Ion Exchange Rate Research Articles

Spatial and temporal variability of the chemistry of the shallow groundwater in the alluvial fan area of the Luanhe river, North China

Groundwater in the alluvial fan area of the Luanhe river, north China, was monitored every 2 months for a year. Subsequently, the temporal and spatial variability in the hydrochemical characteristics of the water was investigated using hierarchical cluster analysis (HCA) and a trilinear Piper diagram. It is found that the spatial variability in the groundwater composition from different monitoring wells has obvious differences, even if the distance between many of the wells is small. Also, the difference in the ion concentration was found to be up to fivefold for the same monitored well. Research has indicated that the groundwater’s chemical characteristics are mainly controlled by soil type, the amount of precipitation, the Luanhe river, the groundwater, and human factors. The thickness and continuous distribution of clay influences the velocity and ion exchange rate of the groundwater flow. This results in the amount of total dissolved solids in the groundwater increasing from upstream to downstream. In the flood season (June, July, and August), ion concentration gradually decreases as a result of the increased recharging of the groundwater due to precipitation. Classification using HCA indicates that the samples can be clustered into different groups according to correlation coefficients. Also, the chemical composition of the water from monitoring wells near the Luanhe river is approximately consistent with that from the Luanhe river. This implies that the samples have some compositions resulted from the mixing of groundwater and river water. The Piper diagram indicates that Ca2+, Mg2+, and HCO3− ions are the predominant ones present, i.e., the type of groundwater is of the Ca–Mg–HCO3 type.

Radio analytical technique in characterization of nuclear grade ion exchangers Duolite ARA-9366B and Purolite NRW-5010

Ion exchange is one of the widely used techniques in nuclear industries for treatment of liquid radioactive waste. Regular efforts are being made in order to develop new ion exchange resins and their subsequent characterization so as to bring about efficient industrial performance. Among the different characterization techniques, radioactive tracer technique is one of the sensitive analytical techniques, mainly because of its non-destructive nature, high detection sensitivity, capability of in-situ detection, and physico-chemical compatibility with the material under study. The present work was therefore performed to demonstrate the application of the radioactive tracer technique in performance evaluation of two closely related nuclear grade anion exchange resins Duolite ARA-9366B and Purolite NRW-5010. The short-lived radioisotope 131I and 82Br were used in the present experimental work to trace the kinetics of iodide and bromide ion-isotopic exchange reactions. The radioactivity was measured at various time intervals using γ-ray spectrometer having well type NaI(Tl) scintillation detector of Nucleonix make. From the radioactivity measured at various time intervals, the values of specific reaction rate (min−1), amount of ion exchanged (mmol), and initial rate of ion exchange (mmol/min) were calculated. It was observed that for iodide ion-isotopic exchange reaction under identical experimental conditions of 30.0°C, 1.000 g of ion exchange resins and 0.001 mol/L labeled iodide ion solution, the above values were calculated as 0.246, 0.155, and 0.038, respectively for Purolite NRW-5010 resin, which was higher than the respective values of 0.201, 0.139, and 0.028 obtained for Duolite ARA-9366B resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate that under identical experimental conditions, Purolite NRW-5010 resins exhibit superior performance over Duolite ARA-9366B resins. The same technique can be extended further for performance evaluation of different nuclear as well as non-nuclear grade ion exchange resins.

Radiotracers in performance evaluation of nuclear grade resins Amberlite IRN-78 and Purolite NRW-8000

