Chelating Resin Research Articles

Removal of Iron(III) and Aluminum Ions from Phosphoric Acid–Nitric Acid Solutions by S957 Chelation Resin: Kinetics, Dynamic Adsorption, and Elution

Removal of iron (III) and aluminum ions from phosphoric acid-nitric acid (PA-NA) solutions including their batch adsorption kinetics on sulfonic/monophosphonic acid chelation resin (S957) and the dynamic adsorption-elution process at the different operating parameters is studied. The results reveal that Fe(III) ion and Al(III) ion in PA-NA solutions on S957 resin present the slow batch adsorption rate. Their adsorption equilibriums are reached at 60 min and 40 min contact time, respectively. The dynamic adsorption process of Fe(III) ion and Al(III) ion is dependent on the feed flow rate through the fixed bed column, and at the 0.5 mLmin-1 flow rate, Fe(III) ion and Al(III) ion can be greatly removed from PA-NA solutions. In the dynamic elution process, the flow rate shows little effect on the elution process of Fe(III) and Al(III) ions. The better regeneration solution for the dynamic elution process is HCl solution, and the optimized concentration of HCl solution is 8 mol•L-1.

Superhigh adsorption of nickel from electroplating wastewater by raw and calcined electroplating sludge waste

Abstract Both the raw electroplating sludge (RES) waste and the calcined electroplating sludge (CES) were utilized to adsorb nickel from the real electroplating wastewater. The CES was obtained via calcination treatment at 500 °C, and the CES and RES were characterized by X-ray fluorescence (XRF), Fourier transform infrared spectrometer (FT-IR), X-ray powder diffraction (XRD). Adsorption isotherm results showed that the maximum adsorption capacities of Ni2+ on the CES and RES were 163.6 and 210.9 mg/g according to the Langmuir fitting, respectively. In the real nickel-containing wastewater treatment, the RES exhibited much higher adsorption capacity for Ni2+ than commonly used adsorbents including coal-based activated carbon (CAC), strong acid cation-exchange resin (D001), weak acid cation-exchange resin (D113) and amino carboxylic acid chelating resin (D463). The adsorption mechanisms of Ni2+ on the RES and CES mainly included ion exchange and surface complexation. The large amount of Ca2+ in the adsorbents played an important role in the adsorption of Ni2+ via cation exchange, and the hydroxyl and carboxyl groups on the adsorbent were also responsible for Ni2+ adsorption. Therefore, the electroplating sludge waste is an efficient adsorbent for Ni2+ removal from high concentrations of nickel-containing electroplating wastewater. This study provides a new method for the utilization of electroplating sludge as efficient adsorbents before being treated as hazardous waste, showing the feasible concept of disposal waste with waste.

Two-Step Preparation of an Amidoxime-Functionalized Chelating Resin for Removal of Heavy Metal Ions from Aqueous Solution

A novel amidoxime-functionalized chelating resin (PAO-g-PS) was prepared through a two-step method. First, poly (acrylonitrile) was grafted onto chloromethylated polystyrene beads via surface-initi...

Precise analysis of the concentrations and isotopic compositions of molybdenum and tungsten in geochemical reference materials

Molybdenum (Mo) is a redox-sensitive element and its concentrations and stable isotope compositions are widely used as a redox proxy in paleoceanography. Tungsten (W) is an emerging new isotope proxy, which has potential as a tracer for hydrothermal and early diagenetic processes. We present a new method for the precise and accurate analysis of Mo and W concentrations and isotope compositions from one single sample aliquot, thus saving mass of a sample and making the results directly comparable without concerns related to analytical or natural sample heterogeneity. After acid digestion, Mo and W are separated from the sample matrix using chelating resin NOBIAS Chelate-PA1 and anion exchange resin AG1 X8. Matrix removal is highly efficient: the remaining percentage is 10−2 to 10−5% with respect to the initial weight. Subsequently, samples are measured for Mo and W concentrations and isotope compositions using multi-collector inductivity coupled plasma mass spectrometry (MC-ICP-MS). For mass bias correction and determination of concentrations, we use standard-sample bracketing and in addition an external correction method employing ruthenium (Ru) for Mo and rhenium (Re) for W. This double correction approach results in an external reproducibility of or below 0.10‰ (2SD) for δ98Mo and 0.05‰ for δ186W based on ICP standard solutions (NIST SRM 3134 lot No. 130418 for Mo and NIST SRM 3163 lot No. 080331 for W). We present data for Mo and W in 12 geological reference materials including igneous rocks, sedimentary rocks, marine sediments, and manganese nodules. For Mo our method reproduces published values for the geological standard materials within analytical error of published values. For W, although published data do not always agree for a given geological standard material, our data agree within error with more recent data. We interpret a cause of the deviations is due to unknown effects of a desolvating nebulizer for MC-ICP-MS.

