Synthetic Inorganic Ion Exchangers Research Articles

Stronsiyum gideriminde sentetik inorganik iyon değiştiricilerin kullanımı

Strontium-90 is the most dangerous radioactive isotope of strontium, which is formed during the operation of nuclear reactors. It can also spread to the environment due to fallout from nuclear accidents and nuclear weapons tests. Removal of hazardous radionuclides and safe management of radioactive waste is a vital necessity. Ion exchange has been one of the most used methods in the management of liquid radioactive waste. Inorganic ion exchangers stand out for their thermal, chemical and radiation resistance. They show selectivity for certain cations. This review focused on removal of 90Sr by synthetic inorganic ion exchangers such as zeolites, titanates, titanosilicates, other acid salts, hydrous oxides and metal sulfides. Overall, more than 100 publications are reviewed and detailed data on strontium removal using inorganic ion exchangers are presented.

Isotherm and kinetic sorption of some lanthanides and iron from aqueous solution by aluminum silicotitante exchanger

ABSTRACTSorption of La3+, Eu3+, and Fe3+ onto new synthetic inorganic ion exchange material of aluminum silicotitante was investigated. The aluminum silicotitante (EX1, EX2, and EX3) are synthetic with different concentration ratio (0.1:0.1:0.003, 0.1:0.1:0.1, and 0.1:0.1:0.1) at aging time 4, 4, and 1 day, respectively. The equilibrium kinetic for La3+, Eu3+, and Fe3+ onto EX1, EX2, and EX3 materials takes about 120 min which is considered as a fast kinetic process. Sorption results were fitted using different kinetic models such as pseudo-first-order, pseudo-second order, and intraparticle diffusion models. The results indicated that the sorption of La3+, Eu3+, and Fe3+ onto EX1, EX2, and EX3 materials is highly fit with the pseudo-second order model. Equilibrium data were described by the Langmuir, Freundlich isotherm models. The Langmuir isotherm model was fitted to the experimental data better than the Freundlich isotherm. The thermodynamics parameters (positive values of ΔH°, ΔS° and negative values of ΔG°) indicated the binding systems between the materials and adsorbate were endothermic, entropy gained and spontaneous in nature. The experimental data indicated that, aluminum silicotitante could be used as an efficient sorbent for La3+, Eu3+, and Fe3+. Maximum sorption % at equilibrium is 92.7, 99.0, and 78.5% for La3+, Eu3+, and Fe3+, respectively.

Radiochemical sequential separation of Tl (I), In (III) and Sr (II) from a mixture by adsorbing on synthetic inorganic ion-Exchangers

The present work aims at radiochemical sequential separation of Tl (I), In (III) and Sr (II) from a mixture by employing synthetic inorganic ion-exchanger. Zirconium phosphosilicate and zirconium phosphate has been synthesized and their composition has been determined.204Tl, 114mIn and 85+89Sr have been used as tracers for optimizing the ideal conditions in the adsorption. Reproducibility of maximum adsorption at ideal conditions were found as 91.67 ± 2.08% for Tl (I) and 94.48 ± 2.8% for In (III) on zirconium phosphosilicate whereas 91.30 ± 2.0% for Sr (II) on zirconium phosphate. The radiochemical purity has been determined by gamma ray spectra or aluminium absorption curve after sequential separation.

Removal of selenium and iodine radionuclides from waste solutions using synthetic inorganic ion exchanger

79Se and 129I are potentially important anionic radionuclides in safety assessments due to its radiotoxicity, high mobility and long half life's (3.27×105 and 1.7×107years, respectively). This study has examined the sorption potential of synthetic microporous inorganic exchanger for 75Se (t1/2 120days) and 125I (t1/2 60.2days), as a surrogate for 79Se and 129I. The exchanger was synthesized by sol–gel method and characterized using scanning electron microscope (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD); nitrogen physisorption measurements (BET), Fourier transform infrared spectroscopy (FTIR) and finally thermal analysis. Batch mode sorption was completed to estimate the effects of the system variables. Kinetic models were applied to check the sorption rate data. The equilibrium sorption results obtained were also tested using isotherm models. The monolayer capacity (Qmax) values are 43.5 and 62.5mg/g for 75Se and 125I, respectively. Sorptive removal of 75Se and 125I from contaminated tap water and environmental water samples approved the legality of the results acquired in these batch mode studies. The results showed, in a situation of emission of anionic radionuclides to the natural environment the synthetic inorganic exchanger could act as a succeeded and economical adsorbent for retention of different anionic radionuclides such as 79Se, 129I, 36Cl and 99Tc.

Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger.