Abstract The present paper deals with evaluation of organic base nuclear grade anion exchange resins Amberlite IRN-78 and Purolite NRW-8000 by application of radioactive tracer isotopes 131I and 82Br. The evaluation was made on the basis of their performance in iodide and bromide ion-isotopic exchange reactions carried out under different experimental conditions like temperature and ionic concentration. It was observed that during iodide ion-isotopic exchange reaction at a constant temperature of 30.0 °C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 70.10 % to 77.10 % for Amberlite IRN-78, which was higher than an increase of 63.90 % to 71.00 % as obtained for Purolite NRW-8000 resins. Also at a constant temperature of 30.0 °C, using 1.000 g of ion exchange resins and 0.001 mol/L labeled iodide ion solution, the values of specific reaction rate (min−1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were calculated to be 0.280, 0.175, 0.049 and 11.4 respectively for Amberlite IRN-78 resin, which was higher than the values of 0.258, 0.160, 0.041 and 10.6 respectively as that obtained by using Purolite NRW-8000 resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The results of present investigation also indicate that during the two ion-isotopic exchange reactions, for both the resins, there exists a strong positive linear correlation between amount of ions exchanged and concentration of ionic solution; and strong negative correlation between amount of ions exchanged and temperature of exchanging medium. The overall results indicate that under identical experimental conditions, Amberlite IRN-78 resins show superior performance over Purolite NRW-8000 resins.

Radiotracers in kinetics of ion-isotopic exchange reactions using anion exchange resins indion-103 and indion-870

The kinetics of iodide and bromide ion-isotopic exchange reactions was studied by radio analytical technique using 131I and 82Br as tracer isotopes. The parameters like specific reaction rate (min−1), amount of ions exchanged (mmol), initial rate of ion exchange (mmol/min) and logK d were studied to evaluate the performance of nuclear and non-nuclear grade anion exchange resins Indion-103 and Indion-870. For iodide ion-isotopic exchange reactions under experimental conditions of 35.0°C, 1.000 g of ion exchange resins and 0.002 M labeled iodide ion solution, the parameters were 0.223 min−1, 0.300 mmol, 0.067 mmol/min and 18.7, respectively, for Indion-103, and those of 0.165 min−1, 0.251 mmol, 0.041 /min and 16.2, respectively, for Indion-870. The similar tendency was observed during bromide ion-isotopic exchange reactions. The results suggest that Indion-103 shows greater performance than Indion-870 resin under similar experimental conditions.

NON DESTRUCTIVE APPLICATION OF RADIOACTIVE TRACER TECHNIQUE FOR CHARACTERIZATION OF INDUSTRIAL GRADE ANION EXCHANGE RESINS INDION GS-300 AND INDION-860

The paper deals with the application of radio isotopic non-destructive technique in the characterization of two industrial grade anion exchange resins Indion GS-300 and Indion-860. For the characterization of the two resins, 131I and 82Br were used as tracer isotopes to trace the kinetics of iodide and bromide ion-isotopic exchange reactions. It was observed that the values of specific reaction rate (min−1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were calculated as 0.328, 0.577, 0.189 and 19.7 respectively for Indion GS-300 resin, which was higher than the respective values of 0.180, 0.386, 0.070 and 17.0 calculated for Indion-860 resins when measured under identical experimental conditions. Also at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 75.16 % to 78.36 % for Indion GS-300 resins, which was higher than the increases from 49.65 % to 52.36 % compared to that obtained for Indion-860 resins. The overall results indicate that under identical experimental conditions, Indion GS-300 resins show superior performance over Indion-860 resins.

Electrochemical properties of poly(3,4-ethylenedioxythiophene) grown on Pt(111) in imidazolium ionic liquids

Poly(3,4-ethylenedioxythiophene) (PEDOT) was galvanostatically synthesized and studied on a Pt(111) electrode in the following ionic liquids: 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf2]), 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([Emmim][NTf2]), 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim][OTf]) and 1-butyl-2,3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmmim][NTf2]) by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The thin films prepared with this method and cycled in these ionic liquids show high n-doping currents and high rates of ion exchange during redox switching compared to those obtained in molecular solvents.

Radiotracers in Study of Anion Exchange Resins Purolite NRW-8000 and Duolite A-171

Radiotracers in Study of Anion Exchange Resins Purolite NRW-8000 and Duolite A-171 Radioactive tracers 131I and 82Br were used to understand the performance of anion exchange resins Purolite NRW-8000 and Duolite A-171. The ion exchangers were separately brought in equilibrium with labeled I- and Br- ions solutions in the concentrations range of 0.001 to 0.004 mol/L and temperature varying from 30.0 to 45.0°C to study the I- and Br- ion-isotopic exchange reactions. The results show that under similar experimental conditions, the values of specific reaction rate in min-1, amount of ion exchanged in mmol and initial rate of ion exchange in mmol/min were lower for Br- ion-isotopic exchange reaction as compared to that for Iion- isotopic exchange reaction. Also for both the reactions, under similar conditions, the specific reaction rate values rises with rise in concentration of ionic solution, and decreases with rise in temperature.

