The Effect of Temperature on Ion Exchange Equilibria. III. Exchanges Involving Some Divalent Ions

In the present investigation, attempts were made to understand the difference in bromide ion selectivity of the two closely related anion exchange resins Auchlite ARA-9366 and Auchlite A-378 in chloride form. The selectivity difference was predicted based on the thermodynamic equilibrium constants and enthalpy values of Clˉ/Brˉ ion exchange reactions performed by using the two resins. During Clˉ/Brˉ exchange reactions, with rise in temperature from 30.0 °C to 45.0 °C, the equilibrium constant (K) values were observed to decreases from 8.15x10 -2 to 6.06x10 -2 for Auchlite ARA-9366 resins and from 2.16x10 -2 to 1.10x10 -2 for Auchlite A-378 resins. The decrease in K values with rise in temperature, indicate exothermic ion exchange reactions having enthalpy values of -36.14 and -18.38 kJ/mol respectively. The high K and low enthalpy values obtained for Auchlite ARA-9366 resins indicate their greater selectivity for the bromide ions in the solution as compared to Auchlite A-378 resins.

Section: Resultsmentioning

confidence: 99%

Ion-Exchange Reaction Thermodynamics to Study the Selectivity Behaviour of Nuclear and Non-Nuclear Grade Anion Exchange Resins

Singare¹,

Patange²

2014

“…Attempts were also made to study the temperature effect on anion exchange systems [65][66][67][68][69][70][71][72][73] for computing the thermodynamic equilibrium constants. However very little work was carried out to study the equilibrium of cation exchange systems [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64]. Therefore, in the present investigation, attempts were made to understand the thermodynamics of uni-univalent and uni-bivalent ion exchange reactions using the nuclear grade cation exchange resin Indion-223.…”

Section: Introductionmentioning

confidence: 99%

Study of Uni-Univalent H+/K+ and Uni-Bivalent H+/Mg2+ Ion Exchange Reactions Using Nuclear Grade Resin Indion-223

Singare¹,

Mohammed²,

Dixit

2014

In the present paper the uni-univalent and uni-bivalent ion exchange reactions were investigated using nuclear grade anion exchange resin Indion-223 in H + form. For both H + /K + uni-univalet ion exchange reactions and H + /Mg 2+ uni-bivalet ion exchange reactions, the equilibrium constant K values increases from 0.01710 to 0.02374 and from 0.000177 to 0.000333 respectively as the reaction temperature rises from 35.0 °C to 45.0 °C. The increase in K values with temperature suggest endothermic ion exchange reactions having the enthalpy change values of 22.72 and 51.46 kJ/ mol respectively. The results of such studies will help in selection of suitable ion exchange resins in order to bring about efficient separation of different ionic species present in the waste water effluents released from nuclear as well as chemical process industries.

“…Attempts were also made to study the temperature effect on anion exchange systems [38][39][40][41][100][101][102][103][104][105][106][107][108][109][110][111] for computing the thermodynamic equilibrium constants. However very little work was carried out to study the equilibrium of cation exchange systems [85][86][87][88][89][90][91][92][93][94][95][96][97][98][99]. Therefore, in the present investigation, thermodynamics study of uni-bivalent ion exchange reactions was made to predict the selectivity behaviour of strongly acidic gel type nuclear grade cation exchange resin Indion-223 towards some divalent ions in the solution.…”

Section: Introductionmentioning

confidence: 99%

Study on Preferential Selectivity of Nuclear Grade Resin Indion-223 towards some Bivalent Ions

Singare¹,

Mohammed²,

Dixit

2014

In the present paper attempts are made to understand the selectivity of nuclear grade cation exchange resin Indion-223 in H + form towards Ca 2+ and Mg 2+ bivalent ions in the solution based on thermodynamic concept. It was observed that with rise in temperature the equilibrium constant K values for H + /Ca 2+ uni-bivalet ion exchange reactions increases from 0.000397 to 0.000639. Similarly for H + /Mg 2+ uni-bivalet ion exchange reactions the equilibrium constant K values increases from 0.000177 to 0.000333. The increase in equilibrium constant values with rise in temperature indicate endothermic ion exchange reactions having the enthalpy change values of 38.92 and 51.46 kJ/ mol respectively. The difference in K values and enthalpy values were used to predict the selectivity behaviour of the resin towards the Ca 2+ and Mg 2+ bivalent ions in the solution. The thermodynamic concept of the present study can be applied to understand the selectivity behaviour of different nuclear as well as non-nuclear grade resins towards wide range of ionic species present in the exchanging liquid medium.