Ion Exchange Resin Research Articles

Bridged EGFET Design for the Rapid Screening of Sorbents as Sensitisers in Water-Pollution Sensors.

We further simplify the most 'user-friendly' potentiometric sensor for waterborne analytes, the 'extended-gate field effect transistor' (EGFET). This is accomplished using a 'bridge' design, that links two separate water pools, a 'control gate' (CG) pool and a 'floating gate' (FG) pool, by a bridge filled with agar-agar hydrogel. We show electric communication between electrodes in the pools across the gel bridge to the gate of an LND150 FET. When loading the gel bridge with a sorbent that is known to act as a sensitiser for Cu2+ water pollution, namely, the ion exchanging zeolite 'clinoptilolite', the bridged EGFET acts as a potentiometric sensor to waterborne Cu2+. We then introduce novel sensitisers into the gel bridge, the commercially available resins PurometTM MTS9140 and MTS9200, which are sorbents for the extraction of mercury (Hg2+) pollution from water. We find a response of the bridged EGFET to Hg2+ water pollution, setting a template for the rapid screening of ion exchange resins that are readily available for a wide range of harmful (or precious) metal ions. We fit the potentiometric sensor response vs. pollutant concentration characteristics to the Langmuir-Freundlich (LF) model which is discussed in context with other ion-sensor characteristics.

Optimized Methods for the Production of High-Purity 203Pb Using Electroplated Thallium Targets.

203Pb is a surrogate imaging match for 212Pb. This elementally matched pair is emerging as a suitable pair for imaging and targeted radionuclide therapy in cancer care. Because of the half-life (51.9 h) and low-energy γ-rays emitted, 203Pb is suitable for the development of diagnostic radiopharmaceuticals. The aim of this work was to optimize the production and separation of high-specific-activity 203Pb using electroplated thallium targets. We further investigated the radiochemistry optimization using a suitable chelator, tetraazacyclododecane-1,4,7-triacetic acid (DO3A), and targeting vector, VMT-α-NET (lead-specific chelator conjugated to tyr3-octreotide via a polyethylene glycol linker). Methods: Targets were prepared by electroplating of natural or enriched (205Tl) thallium metal. Scanning electron microscopy was performed to determine the structure and elemental composition of electroplated targets. Targets were irradiated with 24-MeV protons with varying current and beam time to investigate target durability. 203Pb was purified from the thallium target material using an extraction resin (lead resin) column followed by a second column using a weak cation-exchange resin to elute the lead isotope as [203Pb]PbCl2 Inductively coupled plasma mass spectrometry studies were used to further characterize the separation for trace metal contaminants. Radiolabeling efficiency was also investigated for DO3A chelator and VMT-α-NET (a peptide-based targeting conjugate). Results: Electroplated targets were prepared at a high plating density of 76-114 mg/cm2 using a plating time of 5 h. A reproducible separation method was established with a final elution in HCl (400 μL, 1 M) suitable for radiolabeling. Greater than 90% recovery yields were achieved, with an average specific activity of 37.7 ± 5.4 GBq/μmol (1.1 ± 0.1 Ci/μmol). Conclusion: An efficient electroplating method was developed to prepare thallium targets suitable for cyclotron irradiation. A simple and fast separation method was developed for routine 203Pb production with high recovery yields and purity.

A sustainable hydrometallurgical strategy for recycling efficiently platinum from spent reforming petroleum catalyst.

Platinum (Pt) is one of the most precious metals with a variety of unique industrial applications, particularly in catalytic reactions, being its recovery, after use, essential. Therefore, this work proposes a simplified hydrometallurgical strategy to recover Pt efficiently from the original (no milling) spent petrochemical Pt catalyst using an economical and environmentally sustainable process. To that end, the effectiveness of a two-step workflow constituted by one microwave-assisted leaching step using a mixture of hydrochloric acid (HCl) and hydrogen peroxide (H2O2) followed by one ion-exchange purification step was developed and optimized. It was found that complete dissolution of Pt plus aluminum (Al) and iron (Fe) from the roasted original size catalyst was achieved after microwave-assisted leaching with 25% (v/v) HCl and 2% (v/v) H2O2 during 2 cycles of 60s. Furthermore, a strong anionic exchange (Purogold™ A194) resin used for subsequent selective purification of Pt from Al and Fe was capable of effective separation of the metals: Pt in the eluate presented a purity of 98.1%, while Al, in the raffinate, presented a purity of 99.8%. In summation, it can be concluded that the overall process is a potentially good addition to a more circular economy as it manages to recover high-quality Pt for being reused as well as other by-products, whilst minimizing the consume of reagents, leaching time (and, thus, energy), and environmental impacts.