Ion-isotopic exchange reaction kinetics using Duolite ARA-9366B and Indion-AGR resins

Radiotracer isotopic technique as an effective analytical tool was used to study the kinetics of ion-isotopic exchange reactions in the nuclear- and nonnuclear-grade anion exchange resins Duolite ARA-9366B and Indion-AGR. On the basis of kinetic data, specific reaction rate (per minute), amount of ion exchanged (millimoles), initial rate of iodide ion exchange (millimoles per minute), and log Kd values were calculated for the two resins. It was observed that under identical experimental conditions of 35.0 °C, 1.000 g of ion exchange resins, and 0.002 mol/L of labeled iodide ion solution, the values calculated were 0.200 min−1, 0.278 mmol, 0.056 mmol/min, and 9.6, respectively, for Duolite ARA-9366B resin, which were higher than 0.102 min−1, 0.216 mmol, 0.022 mmol/min, and 5.7, respectively, for Indion-AGR resins. An identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate that under identical experimental conditions, Duolite ARA-9366B resins show superior performance than Indion-AGR resins. The results of the present experimental work have demonstrated that the radioanalytical technique used here can be successfully applied for the characterization of different ion exchange resins so as to evaluate their performance under various process parameters.

Effect of Ion Concentration Changes in the Limited Extracellular Spaces on Sarcolemmal Ion Transport and Ca2+ Turnover in a Model of Human Ventricular Cardiomyocyte

We have developed a computer model of human cardiac ventricular myocyte (CVM), including t-tubular and cleft spaces with the aim of evaluating the impact of accumulation-depletion of ions in restricted extracellular spaces on transmembrane ion transport and ionic homeostasis in human CVM. The model was based on available data from human CVMs. Under steady state, the effect of ion concentration changes in extracellular spaces on [Ca2+]i-transient was explored as a function of critical fractions of ion transporters in t-tubular membrane (not documented for human CVM). Depletion of Ca2+ and accumulation of K+ occurring in extracellular spaces slightly affected the transmembrane Ca2+ flux, but not the action potential duration (APD90). The [Ca2+]i-transient was reduced (by 2%–9%), depending on the stimulation frequency, the rate of ion exchange between t-tubules and clefts and fractions of ion-transfer proteins in the t-tubular membrane. Under non-steady state, the responses of the model to changes of stimulation frequency were analyzed. A sudden increase of frequency (1–2.5 Hz) caused a temporal decrease of [Ca2+] in both extracellular spaces, a reduction of [Ca2+]i-transient (by 15%) and APD90 (by 13 ms). The results reveal different effects of activity-related ion concentration changes in human cardiac t-tubules (steady-state effects) and intercellular clefts (transient effects) in the modulation of membrane ion transport and Ca2+ turnover.

An Improved Understanding of Li+ Hopping Pathways and Rates in Li3Fe2(PO4)3 Using Selective Inversion 6Li NMR Spectroscopy

6Li selective inversion NMR experiments are used to reveal Li ion exchange rates and energy barriers for Li ion hopping in monoclinic Li3Fe2(PO4)3. The three crystallographically unique Li sites in this material are well resolved by magic-angle spinning, thus allowing for the examination of all three exchange processes. We have revisited this material using selective inversion to probe dynamics, and energy barriers over the temperature range 268–397 K are found to be 0.37 ± 0.07, 0.53 ± 0.02, and 0.52 ± 0.03 eV for the three unique exchange pairs. The results presented here are consistent with the known Li3Fe2(PO4)3 crystal structure. The selective inversion experiment is more robust than 2D EXSY for the determination of energy barriers by NMR; this can be attributed to the efficiency of the one-dimensional technique, and an exchange model that accounts for multisite exchange and fast spin–lattice relaxation. Moreover, bond valence sum density maps provide a meaningful depiction of lithium ion diffusion p...

