Synthesis and ion exchange behaviour of polyaniline Sn(IV) arsenophosphate: a polymeric inorganic ion exchanger

Incorporation of a polymer material into an inorganic ion exchanger provides a class of hybrid ion exchangers with a good ion exchange capacity, high stability, reproducibility and selectivity for heavy metals. Such a type of ion exchanger ‘polyaniline Sn(IV) arsenophosphate’ has been synthesized by mixing polyaniline into inorganic material. This material is characterized using X-ray, IR, TGA studies in addition to ion exchange capacity, pH-titration, elution and distribution behaviour. On the basis of distribution studies, the material has been found to be highly selective for Pb(II). Kinetic study of exchange for the metal ions has been performed and some physical parameters such as self diffusion coefficient D₀, energy E_a and entropy ΔS* of activation have been determined.     

Synthesis,characterization and adsorption behaviour of TX-100 based Sn(IV) phosphate,a new hybrid ion exchanger

A new hybrid ion exchanger, Triton X-100 based tin(IV) phosphate (TX-100SnP) has been synthesized and characterized by ion exchange and physico-chemical methods such as ion exchange capacity, elution and concentration behaviour, IR, X-ray, TG/DTA and elemental analysis. Its adsorption behaviour has also been studied for some alkaline earths and heavy metal ions in different acidic media. It has been found generally more selective for metal ions as compared to tin(IV) phosphate prepared earlier. For Pb(II), Hg(II) and Fe(III) its selectivity has been found to be exceptionally good. On this basis, some binary separations have been performed involving these metal ions. Thermal studies show a high thermal stability of the material. It retains 54.54% of its i.e.c. at 200°C and 27.27% at 300°C.     

A Complexo-Ion Exchange Method for the Specific Detection of Iron on Zirconium (IV) Arsenophosphate Beads

Abstract

A highly sensitive and specific detection method has been developed for iron with a limit of detection ～ 0.0001 mg per 0.02 ml on the beads of siroomium(IV) arsemophosphate cation exchanger, utilizing its adserptie-iem-exchange properties and the complex forming ability of 1, 10-phenanthroline. A mechanism has also been proposed tentatively on the basis of some experimental observations and theoretical considerations.     

Synthesis and characterization of nano-composite ion-exchanger; its adsorption behavior

A novel organic-inorganic nanocomposite cation-exchanger has been synthesized via sol-gel method. It was characterized on the basis of FTIR, XRD, SEM, TEM, AFM and Raman studies. The structural studies reveal semi-crystalline nature of the material with the particle size ranging from 1-5 nm. Physiochemical properties such as ion-exchange capacity, chemical and thermal stability of composite material have also been determined. Bifunctional behavior of the material has been indicated by its pH titrations curves. The nanocomposite material exhibits improved thermal stability, higher ion-exchange capacity and better selectivity for toxic heavy metals. The ion-exchange material shows an ion-exchange capacity of 1.8 meq g(-1) for Na(+) ions. Sorption behavior of metal ions on the material was studied in different solvents. The cation exchanger was found to be selective for Pb(II), Hg(II) and Zr(IV) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) ion was found to be 0.85 and 2.85 μg L(-1). Analytically important separations of heavy metal ions in synthetic mixtures as well as industrial effluents and natural water were achieved with the exchanger. The practical utility of polyanilineZr(IV)sulphosalicylate cation exchanger has been established for the analysis and recovery of heavy metal ions in environmental samples.     

Etude photoelectronique de la separation du plomb et du cadmium par echange ionique sur le phosphate de hafnium: X-ray photoelectronic study of the separation of lead and cadmium ions on crystalline hafnium phosphate used as a cation exchanger

X-ray photoelectronic study of the separation of lead and cadmium ions on crystalline hafnium phosphate used as a cation exchanger.Crystalline hafnium monohydrogenphosphate monohydrate [Hf(HPO₄)₂·H₂O] is a useful cationic exchanger for separating lead(II) and cadmium(II) ions. Studies have been carried out at various pH and in the presence of various ligands. X-ray photoelectron spectroscopy has shown that lead diffuses into the deeper layers of the exchanger while cadmium remains near the surface. This property can be used to improve the selectivity of the method by masking cadmium with a large ligand (1,10-phenanthroline), which prevents the metal from adsorbing without any effect on lead fixation.     

THE TESTS AND MECHANISM ABOUT SODIUM IONS FROM AN ANION EXCHANGER

There exists a universal phenomena that sodium ions are leaked from the strong basic anion exdchanger in operation,which has been puzzling the researchers working in the field of water treatment for years.It is well known that the leakage of sodium ions will seriously affect the pruity of effluent.On the basis of lots of laboratory and industrial experiments,the mechanism of the sodium ions leaked from an anion exchanger has been preliminarily made out and some new chemical reaction equations as well as some improving measures have been put forward in this article.     