Optimization of Fenton process conditions in winery wastewaters treatment followed by ion exchange process to recover iron

Fenton’s oxidation has been widely studied for treatment of winery wastewater (WW). However, the generation of iron sludges imposes a significant drawback for this treatment process. Consequently, an integrated methodology was tested involving the application of ion exchange resins that recover dissolved iron without sludge production in Fenton’s Process. The aim of this study is optimizing Fenton oxidation for the abatement of COD in WW. Using a methodology design of experiments (DOE), Fenton process was able to remove up to 57% of chemical oxygen demand (COD) when pH 3, reaction time 1 h, [H2O2] = 0.15 molL−1 and [H2O2]/[Fe2+] = 15 were applied. A cationic ion-exchange resin, Dowex Marathon C, was able to recover iron present in the effluent after the oxidation process. Continuous and discontinuous trials were conducted in this scope for the synthetic solution and the real effluent after Fenton. The innovative methodology of using IE to circumvent Fenton's peroxidation limitation will surely lead to a widespread application of IE in the treatment of industrial effluents.

Poly(arylene alkylene)-Based Ion-Exchange Polymers for Enhancing Capacitive Desalination Capacity and Electrode Stability

Poly(arylene alkylene)-Based Ion-Exchange Polymers for Enhancing Capacitive Desalination Capacity and Electrode Stability

Adsorption of Niobium and Tantalum Contained in a Tin Slag Leachate by Ion Exchange Resins: Equilibrium Isotherms, Kinetic and Thermodynamic Studies

Adsorption of Niobium and Tantalum Contained in a Tin Slag Leachate by Ion Exchange Resins: Equilibrium Isotherms, Kinetic and Thermodynamic Studies

Coordination-Assisted Construction of Ultra-Fine Metal Nanoparticle Composites for Stable Sodium-Ion Battery Anodes.

Ultra-fine nanoparticles (uf-NPs) embedded in hierarchical porous carbon (HPC) have been proven to possess intriguing properties for various energy storage applications, but effective synthetic control is still lacking. Herein, we present an efficient coordination anchor activation (CAA) strategy for the scalable synthesis and elaborate control of a series of uf-NPs embedded in HPC (Sb@HPC and FeSb2@HPC as examples), which is achieved by taking advantage of the coordination capability of industrial ionic exchange resins. The in situ coordination-anchored uf-NPs and the tailored hierarchical porous HPC enables superior rate capability (533.1 mA h g-1 at 3.30 A g-1 for Sb@HPC, 276.0 mA h g-1 at 5.37 A g-1 for FeSb2@HPC), enhanced cycling stability, and high reversible areal capacity (5.02 mA h cm-2). Our study demonstrates a potentially scalable uf-NP synthesis strategy with industrial raw materials that can be applied to a large variety of energy materials.

Anion-Exchange Membrane “Polikon A” Based on Polyester Fiber Fabric (Functionalized by Low-Temperature High-Frequency Plasma) with Oxidized Metal Nanoparticles

An experimental laboratory set of samples of composite heterogeneous anion-exchange membranes was obtained by us for the development of our original method of polycondensation filling. Anion-exchange membranes were prepared on plasma-treated and non-plasma-treated polyester fiber fabrics. The fabric was treated with low-temperature argon plasma at a power of 400 W for 10 min at a pressure of 5 × 10−5 mbar. On the surface and bulk of the polyester fiber, a polyfunctional anionite of mixed basicity was synthesized and formed. The anion-exchange membrane contained secondary and tertiary amino groups and quaternary ammonium groups, which were obtained from polyethylene polyamines and epichlorohydrins. At the stage of the chemical synthesis of the anion matrix, oxidized nanoparticles (~1.5 wt.%) of silicon, nickel, and iron were added to the monomerization composition. The use of ion-plasma processing of fibers in combination with the introduction of oxidized nanoparticles at the synthesis stage makes it possible to influence the speed and depth of the synthesis and curing processes; this changes the formation of the surface morphology and the internal structure of the ion-exchange polymer matrix, as well as the hydrophobic/hydrophilic balance and—as a result—the different operational characteristics of anion-exchange membranes.