Non-destructive radioanalytical technique in characterization of anion exchangers Amberlite IRN78 and Indion H-IP

The present study deals with characterization of industrial grade anion exchange resins Amberlite IRN78 and Indion H-IP for which non-destructive radiotracer technique using 131I and 82Br was used. The radioisotopes were used to trace the kinetics of iodide and bromide ion-isotopic exchange reactions taking place in the two resins. It was observed that under identical experimental conditions of 40.0 °C, 1.000 g of ion exchange resins and 0.003 M labeled iodide ion solution for iodide ion-isotopic exchange reaction, the values of specific reaction rate (min−1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol min−1) and log K d were 0.285, 0.544, 0.155 and 12.6 respectively for Amberlite IRN78 resin, which was higher than 0.093, 0.315, 0.029 and 4.9 respectively as that obtained by using Indion H-IP resins. Also at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases 0.001–0.004 M, the percentage of iodide ions exchanged increases from 68.10 to 74.00 % for Amberlite IRN78 resin, which was higher than the increase of 40.20–42.80 % as observed for Indion H-IP resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate that that under identical experimental conditions Amberlite IRN78 resins shows superior performance over Indion H-IP resins.

Physicochemical characterisation of natural K-clinoptilolite and heavy-metal forms from Gördes (Manisa, western Turkey)

Physicochemical characterisation of natural K-clinoptilolite and heavy-metal (Ag+, Cd2+, Cr3+ and Co3+) forms was accomplished through ion exchange by batch, X-ray diffractometric (XRD), X-ray fluorescence (XRF), infrared-spectral (FT-IR), differential thermal analysis–thermal gravimetric (DTA–TG) and scanning-electron microscopic (SEM) methods. Increasing the normality in the cases of heavy-metal forms resulted in decrease in crystallinity and increases in unit-cell volume, rate of ion exchange, and percentage of ion selectivity. In this study, the order of ion-selectivity percentages (rather than ion selectivity) of heavy-metal forms was determined to be Ag+>Cd2+>Cr3+>Co3+. This finding is consistent with the results of worldwide research on the order of ion selectivity in modified clinoptilolite.

Radio Analytical Nondestructive Technique in Performance Evaluation of Organic Base Ion Exchange Resins Purolite NRW-6000 and Duolite A-378

Nondestructive radioanalytical technique using short lived isotopes 131I and 82Br was used as tracers to study the kinetics of iodide and bromide ion-isotopic exchange reactions. The kinetic data so obtained was used to evaluate the performance of organic base anion exchange resins Purolite NRW-6000 and Duolite A-378. It was observed that for iodide ion-isotopic exchange reaction performed at 40.0 °C using 1.000 g of ion exchange resins and 0.003 mol/L labeled iodide ion solution, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were calculated as 0.332, 0.582, 0.193 and 16.2 respectively for Purolite NRW-6000 resin, which was higher than the respective values of 0.210, 0.421, 0.088 and 14.7 as that obtained for Duolite A-378 resins. Also at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 74.68% to 79.48% using Purolite NRW-6000 resins and from 52.30% to 58.90% using Duolite A-378 resins. The overall results indicate superior performance of Purolite NRW-6000 resins over Duolite A-378 resins under identical operational parameters. It is expected here that the present technique can be extended further for characterization of different ion exchange resins which will further help in the selection of those reins for the specific industrial application.

