K. G. Varshney

The adsorption of phosphamidon on the surface of styrene supported zirconium (IV) tungstophosphate: a thermodynamic study

Adsorption thermodynamics has been studied on the beads of hybrid inorganic ion exchanger: styrene supported zirconium (IV) tungstophosphate for a pesticide phosphamidon at 30, 45 and 60°C. As a result some thermodynamic parameters like Freundlich constants, thermodynamic equilibrium constant (K0), standard free energy changes (ΔG0), standard enthalpy change (ΔH0) and standard entropy changes (ΔS0) have been evaluated.

Synthesis, characterization and analytical applications of lead (II) selective polyacrylonitrile thorium (IV) phosphate: a novel fibrous ion exchanger

Abstract Some investigations on the preparative procedures of fibrous polyacrylonitrile thorium (IV) phosphate (PANThP) are reported. This new fibrous ion exchanger has been characterized on the basis of SEM and the ion exchange studies. The distribution studies reveal that the exchanger is highly selective for Pb(II). On this basis some useful binary separations of Pb(II) from other metal ions have been performed on its column indicating its useful environmental applications.

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 Ea and entropy ΔS* of activation have been determined.

Kinetics of adsorption of phosphamidon on antimony (V) phosphate cation exchanger: evaluation of the order of reaction and some physical parameters

Abstract The kinetics of adsorption of the pesticide phosphamidon on beads of antimoy (V) phosphate cation exchanger have been studied. Physical parameters such as order of reaction, rate constant, activation energy, enthalpy of activation, entropy of activation and free energy of activation have been obtained. The adsorption behaviour is found to be second order during the first 15 min and thereafter, up to 180 min, it is first order.

Acrylonitrile based cerium (IV) phosphate as a new mercury selective fibrous ion-exchanger: Synthesis, characterization and analytical applications

Abstract Acrylonitrile based cerium (IV) phosphate has been synthesized as a new fibrous ion-exchanger. It has been characterized using X-ray, IR, TGA and DTG studies in addition to its ion-exchange capacity, elution behaviour, pH titration and distribution behaviour. Separation factors and Kd values for various metal ions have also been determined and a marked selectivity for Hg2+ has been found. As a consequence, some binary separations of metal ions have been performed on a column of this material, demonstrating its analytical potential.

Synthesis, composition and ion exchange properties of Sn(IV) and Cr(III) arsenophosphates: separation of metal ions

Abstract This paper deals with the synthesis of the arsenophosphates of various metals. The chemical composition, ion exchange capacity, thermal stability, concentration curves, elution curves, pH-titrations and IR studies have been performed on two materials, namely, Sn(IV) arsenophosphate and Cr(III) arsenophosphate. Their utility has been established by achieving four binary separations of industrial importance such as CuNi, FeCu, FeNi and CoNi on columns.

Synthesis, Ion-Exchange Behavior, and Analytical Applications of a New, Crystalline, and Stable Zirconium(IV) Arsenosilicate Cation-Exchanger: Analysis of Some Silicate Rocks

Abstract A new crystalline inorganic ion-exchanger, Zr(IV) arsenosilicate, has been synthesized and shows high chemical and thermal stability. It is also stable under γ-radiations of moderately high strength. The utility of this material has been demonstrated by achieving quantitative separation of Hg(II) from such other metal ions as Cd(II), Pb(II), Ni(II), Co(II), Zn(II), Al(III), and Fe(III) on its columns. Some silicate rocks have also been analyzed using this material.

Cation-Exchange Study on a Crystalline and Thermally Stable Phase of Antimony Silicate. Effect of Irradiation on Ion-Exchange Behavior and Separation of Cd(II) from Zn(II) and Mn(II) and of Mg(II) from Ba(II), Ca(II), and Sr(II)

Abstract A systematic ion-exchange study has been performed on antimony silicate, which includes its ion-exchange capacity, elution behavior, pH titrations, and distribution coefficients of common metal ions. The Kd values for alkali metals vary with the pH of the solution and the material is found to be highly selective for Rb(I) at pH values greater than 1. On the basis of distribution studies, the separation of Cd(II) from Zn(II) and Mn(II) has been achieved. Similarly, Mg(II) has been separated from Ba(II), Ca(II), and Sr(II) to illustrate its utility. Antimony silicate is very stable both thermally and chemically and possesses reproducible ion-exchange properties; also, the effect of irradiation on the ion-exchange behavior is negligible. A tentative formula of the material has also been proposed based on chemical, infrared, and thermogravimetric analysis studies. The x-ray studies reveal that the exchanger is crystalline with a d-value of 6.09 A.

Kinetics of ion-exchange of alkaline earth metals on antimony(V) phosphate cation exchanger

Forward and reverse ion exchange kinetics of Mg(II), Ca(II), Sr(II) and Ba(II) exchange with H(I) has been studied on antimony(V) phosphate cation exchanger applying the Nernst-Planck equations. As a result, some kinetic parameters like diffusion coefficients, activation energies, and entropies of activation have been evaluated under the conditions favoring a particle diffusion-controlled mechanism. Such kinetic parameters have also been compared with the kinetic parameters of different single and double salts.

Radiation stability of some thermally stable inorganic ion exchangers

Effect of various doses of gamma radiation on the ion-exchange capacity, distribution coefficient values, elution behaviour, pH titration and infrared spectra of some thermally stable inorganic ion exchangers has been studied systematically. No change has been observed in the ion-exchange capacity, elution behaviour and the infrared spectra of the materials irradiated up to a total dose of 3·108 rad, while, a change has been observed in their pH-titration and distribution behaviour.