A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate, a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography (TLC). A mixture of methanol and 0.1 mol/L formic acid (3:7, v/v) was employed as the mobile phase. The development time was 32 min. The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength (λ) of 410 nm. The isoproterenol recovery in this procedure was 98.9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD) was less than 0.94. The limit of detection (LOD) and limit of quantification ( LOQ) were 7.7 x 10(-7) mol/L and 3.85 x 10(-6) mol/L, respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

Separation and determination of streptomycin by ion exchange-high-performance thin-layer chromatography

A simple and highly sensitive method is developed for the determination of streptomycin in dosage forms and in biological fluids using ion exchange-high-performance thin-layer chromatography (IE-HPTLC). The method involves the use of titanium(IV) silicate (a synthetic inorganic ion exchanger) coated plates and a mixture of KBr (0.5 m) and ethanol (9:1, ν/ν) as mobile phase. The development time was 18 min. Quantitative measurements were made using a CAMAG TLC Scanner-3 at 359 nm. The streptomycin recovery from the total procedure was equal to 97.9%. The procedure is quantitatively characterized, the linearity was r2 > 0.99, and the relative standard deviation (RSD) was <0.94. The limit of detection (LOD) and limit of quantification (LOQ) were 2.4 and 12 ng, respectively.

Thorium Uptake on Synthetic Inorganic Ion Exchangers

Birnessite, antimonysilicate, and their cation-exchange derivatives were tested to take up thorium. Sorption experiments were performed in different concentrations of acid, sodium, potassium, and calcium nitrate solutions in order to evaluate the influence of cations that are likely to be present in waste effluents. Variation in the magnitude and mechanism of thorium sorption on the exchangers was ascribed to structural differences and the exchange properties of the materials, as well as the aqueous chemistry of thorium. The work included investigation of thorium solution' pH in controlling the sorption process. In acidic solutions, H-antimonysilicate proved to be the best sorbent. The structure of M-H-birnessite allows facile mobility of the interlayer cations with little structural rearrangement, making it of great importance for ion-exchange use in salt conditions. Potassium had the most, and sodium the least effect on thorium selectivity by birnessites, when they are present as macro components. Conversely, calcium ions did greatly inhibit the sorption behavior of thorium on Ca-antimonysilicate. Studying the effect of thorium solution' pH reflected the fact that the microcrystal modifications of birnessites occurred during experiments. In summary, H-birnessite showed superior uptake for thorium in comparison to other materials investigated in the literature, which reflects the characteristics of the material selectivity.

Determination of ampicillin and amoxicillin by high-performance thin-layer chromatography

Summary A simple and fast high-performance thin-layer chromatographic method has been developed for the simultaneous determination of ampicillin and amoxicillin. Titanium(IV) silicate (a synthetic inorganic ion-exchanger)-coated thin-layer chromatography (TLC) plates were used to separate them, employing a mixture of K2HPO4 (0.1 M) + KH2PO4 (0.1 M), 1:1 (υ/υ), as mobile phase. The development time was 18 min. The plates were sprayed with fresh 1% solution of ninhydrin in ethanol. The developed method enables highly contrasted chromatograms with red purple spots in white background. Densitometric measurements were made at wavelength 546 nm using Camag TLC Scanner-3. The ampicillin and amoxicillin recovery of the total procedure were equal to 99.99 and 100.43, respectively. The procedure is quantitatively characterized. Linearities were r2 > 0.9958 and 0.9954 for ampicillin and amoxicillin, respectively, and the relative standard deviations were <0.89 and 0.61, respectively. The limits of detection were 2.9...

ChemInform Abstract: Synthetic Inorganic Ion-Exchange Materials. Part 60. Ion Exchange and Chromatographic Separation of Alkali Metal Ions on Cubic Ammonium Molybdate. A Novel Cation Exchanger.

ChemInform Abstract: Synthetic Inorganic Ion-Exchange Materials. Part 60. Ion Exchange and Chromatographic Separation of Alkali Metal Ions on Cubic Ammonium Molybdate. A Novel Cation Exchanger.

Ion-exchange studies of 110mAg(I) using synthetic inorganic ion-exchanger

In the present investigation, the selective adsorption of silver on synthetic inorganic ion exchanger, zinc(II) ferrocyanide, has been established by batch method, under specific conditions, using 110mAg as a tracer. The efficiency of adsorption has been determined by γ-ray spectrometry and was found to be greater than 96%. The Ag(I) uptake by the exchanger has also been evaluated. The selectivity of the method was checked by studying the adsorption of Ag(I) in the presence of a number of foreign ions using their corresponding tracers. The interfering ions were removed by washing the ion-exchanger with appropriate reagents, so that it could be applied for the determination of trace amount of Ag(I) in complex matrices, containing trace amount of other metal ions.

