling step. The thermodynamic studies at different temperatures revealed the feasibility and the spontaneous nature of the sorption process for both uranium and thorium ions.

Bismuth(III) recovery from hydrochloric acid solutions using Amberlite XAD-7 impregnated with a tetraalkylphosphonium ionic liquid

An Ionic Liquid (IL) (Cyphos IL 101: tetradecyl(trihexyl)phosphonium chloride was immobilized on Amberlite XAD-7 for preparing extractant impregnated resins (EIRs). The IL content was varied between 59 and 586mgILg−1 EIR. The EIRs were tested for Bi(III) recovery from (0.01–8M) HCl solutions. The EIRs were very efficient at extracting Bi(III), the sorption efficiency increased with IL content in the resin, but decreased with HCl concentration. Bi(III) was extracted through an ion exchange mechanism involving the binding of its anionic chloro-complexes to IL phosphonium cation. Sorption isotherms were fitted with the Langmuir equation and they were found to be very favorable with maximum sorption capacities up to 84.3mgBig−1 EIR (in 1M HCl solution using an EIR with 401mgLig−1 EIR at 20°C). Temperature slightly influenced Bi(III) sorption capacity. Bi(III) recovery selectivity was studied in bimetallic (1M HCl) solutions, where, Cu(II) and Ni(II) were not removed but Zn(II) was partially extracted slightly affecting Bi(III) recovery. Sorption kinetics was not affected by agitation speed: the resistance to film diffusion is not the limiting step. The uptake kinetics were controlled by the resistance to intraparticle diffusion. The intraparticle diffusivity coefficients decreased with increasing IL loading but increased with temperature due to the decrease of IL viscosity (in the EIRs). Bi(III) can be easily desorbed from EIRs using either citric acid, nitric acid or sodium sulfate solutions. The EIRs could be recycled maintaining high efficiencies for sorption and desorption for at least five cycles.

Use of a selective extractant-impregnated resin for removal of Pb(II) ion from waters and wastewaters: Kinetics, equilibrium and thermodynamic study

Adsorption of Pb(II) ion by a novel extractant-impregnated resin, EIR, was studied as a function of various experimental parameters using batch adsorption experiments. The new EIR was prepared by impregnating gallocyanine (GCN) onto Amberlite XAD-16 resin beads. The EIR was characterized by nitrogen analysis and SEM micrographs. The new EIR showed excellent selectivity factor values (α) for Pb(II) adsorption respect to other metal ions. The effects of some chemical and physical variables were evaluated and the optimum conditions were found for Pb(II) removal from aqueous solutions. The equilibrium adsorption isotherm was fitted with the Langmuir adsorption model. The maximum adsorption capacity (qmax) of EIR for Pb(II) ions was found to be 367.92mgg−1. The kinetic studies showed that the intra-particle diffusion is the rate-controlling step. Also, the intra-particle diffusion coefficients, Dip values, were of the order of 10−12m2s−1. The values of enthalpy (ΔH°) were positive, which confirms the endothermic nature of adsorption process. Also, the positive entropy changes (ΔS°) were showed that the randomness increased along with the adsorption process. In addition, the obtained negative values of Gibbs free energy (ΔG°) indicated feasible and spontaneous nature of the adsorption process at different temperatures. The new adsorbent was very stable so that it can be successfully used for many consecutive cycles without significant loss in its adsorption capacity.

Adsorption behavior of metal ions on alkylhistidine extractant impregnated resins: Effect of functional groups of histidine

Two types of alkylhistidine extractants, histidine-2-ethylhexyl amide (His-EH) and N-p-tert-octylphenoxyacetyl-histidine (OP-His) were prepared. The alkylhistidine extractants were impregnated onto a methacrylate-based polymer support to investigate the adsorption selectivity for metal ions. His-EH, which has coordinating imidazole and amino groups, adsorbs Cu(II), Ni(II), Zn(II) and Co(II) at pH>5. By contrast, OP-His, which has imidazole and carboxyl groups, shows adsorption selectivity; Cu(II)>Zn(II)>Ni(II)>Co(II). A column was packed with OP-His impregnated resin to investigate the separation selectivity between Cu(II) and Co(II). Cu(II) was selectively adsorbed and was efficiently concentrated to 59 times the concentration of the feed solution.