Ion-exchange resin catalysts in the liquid-phase hydrazinolysis of cinnamic acid

The catalytic activity of a synthetic ion-exchange resins has been studied in the reaction of cinnamic acid with hydrazine (aqueous medium, 363 K, 1.0–2.5 h) yielding the corresponding hydrazide. Efficient catalysts for the process are the anion-exchange resins AV-17-8 and AN-31. The modifying effect of the substrate—hydrazine hydrate—on the catalytic properties of the ion-exchange systems has been demonstrated. On the basis of IR spectroscopic studies, a plausible process mechanism was suggested. It involves polymer-bound quaternary ammonium ions of the anion exchanger.     

Hydrous zirconium oxide as an anion-exchanger

Samples of hydrous zirconium oxide have been prepared under varying conditions of precipitation, and their anion-exchange properties are reported. The effect of electrolyte concentration, time of equilibration and drying temperature on anion-exchange capacity has been studied. Stoichiometry of exchange, chemical stability and regeneration power of the exchanger have also been investigated. Distribution coefficients of various anions are reported, and some pairs of anions have been separated on the basis of the sorption data.     

Thin Later Chbomatography of Amino Acids on Tin(IV) Arsenosilicate Cation Exchanger in Some Buffer Solutions

Abstract

Inorganic ion exchanger tin(IV) arsenosillcate (TAS) has been used in the thin layer chromatographic study of 24 amino acids in various buffer solutions as the mobile phases. On the basis of the differential movement, some important binary separations of amino acids have been achieved, particularly those of basic fro acidic or neutral amino acids.     

Synthesis and characterization of zirconium(IV) iodovanadate and its use as electron exchanger

Samples of zirconium(IV) iodovanadate have been synthesized under varying mixing ratios by adding a mixture of aqueous solution of 0.1 M potassium iodate and 0.1 M sodium metavanadate to aqueous solution of 0.1 M zirconium oxychloride at pH 1. The ion exchange capacity of the material for Na⁺ ion was found to be 2.20 meq g⁻¹ of dry exchanger. The material has been characterized on the basis of chemical composition, FTIR and TGA. The chemical stability of the product has been checked in neutral, acidic and basic media. The product has been used as electron exchanger. The oxidation of Fe(II), Sn(II), ascorbic acid and thioglycolic acid was achieved by batch-equilibrium technique successfully. The maximum redox capacity of the exchanger has been found to be 4.20 meq g⁻¹ of exchanger by column process.     

弱碱性阴离子交换树脂的再生动力学

弱碱性阴离子树脂的优点是容易再生,但至今未见其再生动力学研究的报道。Hll通过光学方法观测到再生时树脂相内的动边界。从而肯定了用NaOH再生盐式弱碱性阴离子树脂是遵守层进机理的。以前的研究工作肯定了可以根据溶液中反离子浓度的变化来确定离子交换树脂的转换度,得到了适用于有限浴及离子交换剂颗粒半径保持恒定或不断随交换反应进行而变化条件下的速度表达式。适用于不同条件的由已反应层内的扩散控制的层进机理的离子交换反应的速度方程分别为: 1.无限浴及交换剂颗粒半径恒定条件下E(t)=1-3(1-X)~(2/3)+2(1-X)=6λD_eC_B~0t/(?) (1) 2.有限浴及交换剂颗粒半径恒定条件下     

Preparation and properties of lanthanum tungstate and studies of its ion-exchange and electrochemical behaviour

A new inorganic ion-exchanger lanthanum tungstate has been prepared by mixing lanthanum nitrate and sodium tungstate. The refluxed product has been found to be most suitable; therefore, most of the electrochemical and ion-exchange studies were performed on this product. The material is a weak cation exchanger with a capacity of 0.80 mmol per gram. Electrochemical studies are performed by preparing a pellet of this exchanger in polystyrene; charge density and membrane potential have been calculated. The results are discussed.     

Separation and Recovery of Some Metal Ions Using Pan Sorbed Zinc Silicate as Chelating Ion Exchanger

Abstract

A new inorganic ion exchanger zinc silicate has been synthesized. Its properties such as ion exchange capacity, heat effect and stability etc. have been studied. Sorption of PAN over zinc silicate formed a chelate ion exchanger which showed greater selectivity for some metal ions especially for Cu²⁺, Ni²⁺, Co²⁺, Fe³⁺, Ag⁺, Ag³⁺ and Pt⁴⁺. Selectivity has been determined on the basis of distribution coefficients of these metal ions. Separations of Pt(IV) from Fe(III), Au(III) from Fe(III), Ag(I) from Cu(II) and Au(III) from Cu(II) have been reported. The recovery of Pt(IV) and Au(III) from dilute solutions has also been studied.     

Application of tracer packet technique for multielemental uptake studies by ceric vanadate

We have synthesized and characterized an inorganic ion-exchanger, ceric vanadate. The exchanger is stable towards thermal, chemical and radiation doses within the appreciable working range. The molecular formula of the ceric vanadate has been formulated as 4CeO₂·5V₂O₅·12H₂O. Multi elemental uptake studies by the newly synthesized exchanger have been carried out using “tracer packet” technique. It has been found that the exchanger is highly suitable in removing Tl, Pb, Bi and Po. However, the uptake of Cu and As by the exchanger is moderate while that of Hg, Zn, Ga, Ge, and Se has been found negligible.     