Quantitative TLC of toxic elements on inorganic ion-exchangers. VI. Separation and determination of cadmium

Increasing contamination of drinking water, food, and the environment with toxic elements has led to a demand for fast and selective analytical methods [1–4]. Interest in cadmium is increasing because of its fatal toxicity [5]. The effects of acute cadmium poisoning are manifested in a variety of different symptoms including high blood pressure, kidney damage, and destruction of red blood cells [6]. Exposure to small doses of cadmium also slowly causes emphysema, anosmia, and nephropathy [7]. Separation and determination of cadmium in biological and environmental matrices have therefore aroused much interest [3]. Effective HPLC methods for detection and determination of cadmium have recently been reported [8, 9]. A theoretical model have also been established for predicting the retention behavior of EDTA-complexed anions of toxic metals [9]. Much of the chromatography of metal complexes and other difficult ionic separations will remain unpredictable, however, until definite studies of their retention behavior have been made. Use of new synthetic inorganic ion-exchangers as adsorbents in thin-layer chromatography has transformed this technique into a rapid and selective means of separation and determination of metal ions [10–16]. In continuation of our studies on chromium [16], we report here rapid and selective TLC method using titanium silicate [17], an inorganic ion-exchanger, for separation and determination of cadmium in the presence of numerous elements. 2 Experimental

Investigation of the resistance of some naturally occurring and synthetic inorganic ion exchangers against gamma radiation

The effect of various doses of gamma radiation on the ion-exchange capacity, distribution coefficient values, elution behaviour, physical effect, pH titration and infrared spectra of some synthetic inorganic ion exchangers, namely the cerium substituted phosphates; and naturally occurring inorganic ion exchangers, zeolites from different parts of Iran, have been studied systematically. No significant change has been observed in the ion-exchange capacity (with the exception of CeP(Na), CeP(Di·Na) and zeolite 5 (deposits of arababad talas)), elution behaviour, physical effect, chemical stability and the infrared spectra of the synthetic ion exchangers irradiated upto a total dose of 200 kGy, while a change has been observed in the pH-titration and distribution behaviour. The increase in pH is sharper for irradiated samples with divalent cations than for the normal samples. Furthermore, the K d values, and hence the selectivity towards certain cations increase with the total dose absorbed, reaching its optimum selectivity with the dose of 50–100 kGy. The natural zeolites chosen for these studies, show, similar pattern to those of synthetic ion exchangers, and in some cases an extremely high selectivity toward certain cations, like Be II. These make, zeolites, which are naturally occurring ion exchangers more viable economically, and extremely useful alternative in this industry.

Sorption of 60Co on a synthetic titanosilicate analogue of the mineral penkvilksite-2O and antimonysilicate

The ability of two different types of synthetic inorganic ion-exchangers to sorb radioactive cobalt-60 using a batch-type method was studied. The two materials examined were the analogue of the natural titanosilicate penkvilksite-2O (AM-3) and a synthetic antimonysilicate. Ion-exchange experiments were performed with solutions labelled with radioactive cobalt (60Co). The sorption of 60Co onto the two samples materials were compared in terms of distribution coefficient (K d), sorption percentage and cobalt quantity removed in mg per gram weight of the material. Several parameters were investigated viz. contact time, cobalt concentration, and sorbent concentration. It was found that the batch factor and cobalt concentration had a significant influence on the sorption of cobalt onto both of the materials. This was associated with the difference in pH generated by suspensions of the materials in water which was alkaline for the penkvilksite-2O analogue, and acid for the synthetic antimonysilicate.

Synthetic inorganic ion exchange materials XLIV: synthesis and ion exchange properties of cubic niobic acid (HNbO 3)

A cubic niobic acid (C-NbA) was synthesized by Li +/H + ion exchange reaction with an 8 M (mol dm −3) nitric acid solution from LiNbO 3. The LiNbO 3 was obtained by heating a mixture of Li 2CO 3 and Nb 2O 5 with molar ratio of 1:1 at 900°C for 24 h. X-ray diffraction pattern of C-NbA was indexed to a cubic structure (space group Im3), with the lattice constant a 0 = 7.6445 Å (Å = 100 pm). The C-NbA product showed an exchange reaction equivalent to one proton per one Li + in a mixed solution of lithium nitrate and lithium hydroxide. The pH titration curves of C-NbA on the Li +/H + exchange system indicated a weak monobasic acid. C-NbA showed high uptake for lithium ions, whereas no appreciable amount of uptake was observed for other alkali metal ions in the pH range 4–12. An extremely high selectivity was found for lithium ions, and the separation factor (α) of lithium ions to other alkali metal ions was higher than 10 3.

