Effect of temperature on ion exchange equilibrium between AMX membrane and binary systems of Cl−, NO− 3 and SO2− 4 ions

TLDR: In this paper, the effect of temperature variation on ion exchange equilibrium between an anion exchange membrane and solutions of electrolytes containing the most dominant anions of natural waters (CI−, NO− 3 and SO2minus; 4) was studied.

Abstract: The effect of the temperature variation on ion exchange equilibrium between an anion exchange membrane and solutions of electrolytes containing the most dominant anions of natural waters (CI−, NO− 3 and SO2minus; 4) was studied. All experiments were carried out at 0.3 mol l−1. AMX membrane experimented in this work is a commercial product provided by TOKUYAMA SODA. Humidity percentage and ion exchange capacity were determined. Ionic exchange isotherms for the binary systems (CI−/NO−)3,(CI−/SO2− 4) and (NO− 3 / SO2− 4) were established at different temperatures from 283 to 313 K. At 283 and 298 K, the affinity order was: CI− > NO− 3 > SO2− 4. This order was NO− 3 > CI− > SO2− 4 at 313 K. Selectivity coefficients Kj i and thermodynamic equilibrium constants K0j i calculated for uni-univalent and uni-bivalent ions exchange reaction system increase with increasing temperature. Thermodynamic parameters such as standard free enthalpy change, standard enthalpy change, and standard entropy change were calculated....