Recovery of metals by ion exchange process using chelating resin and sodium dithionite

Chelating ion exchange resins can be used to recover metals from nickel laterite leach solution. The main problem is the high presence of iron. In pH above 2.00, iron precipitates and there is co-precipitation of copper and cobalt, which decreases recovery process efficiency. To solve this problem, a conversion of Fe(III) to Fe(II) can be the solution, where Fe(II) will precipitate just at pH 5.00. This reducing process can also increase metals recovery, where ferrous iron occupies less active sites on the resin than ferric iron. However, studies do not evaluate what happens to the resin under this situation. This work aimed to study the copper, nickel and cobalt recovery using chelating ion exchange resin Lewatit TP 207 and reducing process using sodium dithionite 1 mol.L−1. Sodium dithionite was used to convert Fe(III) to Fe(II). The effect of reducing agent on the resin was studied. Three different solutions where prepared to simulate the real nickel laterite leach solution. Batch experiments were performed to study the effect of pH to recover metals and to compare the results with and without the reducing agent. Results showed that metals adsorption increased when the ferric iron was converted to ferrous iron by reducing process. Chelating resin adsorbed more copper and also was selective for this metal at pH 2.50. Nickel and cobalt adsorption were higher at pH 3.50, but the resin was not selective for these metals under this pH. The order of selectivity of chelating resin changed when pH increased.

Recovering rare earth elements from phosphogypsum using a resin-in-leach process: Selection of resin, leaching agent, and eluent

Phosphogypsum (PG) is an attractive secondary raw material for rare earth elements (REEs) because it is abundant and contains significant amounts of REEs. Herein, the resin-in-leach (RIL) process for REE recovery from PG was studied, and the factors affecting the yield and selectivity of conventional leaching and RIL are discussed based on the batch equilibrium data obtained using four different lixiviants, H2SO4, HCl, H3PO4, and NaCl. It was found that the chelating resin enabled the use of a low H2SO4 concentration (1 g/L) in the RIL process. The REE recovery yield and purity in the single-stage RIL process were higher when the chelating resin was used than when strong acid resins were used. The difference was significant in the multistage cross-current RIL process, where a loading of 19.2 g(REE)/kg(resin) and up to 20% purity were obtained with the chelating resin (vs. 3% in strong acid resin) after four stages. It is concluded that neither the breaking of the PG structure, nor the adsorption of calcium by the resin is necessary to enhance REE recovery. Considering the available literature and patents, this is a promising finding. REEs can be eluted from strong cation exchangers using a saturated sodium chloride solution, while EDTA or concentrated hydrochloric acid is required in the case of a chelating resin. However, Ca and REE can be further separated during elution of the chelating resin.

Stereoselective Reducing Complexes Supported in Solid Phase: Preparation and Reactivity Study

AbstractTwelve new chiral chelating resins have been prepared using solid phase organic synthesis with the Merrifield and Wang resins and the bidentate amine 1,2‐ethylenediamine, followed by the coupling of asymmetric ketones such as 1‐phenyletanone, 4‐methyl‐2‐pentanone 4‐nitroacetophenone and 4‐methoxyacetophenone to form prochiral imines. The enantioselective reduction with borane and (R)‐(+)‐2‐Methyl‐CBS‐oxazaborolidine leads to the chiral resins with yields greater than 86%. We used these chiral resins to prepare 24 reducing complexes with alkali tetrahydroborates in a very simple way giving yields greater than 87%. Finally, we achieved a preliminary enantioselective reduction of acetophenone employing the Merrifield's chiral chelating resins obtaining the corresponding S alcohol in a 70:30 ratio with the R analog alcohol.

Synthesis and Applications of Polymer Chelating Resins Containing Schiff Base

In this article, a series of Schiff-base compounds is prepared by consending aromatic dialdehydes and diamines in the presence of p-toluenesulfonic acid as catalyst. The prepared Schiff bases are characterized by CHNS/O, NMR and FTIR techniques. Moreover, analytical applications of Schiff bases as chelating agent was evaluated by loading (20 %) of compounds (B and C) the urethanic foams. Furthermore, chelating resins type P1 (B) and P2 (C) are also prepared by loading the Schiff base into polymer backbones. Moreover, the batch process is used to study the ability of these resins in recovering metals ions, such as (Mg2+, Pb2+, Cu2+, Cr3+, Ni2+, Co2+, Cd2+ and Ca2+). The study is performed by considering the contact time and pH value. Finally, the polymer’s maximum loading capacity is in the following sequence: P1 (B) Co2+ > Cr3+ > Mg2+ > Ni2+ > Cd2+ > Ca2+ > Pb2+ > Cu2+; P2 (C) Mg2+ > Cd2+ > Ca2+ > Co2+ > Pb2+ > Cu2+ > Cr3+.