Studies on sorption of plutonium from carbonate medium on polyacrylhydroxamic acid resin

Polyacrylhydroxamic acid resin synthesized by functionalization of polyacrylamide with hydroxylamine has been investigated for the sorption of plutonium(IV) from carbonate medium, aiming at its application for the removal of plutonium from alkali wash effluent generated during purification of TBP in PUREX process. Batch experiments have been carried out to determine distribution coefficient of plutonium(IV) between this exchanger and various compositions of carbonate medium. Effect of the concentration of sodium carbonate, sodium bicarbonate and pH of the solution on the distribution coefficient have been studied to optimize the conditions for the uptake of Pu(IV) by this exchanger. Column experiments were carried out to determine the practical capacity of the exchanger for plutonium. Elution studies were also carried out to recover the loaded plutonium from the ion exchange column The exchanger displayed good exchange capacity for Pu(IV) from feed solution simulating the conditions of carbonate wash effluent generated in PUREX process. The exchanger also exhibited fast elution of Pu, suggesting the feasibility of using it for the recovery of Pu from carbonate based wash effluent.     

Selective cation exchange separation of bismuth on zirconium hexacyanoferrate(III) column

A new inorganic ion exchanger, zirconium hexacyanoferrate(III) prepared by adding potassium hexacyanoferrate(III) to zirconium oxychloride at 80°C has been found to be stable in acids and salt solutions. Distribution coefficient values determined for various metal ions show that the exchanger has a high affinity for bismuth. Binary separations of Bi(III) from a number of other metal ions at different concentrations were achieved on the column of the exchanger. Thus the exchanger has been found useful for the separation of bismuth from a large number of metals.     

Synthetic Inorganic Ion-Exchangers XV. Thin-Layer Chromatography of Metal Ions on Thorium Tungstate: Quantitative Separation of Hg(II) from Several Other Metal Ions

Abstract

The analytical application of Thorium tungstate as an ion exchanger has been explored by thin-layer chromatographic (TLC) technique. Binder-free thin layers of thorium tungstate have been employed for some important binary and ternary separations. Quantitative separation of Hg(II) from the mixture of several other metal ions has been achieved.     

Effect of soluble calcium on the determination of the labile metal content of sediments with ion-exchangers

Equilibration of sediments with cation-exchangers results in a transfer of loosely bound labile metal species to the exchanger phase. Dissolution of the matrix is also promoted and selectivity rules suggest that some of the cations released (particularly Ca) could effectively compete with metal ions for exchange sites. This potential source of error has been evaluated by studying synthetic mixtures of Ca²⁺ and other metal ions (Cu²⁺, Pb²⁺, Cd²⁺, Zn²⁺) and by analysis of two calcium-rich wastes (a calcine and a jarosite). The ion uptake most influenced by calcium competition was that of zinc; uptake of lead was least affected. For minimum error, i.e., optimum transfer of “available” or “labile” metal ion, the level of free Ca²⁺ introduced into the solution should not exceed 300 mg/l., and the amount of exchanger added must provide an excess of exchange sites relative to the amount of cations released from the sample. By use of exchangers of different types it is possible to attempt some classification of the labile metal content, e.g., acid-displaced, exchangeable, salts of weak acids.     

新型复合无机离子交换剂磷锑酸——磷钼酸铵的合成与性能研究

本文研究了新型复合无机离子交换剂磷锑酸—磷钼酸铵（ＰＡＡ—ＡＭＰ）的制备和对１３７Ｃｓ＋的交换性能。这种交换剂成型好且稳定，对Ｃｓ＋有良好的选择性和较高的交换容量，与以前的四价金属磷酸盐类复合材料相比，它吸附Ｃｓ＋后可直接用浓度高的ＨＮＯ３洗脱下来，实现了低酸交换吸附，高酸淋洗再生的工艺要求，是一种性能优良的无机离子交换材料，可从放射性废液中分离和回收（１３７）Ｃｓ＋。     

偏钛酸型锂离子交换剂表面性质与选择吸附性研究

本文采用Li渗入于TiO2经高温热力学重结晶制备偏钛酸型锂离子交换剂,其对碱金属、碱土金属溶液中的Li+ 具有特殊选择吸附性,其次序为Li+>Mg2+>Ca2+>Na+,K+。对交换剂表面性质以及Li+ 在固-液界面的选择吸附特性进行了研究。通过对某气田卤水提锂实验表明:该交换剂对低Li+ 含量卤水中Li+ 的选择性吸附效果显著,对Mg2+、Ca2+、Na+、K+ 的分离效果好,Li+ 的富集倍数达9倍,并具有较好的循环稳定性。