Application of Nondestructive Radio Tracer Technique in Performance Evaluation of Anion Exchange Resins Duolite ARA-9366 and Duolite A-171

Radio analytical technique as a non-destructive technique was used in the present investigation to trace the kinetics of ion-isotopic exchange reaction taking place in Duolite ARA-9366 (nuclear grade) and Duolite A-171 (non-nuclear grade) anion exchange resins. The kinetics data suggest that during iodide ion-isotopic exchange reactions under identical experimental conditions of 40.00C, 1.000 g of ion exchange resins and 0.003 M labeled iodide ion solution, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were 0.176, 0.383, 0.067 and 7.8 respectively for Duolite ARA-9366 resin, which was higher than 0.142, 0.353, 0.050 and 7.0 respectively as that obtained for Duolite A-171 resins. Also it is observed that at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 49.20% to 51.80% for Duolite ARA-9366 resins; and from 45.20% to 47.80% for Duolite A-171 resins. The similar trend was observed for the two resins during bromide ion-isotopic exchange reactions. The overall results indicate superior performance of Duolite ARA-9366 resins over Duolite A-171 resins under identical operational parameters.

Non Destructive Application of Radioactive Tracer Isotopes for Performance Evaluation of Industrial Grade Anion Exchange Resins Tulsion A-33 and Indion NSSR

The present study deals with non-destructive application of radioactive tracer isotopes to evaluate the performance of Tulsion A-33 (nuclear grade) and Indion NSSR (non-nuclear grade) anion exchange resins. The performance evaluation was done by carrying out the iodide and bromide ion-isotopic exchange reactions using the above resins. It was observed that at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 58.0% to 64.0% for Tulsion A-33 resins; and from 48.4% to 50.8% for Indion NSSR resins. Similarly in case of bromide ion-isotopic exchange reaction under identical experimental conditions, the percentage of bromide ions exchanged increases from 45.6% to 50.4% for Tulsion A-33 resin; and from 39.8% to 44.6% for Indion NSSR resin. It was also observed that during iodide ion-isotopic exchange reaction at 40.0 °C, using 1.000 g of ion exchange resins and 0.003 M labeled ionic solution, using Tulsion A-33 resin the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were 0.229, 0.469, 0.107 and 10.6 respectively, which was higher than the values of 0.167, 0.375, 0.063 and 7.6 respectively as obtained by using Indion NSSR resins under identical experimental conditions. The overall results indicate superior performance of Tulsion A-33 over Indion NSSR resin under identical operational parameters.

Radiotracer Technique in Study of Strongly Basic Anion Exchange Resins Dowex-SBR LC and Indion-454

The present paper demonstrates application of isotopic tracer technique in characterization of anion exchange resins Dowex-SBR LC and Indion-454 for which 131I and 82Br radio isotopes were used. The characterization was made based on iodide and bromide ion-isotopic exchange reaction kinetic data obtained for the two resins. It was observed that during iodide ion-isotopic exchange reaction performed at 35.0 °C, 1.000 g of ion exchange resins and 0.002 mol/L labeled iodide ion solution, the values of specific reaction rate (min-1), amount of ion exchanged (mmol), initial rate of ion exchange (mmol/min) and log Kd were 0.379, 0.426, 0.161 and 16.2 respectively for Dowex-SBR LC resin, which was higher than the respective values of 0.156, 0.243, 0.038 and 13.4 as that obtained by using Indion-454 resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The results of present investigation also indicate that during the two ion-isotopic exchange reactions, for both the resins, there exists a strong positive linear correlation between amount of ions exchanged and concentration of ionic solution; and strong negative correlation between amount of ions exchanged and temperature of exchanging medium. Based on overall results it appears that under identical experimental conditions, as compared to Indion-454 resins, Dowex-SBR LC resins show superior performance. It is expected here that the present technique can be extended further for characterization of different ion exchange resins which will further help in the selection of those reins for the specific industrial application

Nondestructive Radioactive Tracer Technique in Characterization of Anion Exchange Resins Purolite NRW-8000 and Duolite A-368

Radioactive tracer isotopes 131I and 82Br were used to characterize anion exchange resins Purolite NRW-8000 and Duolite A-368 by application of nondestructive technique. The resin characterization was based on their performance during iodide and bromide ion-isotopic exchange reactions. It was observed that during the iodide ion-isotopic exchange reaction at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 62.10% to 68.10 % using Purolite NRW-8000 resins and from 44.20% to 46.80% using Duolite A-368 resins. Also at a constant temperature of 40.0 °C, 1.000 g of ion exchange resins and 0.003 mol/L labeled iodide ion solution, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were calculated as 0.260, 0.500, 0.130 and 11.8 respectively for Purolite NRW-8000 resin, which was higher than the respective values of 0.130, 0.345, 0.045 and 6.7 as that obtained for Duolite A-368 resins. The similar trend was observed for the two resins during bromide ion-isotopic exchange reaction. From the overall results it appears that under identical experimental conditions, Purolite NRW-8000 resins show superior performance over Duolite A-368 resins. It is expected here that the present nondestructive technique can be extended further for characterization of different industrial grade ion exchange resins, which will help in their selection for specific industrial application.