Rapid determination of trace cadmium in drinking water using laser-induced breakdown spectroscopy coupled with chelating resin enrichment

The determination of heavy metals in drinking water is of great importance, but it is hard to realize rapid and in-situ measurement. Laser-induced breakdown spectroscopy is an effective method for both solid and liquid sample analysis with advantages of fast and micro-destructive. However, the concentrations of heavy metals in drinking water is too low to be directly detected using LIBS. In this study, we enhanced the sensitivity of LIBS by coupling with chelating resin, which is usually used for water purification. The resin provided a rapid enrichment of the heavy metal, so the limits of detection of common LIBS system was much enhanced. Using Cadmium as the representative heavy metal, PLSR model for predicting Cd were built based on the spectral intensity (Cd 214.4 nm) with concentrations from 0 to 100 µg/L, and resulted in correlation coefficient of 0.94433 and RMSE of 7.1517 µg/L. The LoD was 3.6 µg/L. Furthermore, the volume, resin mass, adsorption time, and LIBS system parameters were optimized for practical applications. We also demonstrated that the resin can be recycled without loss in sensing ability. The combination of chelating resin with LIBS provides inexpensive, rapid, and sensitive detection method of trace heavy metal contaminants in drinking water.

Removal of Fe3+ and Al3+ ions from phosphoric acid–nitric acid solutions with chelating resins

Fe3+ and Al3+ ions existed in phosphoric acid–nitric acid solutions are very troublesome for the neutralization process of nitrophosphate (NP) fertilizer. This paper studied the performances of three chelating resins (S957, S950 and S930) on the removal of Fe3+ and Al3+ ions from phosphoric acid–nitric acid solutions, and one strong acid cation resin (001×7) was also studied for comparison. The batch adsorption equilibrium of Fe3+ ion and Al3+ ion on four resins and the effects of phosphoric acid and nitric acid concentrations on the separation characteristics of four resins were firstly investigated. After that, the dynamic adsorption and elution processes through the fixed bed column were carried out. The batch adsorption results reveal that S957 and 001×7 resins present the higher adsorption ability to Fe3+ ion and Al3+ ion in pure water. But in phosphoric acid–nitric acid solutions, the adsorption ability of S957 and S950 resins is better for the removal of Fe3+ ion and Al3+ ion, whereas 001×7 and S930 resins present very low or even no adsorption ability. The dynamic adsorption and elution processes show that S957 resin is more suitable for the further dynamic operation in view of the recyclability of separation process, while S950 resin expresses poor regeneration performance. Moreover, the coexistent Ca2+ and Mg2+ ions in phosphoric acid–nitric acid solutions have little influence on the removal of Fe3+ and Al3+ ions through the fixed bed S957 resin column. All results demonstrate that S957 resin is capable of removing the Fe3+ and Al3+ ions from phosphoric acid–nitric acid solutions.

Speciation of Trivalent/Hexavalent Chromium in Fly-ash Extracts by Solid-phase Extraction/Atomic Absorption Spectrometry Using a Chelate Resin Treated with Iron(III) Nitrate

Speciation of Trivalent/Hexavalent Chromium in Fly-ash Extracts by Solid-phase Extraction/Atomic Absorption Spectrometry Using a Chelate Resin Treated with Iron(III) Nitrate

Study on Fe (II) Type Heterogeneous Fenton Decolorized Rhodamine B Supported by Aminophosphoric Chelate Resin

The main objective of this work was to study the decolorization of the rhodamine B in aqueous solution using Fenton process. Ls-5000 chelating resin loaded Fe2+ Fenton reagent was prepared by shaking impregnation method. The effects of various factors on the treatment of rhodamine B were preliminarily investigated. The results show that the optimal process conditions for photo-assisted heterogeneous Fenton decolorized rhodamine B with Ls-5000 chelating resin loaded Fe2+ is: 0.60g Ls-5000 chelate resin loaded Fe2+ + 1.5mL H2O2 + 60W visible light power + solution pH=2. 96.21% of decolorization efficiency could be achieved after 180 minutes under the Ls-5000 chelate resin loaded Fe2+/H2O2 reaction system.

Thermal Decomposition Behavior of a Chelating Resin Immobilizing Carboxymethylated Polyethyleneimine: Possibility of Estimation of Carboxymethylation Rate.

