KU-2 Cation-exchange Resin Research Articles

Towards optimized cation-exchange membranes for overlimiting current electrodialysis: Correlation between size of resin particles in membranes and mechanism of ion transport through them

Experimental heterogeneous membranes with different particle sizes of cation-exchange resin KU-2–8 (the diameter of resin particles varied from 20 to 71 μm) were manufactured under the production conditions of LLC “IE “Shchekinoazot”. It is established that at currents higher than the limiting current the main mechanisms of electrolyte ion transport are classical electrodiffusion and electroconvection. It is shown for the first time that at the same degree of membrane polarization i/ilim the fraction of electroconvection contribution increases, and the fraction of contribution of water splitting reaction products decreases with decreasing size of resin particles in membranes. The theoretical evaluation of the influence of the size of resin particles in the membrane on the internal parameters of electromembrane systems MK-40/0.01M NaCl solution has shown that the crucial role in the development of electroconvection is played not by the field effect, but by the peculiarities of electrical heterogeneity of the membrane surface.

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).

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

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

Выделение и радиохимическая очистка изотопов самария с использованием ионообменных смол АВ 17×8 и КУ-2

The relevance of the research is caused by the need to develop a methodological base for determining 151Sm content in the soil cover of radioactively contaminated territories of Kazakhstan. The developed method for the determining of 151Sm will make it possible to assess the levels of soil contamination with this radionuclide, to determine the character of its spatial distribution, to allow estimating the internal exposure doses for the personnel and the population. The aim of the research is to carry out the isolation and radiochemical purification of samarium isotopes from acid solutions via using ion-exchange resins AV 17×8 and KU-2. Objects: salt solutions based on nitric and hydrochloric acid containing the stable isotopes of some natural, artificial β-emitters and isotopes of U and Th. The concentrations of nitric and hydrochloric acids were equal to the concentrations of the same acids used in the routine analysis of Pu and Am. Concentrations of chemical elements were determined using the Agilent 7700x quadrupole mass spectrometer and the iCAP 6300 Duo atomic emission spectrometer. The results of the experiments on the isolation and radiochemical purification of samarium isotopes from acidic solutions using anion-exchange resin AV 17×8 and cation-exchange resin KU-2 have been presented. It has been shown that the Sm-fraction can be purified from alkaline elements, Tl and U isotopes using the KU-2 cation-exchange resin. In turn, the isotopes U, Fe and Co can be removed using an anion exchange resin in 9M HCl media.

Kinetics of the Oxidative Degradation of KU-2×8 Cation-Exchange Resin Using Hydrogen Peroxide

Kinetics of the oxidative degradation of universal strongly acidic cation-exchange resin KU-2×8 is studied using hydrogen peroxide. The effect the nature and concentration of catalytic additives in the form of copper(II) and iron(II) salts have on the oxidation process is determined. It is found that in noncatalytic degradation, the effective rate constant rises from 0.24 × 10−3 to 7.54 × 10−3 g1/3 min−1 upon an increase in temperature in the range of 348–368 K. The activation energies of the noncatalytic oxidation of the cation-exchange resin with hydrogen peroxide are characteristic of a process that occurs in the kinetic region and total 132.46–141.96 kJ/mol. It is shown that introducing catalytic additives helps lower Ea of the process to 40.90 kJ/mol and the temperature of degradation by 15–25 K. The pattern of change in the surface morphology of the cation-exchange resin granules during oxidative decomposition is revealed. The approximate composition of the products of cation-exchange resin decomposition is identified via gas chromatography–mass spectrometry.

Isolation of Plutonium in the Course of REE/TPE Separation by Displacement Complexing Chromatography

Isolation of Pu from a TPE/REE mixture by displacement complexing chromatography on KU-2 cation-exchange resin was studied. To stabilize Pu in the trivalent state, the sorption of the mixture components from the initial solutions was performed in the presence of hydrazine nitrate. To convert Pu to the tetravalent state, H2O2 was added to the DTPA solution used as an eluent. The influence of temperature and H2O2 concentration on the chromatographic isolation of Pu was studied. Optimum conditions were found for separating Pu from TPE and REE.

Efficient fructose production from plant extracts by immobilized inulinases from Kluyveromyces marxianus and Helianthus tuberosus

The enzymatic hydrolysis of poly- and oligosaccharides from plants seems like an advantageous approach for sugars production. Two inulinases producing fructose from plant oligosaccharides were isolated from yeast Kluyveromyces marxianus and plant Helianthus tuberosus. Both enzymes were immobilized on polymeric carriers by using the static adsorption approach. We could save 80.4% of the initial catalytic activity of plant inulinase immobilized on KU-2 cation-exchange resin and 75.5% of yeast enzyme activity adsorbed on AV-17-2P anion-exchange resin. After immobilization, the Km values increased 1.5 and 6 times for enzymes from K. marxianus and H. tuberosus, respectively. The optimal temperatures for catalysis of both enzymes were increased from 48–50 °C up to 70 °C. The activities of both immobilized enzymes remained unchanged after the 10 cycles of 20-min hydrolysis reaction at 70 °C model batch reactor. Sorbents, native and immobilized enzymes did not exhibit any mutagenic or cytotoxic activity.