Study on the possibility of synthesizing oxygenates based on light pyrolysis resin using a modified ion exchange resin

Dialkyl ethers present potential additives to motor fuels. The study considers the possibility of obtaining oxygenates from light pyrolysis resin. The interaction of 75–90 °C fraction from light pyrolysis resin (LPR), having high content of high molecular weight unsaturated hydrocarbons, compared to other lighter fractions of LPR with a significant content of saturated hydrocarbons, and ethanol at different reagent ratios in the presence of a catalyst, Purolite CT-151 ion-exchange resin (sulfonated copolymer of styrene and divinylbenzene) modified with Na+, K+, Cu2+, Ca2+, Co2+, Ni2+ ions, is analyzed. The iodine value is chosen as the key parameter reflecting the content of unsaturated structures. The greatest decrease in the iodine value is observed for the ion exchange resin modified with cobalt ions, which is further used as the etherification catalyst. At 75–90 °C fraction:ethanol ratio of 0.5:1.5 and 60 °C, the yield of oxygenates reached 4.9% by weight.

Liquid foams with a lifetime of several days co-stabilized by monodisperse protein nanoparticles and mechanically stable starch nanocrystals

Liquid foams stabilized by protein nanoparticles generally have a lifetime less than several hours because of poor interface and unavoidable coalescence, which strictly limits their applications in, e.g., coffee toppings and milk shakes. In this study, stable foams with a lifetime of several days were prepared by protein nanoparticle-starch nanocrystal (SNC) complexes. The nanoparticles of rice proteins (RPs) or rice bran proteins (RBPs) were prepared by neutralization of their alkaline solutions by cationic exchange resins (CERs) that displace Na+ by releasing H+, leading to the formation of monodisperse, 20-nm nanoparticles facilitating diffusion to the water-air interface. The complexes were assembled by simply mixing proteins with SNCs, affording the formation of quite dispersed network structures (RP@SNCs or RBP@SNCs). During whipping, the protein nanoparticles performed as the diffusion initiators from the continuous phase to the biphasic interface, whereas the SNCs stabilized the interface and functioned as the spacers preventing the approaching of adjacent bubbles in the continuous phase. Moreover, RPs and RBPs had different affinities to SNCs, resulting in foams of varied stabilities. Our study represented a compelling example of structuring stable foams taking joint advantages of diffusion behaviors of protein nanoparticles and biphasic stabilization of SNCs.

Ammonium nitrogen (NH4+-N) recovery from synthetic wastewater using biosolids-derived biochar

The nutrient removal in the wastewater treatment plant is a critical step before the treated water is either recycled or discharged into natural water bodies. The current work provides a low-cost and environmentally sustainable nitrogen recovery approach from wastewater using biosolids-derived biochar. The biochar, produced from the pyrolysis of biosolids, was tested for NH4+-N adsorption from a synthetic wastewater sample via a batch adsorption experiment and compared with biomass-derived biochar, cation exchange resin, zeolite, and activated carbon. The adsorption capacity of biochar produced at 500 °C was around 1.8 mg g−1 for an initial NH4+-N concentration of 50 mg L−1, which was half of the cation exchange resin and zeolite given the presence of sulfonate (-SO3H) and -OH groups on their surface to exchange H+ ion with NH4+-N ion. The external surface layer and intra-particle diffusion were the rate-controlling steps of the adsorption process, as reflected in the kinetic modelling results, where a pseudo first-order model could best describe the evolution of adsorption. The presence of active sites with varied affinities towards NH4+-N adsorption on the heterogeneous surface of the adsorbent and the occurrence of multilayer adsorption were implied by the acceptable fitting of isotherm experimental data to Freundlich and Temkin models, respectively. Biosolids-derived biochar may be an attractive adsorbent for ammonium recovery from wastewater in a circular economy concept.

Synthesis of a Cation-Exchange Resin by Inverse Suspension Polymerization for Lactoferrin Extraction from Whey.

Lactoferrin (LF), the main iron-binding protein of milk, has important nutritional, biological, and pharmaceutical properties. It is an essential nutritional component of newborn diets and also for adult health. Small amounts of lactoferrin can be found in whey, a nutritionally and biologically useful byproduct of the dairy industry. Although the amount of lactoferrin in whey is less than that in other sources like milk and bovine colostrum, the extraction of LF from this underused source has many economic and environmental benefits. The most common technique for the isolation of LF from dairy products is the use of cation-exchange resins. Here, we present the synthesis of a strong cation-exchange resin for the extraction of high-purity lactoferrin from whey. This resin was synthesized by inverse suspension copolymerization of aqueous solutions of sodium 2-acrylamido-2-methyl-1-propanesulfonate and N,N-methylenebisacrylamide in corn oil. The adsorption efficiency of this resin showed selective extraction of lactoferrin from four different whey sources. The adsorption efficiency of lactoferrin from these whey samples ranged from 93.8 to 97.4%.