Chelating resins immobilizing carboxymethylated polyethyleneimine (CM-PEI) with different carboxymethylation rates were prepared. The thermal decomposition behavior of CM-PEI resins was investigated using thermogravimetry-differential thermal analysis/photo ionization-quadrupole mass spectrometry (TG-DTA/PI-QMS) and ion attachment ionization-quadrupole mass spectrometry equipped with direct inlet probe (DIP/IA-QMS). The obtained results suggested that the carboxymethyl group decomposed at relatively low temperature (150 °C - 300 °C); the peak areas at m/z 45 and 59 in TG-DTA/PI-QMS and m/z 58, 70, and 72 in DIP/IA-QMS significantly increased with increasing carboxymethylation rate. These relationships should be useful for estimating the carboxymethylation rate of CM-PEI resin.

Performance of chemical chelating agent stabilization and cement solidification on heavy metals in MSWI fly ash: A comparative study

Heavy metal stabilization by chemical chelating agent and solidification by cement are technologies currently used to reduce the leaching of heavy metals in municipal solid waste incineration (MSWI) fly ash. This paper studied the physico-chemical properties of the fly ash, heavy metals content in the fly ash, and the leaching concentration of the heavy metals from fly ash. The effect of four chelating agents namely dithiocarbamate (1#), dithiocarbamic acid dipotassium salt (2#), amino dithiocarbamate chelating resin (3#) and thiourea (4#) on the stabilization and leaching of heavy metals were investigated. Different addition ratios (1%, 2% and 3% w/w) of the chelating agents, various curing time (7, 14, 28 days), and different amounts of the cement (10%, 15% and 20% w/w) were used in order to find the agent with the optimum stabilization and leaching of heavy metals as well as find the effect of combining the agent and cement. The results showed that the dithiocarbamate (1#) chelating agent had the best stabilizing performance due to the three-dimensional structure after their reaction. The addition of cement to the fly ash led to the immobilization of heavy metals due to the C-S-H gel formation. The technology of cement solidification and chelating agent stabilization was optimal from the point of economic cost and the complexity aspect.

Extraction and recovery of rare earths by chelating phenolic copolymers bearing diglycolamic acid or diglycolamide moieties

Extraction and recovery of rare earth elements (REEs) have been studied using ion-exchange and chelating process thanks to phenol copolymeric resins. The ion-exchange and chelating resins have been prepared through an alkaline polycondensation reaction of phenolic diglycolamic acid or diglycolamide derivatives with admixture of phenol, catechol or resorcinol in the presence of formaldehyde as crosslinker. The phenol copolymeric resins were fully characterized and involved in sorption experiments. The sorption experiments of rare earth elements have been investigated in different acidic conditions. Lanthanum (La), europium (Eu) and ytterbium (Yb) were chosen to represent the light, medium and heavy REEs respectively. Changes in the extraction properties of the copolymeric resins have been observed depending on the nature of chelating groups in the phenolic matrices and the extraction conditions. The obtained results indicate that the synthesized material exhibit good sorbent properties for REEs with cation uptake capacity in the range 50–100 mg/g and in some cases above 150 mg/g.

Adsorption of U(VI) and Th(IV) from simulated nuclear waste using PAMAM and DGA functionalized PAMAM dendron grafted styrene divinylbenzene chelating resins

The recovery of actinides such as U(VI) and Th(IV) from nuclear waste is a critical challenge and it requires the development of novel selective and high-capacity sequestering materials. Herein a novel chelating adsorbents are prepared by grafting poly(amido)amine (PAMAM) and diglycolamic acid (DGA) functionalized PAMAM dendron on styrene divinyl benzene (SDB) solid support. Adsorption of U(VI) and Th(IV) from simulated nuclear liquid waste (SNLW) using PAMAM–SDB and DGA–PAMAM–SDB chelating resins were carried out. Our studies have found that PAMAM–SDB and DGA–PAMAM–SDB chelating resins exhibited good adsorption selectivity for U(VI) and Th(IV) at pH 5.5 in presence of other metal ions. In addition, these chelating resins finds potential application for total decontamination of SNLW at pH 12. Hence, PAMAM–SDB and DGA–PAMAM–SDB are promising chelating resins for selective removal of U(VI) and Th(IV) and also total decontamination of aqueous radioactive waste.