Synthesis of ethers and cyclic acetals in the presence of CBV-720 zeolite

СBV-720 zeolite was compared to H-Beta zeolite and KU-2 cation-exchange resin in the catalytic performance in addition of alcohols to norbornene, in condensation of aldehyde and ketone with di- and triols, and in the Prins reaction of olefins with formaldehyde. These reactions, when performed on СBV-720 zeolite, occur 1.5–2 times faster than on the other catalysts. The corresponding ethers and cyclic acetals were synthesized.

Tannery Wastewater Treatment, Picking and Galvanic Production from Chromium Ions by Sorption on the Anion Exchange Resin of the Brand AMP and Mixture of Anion Exchange Resin of the Brand AMP and Cation Exchange Resin of the Brand KU-2

There was investigated extracting of chromium ions from an aqueous salt solution Cr2 (SO4)3 and K2Cr2O7 and mixtures thereof. Using sorption on anion exchange resin of the brand AMP from solutions of salts mixtures Cr(III) and Cr(IV) with total chromium concentration of 500 mg/dm3 can be selectively extracted anions Cr(VI) for 20 – 30 minutes. Sorption by mixture of cation exchange resin KU-2 and anion exchange resin AMP improves the extraction of salts mixtures Cr(III), Cr(IV) with a substantial reduction of sorption time.

Separation of rare earth and transplutonium elements by displacement chromatography on KU-2 cation exchange resin in the Cu2+ form under ionizing radiation

Changes in chromatographic parameters (pH, REE concentration, eluent concentration, separation coefficients) under irradiation using the KU-2 cation exchange resin in the Cu2+ form are studied experimentally and theoretically depending on the absorbed dose and respective destruction of the eluent. It is found that the use of the cation exchange resin in the Cu2+ form in the field of ionizing radiation leads to a more effective separation of REEs than in the case of using the Zn2+ and H+ forms of cation exchange resin.

Sorption of I2 and CH3 131I on ion-exchange materials from aqueous solutions at 20°C

Sorption of I2 and CH3131I from aqueous solutions at 20°C on the materials obtained by modification of KU-2 cation-exchange resin was studied. It was found that these materials are able to absorb I2 both from distilled water and from a solution whose composition corresponds to the composition of aqueous coolant of the primary circuit of NPPs equipped with reactors of the WWER type, with the distribution coefficients Kd higher than 103 ml g−1 at the ratio V/m = 100 ml g−1. Practically complete absorption of I2 (>95%) is reached in 15 min. It was shown that AV-18 anion-exchange resin extracts CH3131 I from aqueous solution with a distribution coefficient Kd exceeding 300 ml mg−1 at the ratio V/m = 100 ml g−1.

Procedure for Simultaneous Determination of Uranium and Transuranium Elements in Groundwater and Liquid Radioactive Wastes from the Shelter

An ion-exchange procedure for simultaneous determination of 234U, 235U, 236U, 238U, 238Pu, 239 + 240Pu, 241Am, and 244Cm in groundwater and liquid radioactive wastes is described. The concentration and separation of U and Pu are performed on AV-17 anion exchanger in the chloride form from 9 M HCl. Am and Cm are separated from rare-earth elements by step-by-step elution from KU-2 cation-exchange resin in the NH 4 + form with α-hydroxyisobutyric acid (pH 4.75). Finally, U, Pu, Am, and Cm are determined α-spectrometrically.

Protein hydrolysates of castor bean seed and cottonseed meals

The processes involved in the hydrolysis of the proteins of the toxic seed meals of the castor-oil plant and the cotton plant with hydrochloric acid have been studied. The optimum conditions of hydrolysis, at which the yield of desired product amounts to about 40%, have been established. The use of activated carbon and the cation-exchange resin KU-2×8 have enabled a hydrolysate containing 80–85% of amino acids to be obtained.