Determination of mass-dependent chromium isotopic compositions in geological samples by double spike-total evaporation-thermal ionization mass spectrometry (DS-TE-TIMS)

BackgroundChromium isotopes have been used to trace geochemical and cosmochemical processes in the past. However, the presence of multivalent Cr species has made it difficult to isolate Cr from geological samples, particularly for samples with a low Cr mass fraction. ResultsHere, a simple three-step ion exchange chromatography procedure is presented to separate Cr from various sample matrices, ranging from ultramafic to felsic rocks. Throughout each of the column chromatography step, 1 mL of cation exchange resin AG50W-X8 (200–400 mesh) was used as the stationary phase and oxalic acid as a chelating agent, was used in addition to the inorganic acids. This method yielded high recoveries of Cr [93 ± 8% (2SD, N = 7)] regardless of the lithology. The total procedural blank of Cr was <0.5 ng. We also developed a double spike-total evaporation-thermal ionization mass spectrometry (DS-TE-TIMS) technique that significantly reduced sample consumption to ∼20 ng of Cr per each measurement of mass-dependent 53Cr/52Cr. SignificanceThis study achieved a 2SD external precision of 0.02‰ for the analysis of NIST NBS3112a and of 0.01–0.07‰ for the geological samples. This study enabled high-precision Cr isotope analysis in geological samples with various matrix and Cr compositions using relatively small sample volumes.

TITANOMAGNETITE CONCENTRATE PROCESSING BY SORPTION CONVERSION

A hydrometallurgical technology for processing titanomagnetite concentrate has been proposed and justified. It includes the decomposition of the concentrate in low-concentration sulfur-acidic solution in the presence of sulfonic cation exchanger in H+ form with the transfer of the main part of the metals of the titanomagnetite concentrate into the sorbent and obtaining a residue enriched with ilmenite, desorption of metals from the saturated sulfonic cation exchanger with a 5 M sodium chloride solution, fractional hydrolytic precipitation and separation of titanium hydroxide, vanadium-enriched iron hydroxide, pure hydroxide iron and mixtures of iron and manganese hydroxides, regeneration of sulfonic cation exchange resin. The optimal parameters for carrying out individual processes have been determined. The technology practically does not consume sulfuric acid and does not generate liquid waste.

Gas-Phase Conversion of Cation-Exchange Resin KU-2×8-M (M = Cs, Ni, Cu, Fe, Nd, U) in a Nitrating Atmosphere

A new approach to the destructive processing of the cation-exchange resin KU-2×8-M (M = Cs, Ni, Cu, Fe, Nd, U) based on its gas-phase treatment in a nitrating atmosphere with subsequent chemical treatment of the conversion products is considered. It is shown that exposure of KU-2×8-M samples (M = Cs, Ni, Cu, Fe, Nd, U) in an HNO3(vapour)-air atmosphere at temperatures of 403-443 K for 8 and 24 h followed by dissolution conversion products in 0.5 mol∙L-1 NaOH and ozonation of the resulting solutions allows e cient utilization of the KU-2×8-M resin (M = Cs, Ni, Cu, Fe, Nd, U).

Two-Stage Conversion of Used Cooking Oil to Biodiesel Using Ion Exchange Resins as Catalysts

This study focuses on the development of a novel two-stage (esterification–transesterification) synthesis of biodiesel from used cooking oil (UCO) using ion exchange resins as catalysts. Esterification of the UCO has been conducted using various types of ion exchange resin catalysts. Purolite D5081, a hyper cross-linked resin, showed the best catalytic performance among all the catalysts investigated, with 92% of free fatty acid (FFA) conversion. The transesterification of pre-treated used cooking oil (P-UCO) was carried out sequentially using several acidic and basic ion exchange resin catalysts. In the screening process, the Diaion PA306s catalyst showed the best catalytic performance and was selected for the optimisation study. A triglyceride conversion of ca. 75% was recorded at the optimum reaction conditions (9% (w/w) catalyst loading, 328 K reaction temperature, 18:1 methanol to P-UCO feed mole ratio, and 350 rpm stirring speed). Furthermore, the reusability study of the Diaion PA306s catalyst gave a similar triglyceride conversion after a couple of cycles without losing its catalytic activity. A dry purification technique was found to give the lowest percentage of glycerides and glycerine content and, therefore, was chosen as the best biodiesel purification route.