Development of a method for measuring rare earth elements in the environment for future experiments with gadolinium-loaded detectors

Abstract Demand to use gadolinium (Gd) in detectors is increasing in the field of elementary particle physics, especially in neutrino measurements and dark matter searches. Large amounts of Gd are used in these experiments. To assess the impact of Gd on the environment it is becoming important to measure the baseline concentrations of Gd. Such measurement, however, is not easy due to interference by other elements. In this paper a method for measuring the concentrations of rare earth elements, including Gd, is proposed. In the method, inductively coupled plasma-mass spectrometry is utilized after collecting the dissolved elements in chelating resin. Results of the ability to detect anomalous concentrations of rare earth elements in river water samples in the Kamioka and Toyama areas are also reported.

High selective reduction of nitrate into nitrogen by novel Fe-Cu/D407 composite with excellent stability and activity

In this study, we develop a new composite material of Fe-Cu/D407 composite via using nanoscale zero-valent iron (nZVI) with copper deposited on chelating resin (D407) to remove nitrate from the water. The experimental results show that a remarkable nitrate removal and the selectivity of N2 are 99.9% and 89.7%, respectively, under the anaerobic conditions of Cu/Fe molar ratio of 1:2, pH = 3.0. Even without of inert gas and adjusting the initial pH of the solution, the removal rate of nitrate by Fe-Cu/D407 reached to 85% and the selectivity of nitrogen reached to 55%. Meanwhile, the Fe-Cu/D407 maintained preferable removal efficiency of nitrate (100% - 92%) over a wide pH range of 3–11. In addition, the removal rate of the drinking water, lake water and wastewater from the Fe-Cu/D407 is still very high and the reactivity of Fe-Cu/D407 was relatively unaffected by the presence of dissolved ions in the waters tested. Moreover, the synergetic effect of Fe, Cu and D407 in the composite Fe-Cu/D407 were well investigated for the first time according to the analyses of TPR, XPS and EIS. The catalytic mechanism and denitrification routes were also proposed.

Analysis of trace metals in water samples using NOBIAS chelate resins by HPLC and ICP-MS

The pre-concentration of major constituents is crucial to accurate and precise determination of trace metals in water samples by inductively coupled plasma mass spectrometry (ICP-MS). In this work, NOBIAS chelate resins were used in the sample concentration for both HPLC and ICP-MS detection. 4-(2-Pyridylazo) resorcinol (PAR) was selected as a precolumn chelating reagent for this research. 520 nm wavelength was used as to minimize the peak of PAR and to reduce baseline noise for HPLC analysis. The sample pre-treatment step was achieved by enrichment and Cd(II), Co(II), Cu(II), Mn(II), Ni(IV), Pb(II), and Zn(II) were detected in the bottled water and tap water samples. The results of two detection methods of ICP-MS and HPLC were compared. Results showed that by acquiring 50-time pre-concentrates of test samples using 250 mg of the Nobias-chelate PA1 chelating resin, the metal contents could be accurately detected using both ICP-MS and HPLC. And the approach of HPLC enables the quantitative detection of bottled water and tap water at different concentrations with determination coefficient (R2) greater than 0.9990. This simple and cost-effective quantitative detection approach using NOBIAS chelate resins and HPLC may widen the application of NOBIAS chelate resins for quantitative detection of more water samples.

Development of the diffusive gradients in thin films technique (DGT) for platinum (Pt), palladium (Pd), and rhodium (Rh) in natural waters

The Diffusive Gradients in Thin Films (DGT) technique was developed for the first time for the platinum group elements (PGEs) platinum (Pt), palladium (Pd), and rhodium (Rh). Different chelating resins, specific designed for the accumulation of PGEs, namely Purolite S914, S920, S985, Italmatch Chemicals IONQUEST® MPX-317 and MP-102, were compared. The method development involved several different steps: 1) selection of an appropriate diffusive gel, 2) comparison of resins for the PGEs in terms of kinetics of uptake, 3) development of an efficient elution method for the PGEs from the resin gel, 4) Determination of diffusion coefficients for the PGEs in the diffusive gel, 5) Investigation of the influence of pH, ionic strength and dissolved organic matter on the diffusion coefficients and 6) study the selectivity of the tested resins gels in terms of potential interferences on the determination by ICPMS.Pt, Pd and Rh showed a linear accumulation over time for all resins and diffusion coefficients were independent of pH. The diffusion coefficient for Pt increased with increasing ionic strength (>0.5 M NaCl), but not for Pd and Rh. The interference study showed that Sr was the most important interferent for Rh and Pd and must be removed prior to analysis. The resins Purolite S914, Purolite S920, and Italmatch Chemicals IONQUEST® MPX-317 showed the best performance in terms of detection limits and separation of interferences. Using optimized procedures, the concentrations of Pt, Pd and Rh can be quantified at pg L−1 levels in natural waters for a 14 day deployment time.