Electromembrane extraction of Zn from Na-containing solutions using hybrid electrodialysis-ion exchange method

Extraction of Zn 2+ ions from solution containing Zn and Na sulphates in an electrodialysis cell, in which the desalination chamber was packed with ion-exchange resins, has been studied. The cation-exchanger KU-2 (Russia) and a mixture of the cation-exchanger KU-2 and the anion-exchanger AB-17 (Russia) were used during the experiments. With a mixed packing at lower than limiting current densities, the current efficiency for Zn ions reached 90% and dropped to 60% when a current density two times higher than the limiting value was used. Removal of Zn from the solution containing Na ions was most effective when the cation-exchange resin KU-2 was in the cell. Coating this resin with a polyelectrolyte had two effects on the generation of Zn hydroxide in the desalination chamber, namely, increase the transport of Na ions to the concentration chamber and a rise in pH in the desalination chamber. During the investigation into electric attraction of Zn hydroxide to the cation- exchange resin the conditions for effective recovery of Zn as a precipitate were established. The hybrid electrodialysis - ion-exchange method enabled the Zn ion concentration in the solution to be reduced almost 50- fold, that is from 1440 to 32 mg ∗l −1.

Gas-liquid chromatographic determination of products from alkylation of phenol by 1-decene

This article demonstrates how gas-liquid chromatography can be used for a quantitative analysis of the alkylate without removal of the unreacted starting materials (phenol and olefins). The cation exchange resin KU-2 was used as a catalyst to obtain an alkylate. The reaction was carried out in a single-pass flow unit at 130/sup 0/C with a 1:1 mole ratio of phenol to 1-decene and a space velocity of 0.5h/sup -1/. The alkylate obtained was distilled in a column with an efficiency of 25 theoretical plates, obtaining mono- and diisodecylphenol fractions. The compounds obtained were used in making artificial mixtures, in selecting the conditions for optimal separation of these mixtures, and in determining the detector sensitivity coefficients for these compounds. The analyses were performed in a Khrom-4 chromatograph. Relative correction factors are determined for the components of different chemical types (decenes, phenol, numberisodecyl phenyl ethers, monoisodecylphenols, diisodecylphenols). It is found that the relative error at a confidence level of 0.95 is no greater than 5%. Includes a table.

Surface activity and protective properties of oxypropylated alkylphenols

A number of commercial additives for mineral oils are currently being produced by the use of alkylphenols as starting materials. The use of oxypropylated alkylphenols as components of lubricating oils and additives has been reported [I, 2]. Alkylphenols are obtained by the catalytic alkylation of phenol with polymer distillate in the presence of benzenesulfonic acid (BSA) or the cation-exchange resin KU-2 [sulfonated styrene-divinylbenzene copolymer]. When the BSA is used, the reaction products contain about 40% dialkylphenols, in comparison with 3-8% when the KU-2 is used [3].

The determination of rare earth alloying additives in special steels by neutron activation analysis

A procedure for neutron-activation analysis of cerium, lanthanum, praseodymium and neodymium, tested on more than thirty samples of steels, is described. After irradiation for 20 hrs with a neutron flux of 1.2·1013 n·cm−2·sec−1 the steel samples were dissolved in aqua regia and extraction separation of iron from 6N HCl by ether was employed. The REE were separated as a group by precipitation as fluorides and hydroxydes. The individual rare-earth elements were separated from each other using a KU-2 cation exchange resin and a solution of ammonium α-hydroxyisobutirate as eluant. The separated samples were counted on a NaI(T1) γ-spectrometer.

Synthesis of coumarans from alkenylphenols

A number of substituted coumarans, the structures of which were confirmed by UV and PMR spectroscopy, were synthesized by the reaction of phenols with 4-vinyl-1-cyclohexene in the presence of KU-2 cation-exchange resin.

Triterpene glycosides ofBeta vulgaris

To elucidate the nature of the genin, the total glycosides were hydrolyzed with Kiliani's mixture. Chromatography in a thin layer of silica gel showed the presence of only oleanolic acid. Partition chromatography on alumina in the butanol-ethanol-ammonia (9 : 2 : 5) system with subsequent purification on KU-2 cation-exchange resin (in the H + form) yielded compounds A and B in the free state, and glycoside C contaminated with sucrose.

Distribution of the components of the water-organic solvent-mineral acid system between the phase of the cation exchange resin KU-2 and the external solution

1. The distribution of the components of the ternary system: water-organic solvent-mineral acid between the phase of the cation exchange resin KU-2 and the external solution of the components was studied in methanol, propanol, acetone, dioxane, and dimethylformamide solutions of hydrochloric and nitric acids and in dioxane and dimethylformamide solutions of sulfuric acid. 2. With increasing acid concentration, the selective sorption of water is reduced, while the absorption of the organic component is increased. 3. The sorption of the organic component depends on the thermodynamic and structural properties of the solutions. 4. With increasing concentration of the organic solvent, the selective sorption of water is increased. 5. The presence of a small amount of water causes a sharp asymmetry of the distribution curves.