Kinetics of Ion-Isotopic Exchange Reactions using Nuclear Grade Resins Purolite NRW-4000 and Purolite NRW-60

Abstract

Abstract

The paper deals with an application of nondestructive radio isotopic tracer technique in performance evaluation of two nuclear grade anion exchange resins Purolite NRW-4000 and Purolite NRW-6000. The technique was used to study the kinetics of bromide and iodide ion-isotopic exchange reactions taking place between the external ionic solution and the resin surface for which ¹³¹I and ⁸²Br were used as tracer isotopes. It was observe that at a constant temperature of 30°Cwhen the concentration of iodide ions in solution increases from 0.001 to 0.004 mol/L, the specific reaction rate values for iodide ion-isotopic exchange increases from 0.325 to 0.368 min^-1 for Purolite NRW-6000, while in case of Purolite NRW-4000, under identical experimental conditions, the specific reaction rate values increases from 0.268 to 0.315 min^-1. However, when the concentration of iodide ions in solution is kept constant at 0.001 mol/L and temperature is raised from 30 to 45°C, in case of Purolite NRW-6000 the specific reaction rate values for iodide ion-isotopic exchange decreases from 0.325 to 0.310 min^-1, while in case of Purolite NRW-4000, under identical experimental conditions, the specific reaction rate values for iodide ion-isotopic exchange decreases from 0.268 to 0.251 min^-1. Also it was observed that at a constant temperature of 30°C, as the concentration of labeled iodide ion solution increases from 0.001 to 0.004 mol/L, the percentage of iodide ions exchanged increases from 76.40 to 83.32% using Purolite NRW-6000 resins. While under the same experimental conditions using Purolite NRW-4000 resins the percentage of iodide ions exchanged increases from 67.32 to 74.88 %. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate that as compared to Purolite NRW-4000 resins, Purolite NRW-6000 resins shows superior performance under identical experimental conditions.

Keywords:Nuclear grade resins, tracer isotopes, nondestructive technique, ion-isotopic exchange, reaction kinetics, purolite NRW-4000, purolite NRW-6000, ¹³¹I, ⁸²Br