Removal of Sr 2+, Ca 2+, and Mg 2+ from aqueous and aqueous-alcoholic saline media

Synthetic inorganic ion exchangers have special uses and can be valuable in some trace separations. Zeolite NaA is used in an ion exchange study with Sr 2+ , Ca 2+ , and Mg 2+ in aqueous Nacl media of ionic strengths, 1, 2, 3, 4, and 5, and in the oversaturated range of 7 and 10 m . A mixed aqueous methanol, ethanol, n-propyl alcohol, and n-butyl alcohol, 1 m NaCl medium has been investigated with the aim of studying the effect of changing the dielectric constant of the medium on the uptake of the studied cations, which are present in trace concentrations in caustic soda manufactured by the selective membrane technique. The temperature effect on uptake shows an endothermic character for the exchange reactions under investigation.

Synthetic inorganic ion exchange materials XLI: Ion exchange properties of cubic tantalic acid (HTaO 3)

Cubic tantalic acid (C-TaA) was synthesized by Li + H + ion exchange reaction with a 3 M (mol dm −3) sulfuric acid solution from LiTaO 3. The LiTaO 3 reactant was obtained by heating a mixture of Li 2CO 3 and Ta 2O 5 with molar ratio of 1:1 at 700, 800, and 900 °C. The X-ray diffraction pattern of C-TaA was indexed as cubic (space group Im3), with the lattice constant a 0 = 7.75 – 7.62 Å. The C-TaA product showed an exchange reaction equivalent to one proton per one Li + in a mixed solution of lithium nitrate and lithium hydroxide. The pH titration curves of C-TaA on the Li + H + exchange system indicated a weak monobasic acid. C-TaA showed high uptake for lithium ions, whereas no appreciable amount of uptake was observed for other alkali metal ions in the range studied of pH 4–12. An extremely high selectivity was found for lithium ions, and the separation factor (a) of lithium ion to other alkali metal ions was higher than 10 3.

Strontium binding properties of inorganic adsorbents

A comparison of strontium sorption on synthetic inorganic ion exchangers and zeolites from 0.01M CaCl2 solution, sea water and an artificial foodstuff fluid has been carried out in batch and column experiments. It was found that some adsorbents among the groups manganese dioxides, mixed titanium-manganese oxides, antimony-based materials and synthetic zeolites had the highest selectivity to strontium (K d >1000). These adsorbents are interesting for further investigation concerning their use for radiostrontium decontamination of foodstuffs (if nontoxic), as well as for analytical purposes.

Synthetic Inorganic Ion Exchangers Showing High Selectivity towards 5f Elements

Synthetic Inorganic Ion Exchangers Showing High Selectivity towards 5f Elements

Synthetic Inorganic Ion-Exchange Materials. LVIII. Hydrothermal Synthesis of a New Layered Lithium Titanate and Its Alkali Ion Exchange

Abstract A new crystalline hydrous lithium titanate, (Li1.81, H0.19)Ti2O5·2.2H2O, was synthesized hydrothermally at 190 °C by a reaction of hydrous titanium dioxide with LiOH solution. The compound has a layered structure and showed a C–base-centered orthorhombic system with the lattice constants, ao=16.66±0.02 Å, bo=3.797±0.002 Å, and co=3.007±0.003 Å. The lattice constants were changed to ao=18.08±0.03 Å, bo=3.784±0.003 Å, and co=2.998±0.002 Å upon conversion to the hydrogen form. The 8.5% increase in the ao value along the a axis suggests a layered structure. A hypothetical structure was proposed. The H+ form showed the ion-exchange selectivity at an ionic strength of 0.1 in the order of K+&amp;lt;Na+&amp;lt;Li+ at pH&amp;gt;6 and Li+&amp;lt;K+&amp;lt;Na+ at pH&amp;lt;6.

Adsorption and desorption method for cacodylic acid with inorganic ion exchangers

AbstractSynthetic inorganic ion exchangers were studied regarding adsorption and desorption features of cacodylic acid [(CH3)2A3O(OH)] with a view to finding a selective adsorbent in aqueos solution. Hydrous oxides of titanium [Ti(IV)], Zirconium [Zr(IV)], manganese [Mn(IV)] and ion [Fe(III)] among synthetic inorganic ion exchangers showed a high selectivity towards cacodylic acid over a wide pH range lower than 12. A large capacity for cacodylic acid (1.0 mmol g−1) was observed for amorphous hydrous titanium dioxide (Am‐HTDO) at pH &lt; 5.5 in a solution of ionic strength of 0.1 made with (NaCl + HCl) or (NaCl + NaOH). The uptake by the column method (0.9 mmol g−1) was in good agreement with the batch method. The acid could be quantitatively eluted by 1 mol dm−3 NaOH.