Sequestration of Toxic Metal Ions from Industrial Effluent Using the Novel Chelating Resin Tamarind Triazine Amino Propanoic Acid (TTAPA)

Due to higher levels of industrial activity, the concentrations of toxic substances in natural water bodies are increasing. One of the most dangerous groups of toxic compounds is heavy metals, with even trace amounts of most heavy metals being harmful to aquatic life. This is why purifying water has become an urgent priority. In this context, ion-exchange resins have become more widely used in water treatment processes. However, to reduce the costs and improve the sustainability of this strategy, natural resins are favored over synthetic versions. Therefore, in the present study, a natural tamarind-based chelating resin was developed. The tamarind triazine amino propanoic acid (TTAPA) resin was synthesized and characterized using Fourier-transform infrared spectroscopy, thermogravimetry analysis, scanning electron microscopy, elemental analysis, and physicochemical analysis of the moisture content, total ion-exchange capacity, bulk volume, bulk density, and percentage nitrogen content. The biological oxygen demand and chemical oxygen demand of the industrial effluent before and after treatment were also analyzed. The batch analysis was used to determine the distribution coefficient and percentage removal of the metal ions Fe(II), Zn(II), Pb(II), Cu(II), and Cd(II). The removal efficiency of the prepared TTAPA resin was highest for Fe(II), followed by Cu(II), Zn(II), Pb(II), and Cd(II) in order. The chelating ion-exchange resin also had a metal ion recovery of more than 95%, thus demonstrating great promise for the sequestration of heavy metal ions from industrial wastewater. The proposed TTAPA resin is biodegradable, non-toxic, cost-effective, reproducible, and eco-friendly.

Application of Hydrosol to Aerosol Based Metrology to Predict Wafer Defects from Process Chemical Contamination

A method for continuous measurement of particle and particle precursor material in high purity liquids using aerosolization and condensation particle courting (A+CPC) is presented. A process for correlating wafter defects with the concentration values measured using A+CPC using Sequential Spin Coating + Surface Enhanced Particle Sizing (SSC + SEPS) is described. The method was applied to monitor the rinsate of an ion exchange resin following the SEMI C93 guide. The results showed correlation between the methods and the concentration values were used to calculate a deposition factor (liquid concentration/surface concentration) on the order of 1E5 (#/ml)/(#/cm2).

Study of the Thermochemical Effect on the Transport and Structural Characteristics of Heterogeneous Ion-Exchange Membranes by Combining the Cell Model and the Fine-Porous Membrane Model.

For the first time, based on the joint application of the fine-porous and cell models, a theoretical analysis of the changing transport and structural characteristics of heterogeneous polymeric ion-exchange membranes (IEMs) MK-40, MA-40, and MA-41 after exposure to elevated temperatures in water and aggressive media (H2SO4 and NaOH solutions), as well as after long-term processing in electrodialyzers of various types, was carried out. The studied membranes are composites of ion-exchange polymers with polyethylene and nylon reinforcing mesh. The external influences provoke the aging of IEMs and the deterioration of their characteristics. The transport properties of IEMs are quantitatively described using five physicochemical parameters: counterion diffusion and equilibrium distribution coefficients in the membrane, characteristic exchange capacity, which depends on the microporosity of ion-exchanger particles, and macroscopic porosity at a known exchange capacity of IEMs. Calculations of the physicochemical parameters of the membranes were performed according to a specially developed fitting technique using the experimental concentration dependences of integral diffusion permeability and specific electrical conductivity, and their model analogs. This made it possible to identify and evaluate changes in the membrane micro- and macrostructure and examine the process of artificial aging of the IEM polymer material due to the abovementioned external impacts.

Adsorption of Gold from Copper–Tartrate–ThiosulfateSolutions with Ion-Exchange Resins

The adsorption behavior of gold from copper–tartrate–thiosulfate solutions with ion-exchange resins was studied in this paper. Experimental parameters include resin dosage, pH, temperature, copper, tartrate, and thiosulfate concentration. A moderate increase in resin dosage, pH, temperature, and tartrate concentration is beneficial for gold adsorption, but an excessive tartrate concentration or higher temperature depresses the adsorption process. Increasing copper and thiosulfate concentrations may competitively occupy the active sites on the resin surface, leading to a reduction in the gold adsorption capacity. The XPS and FT-IR analyses indicate that copper and gold on the resin after adsorption mainly exist in the form of Cu+ and Au+, and sulfur mainly exists in the form of SO42− and S2O32−. This implies that the use of resin for gold recovery from thiosulfate leachate may face critical challenges because there is inevitably a higher content of copper and thiosulfate.