Comparative Study of Anion Exchange Resins Purolite NRW-6000 and Duolite A-143 by Application Isotopic Technique

Isotopic tracer technique using 131I and 82Br was used to characterize Purolite NRW-6000 and Duolite A-143 anion exchange resins. The characterization study was done by carrying out iodide and bromide ion-isotopic exchange reactions taking place between the resin surface and the external labeled ionic solution. For the two resins it was observed that under identical experimental conditions, the values of specific reaction rate (min-1), amount of ion exchanged (mmol) and initial rate of ion exchange (mmol/min) were calculated to be lower for bromide ion-isotopic exchange reaction than that for iodide ion-isotopic exchange reaction. Also during both the ion-isotopic exchange reactions, under identical experimental conditions for the two resins, the values of specific reaction rate increases with increase in ionic concentration and was observed to decrease with rise in temperature. For a constant temperature of 35.0 °C, as the concentration of labeled bromide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of bromide ions exchanged increases from 67.80% to 72.76% using Purolite NRW-6000 resin and from 42.54% to 50.45% using Duolite A-143 resin. However when the temperature was raised from 30.0 °C to 45.0 °C by keeping the concentration of labeled bromide ion solution constant at 0.002 mol/L, the percentage of bromide ions exchanged decreases from 70.68 % to 67.32 % using Purolite NRW-6000 resin and from 47.50% to 42.25% using Duolite A-143 resin. From the results it appears that Purolite NRW-6000 resins show superior performance over Duolite A-143 resins under identical experimental conditions. It is expected that the present isotopic tracer technique can be applied further as an efficient nondestructive technique in characterization of various ion exchange resins so as to bring about their efficient industrial applications.

Radio Analytical Nondestructive Technique in Performance Evaluation of Organic Base Ion Exchange Resins Purolite NRW-6000 and Duolite A-378

Nondestructive radioanalytical technique using short lived isotopes 131I and 82Br was used as tracers to study the kinetics of iodide and bromide ion-isotopic exchange reactions. The kinetic data so obtained was used to evaluate the performance of organic base anion exchange resins Purolite NRW-6000 and Duolite A-378. It was observed that for iodide ion-isotopic exchange reaction performed at 40.0 °C using 1.000 g of ion exchange resins and 0.003 mol/L labeled iodide ion solution, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were calculated as 0.332, 0.582, 0.193 and 16.2 respectively for Purolite NRW-6000 resin, which was higher than the respective values of 0.210, 0.421, 0.088 and 14.7 as that obtained for Duolite A-378 resins. Also at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 74.68% to 79.48% using Purolite NRW-6000 resins and from 52.30% to 58.90% using Duolite A-378 resins. The overall results indicate superior performance of Purolite NRW-6000 resins over Duolite A-378 resins under identical operational parameters. It is expected here that the present technique can be extended further for characterization of different ion exchange resins which will further help in the selection of those reins for the specific industrial application.

Application of Nondestructive Radio Tracer Technique in Performance Evaluation of Anion Exchange Resins Duolite ARA-9366 and Duolite A-171

Radio analytical technique as a non-destructive technique was used in the present investigation to trace the kinetics of ion-isotopic exchange reaction taking place in Duolite ARA-9366 (nuclear grade) and Duolite A-171 (non-nuclear grade) anion exchange resins. The kinetics data suggest that during iodide ion-isotopic exchange reactions under identical experimental conditions of 40.00C, 1.000 g of ion exchange resins and 0.003 M labeled iodide ion solution, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were 0.176, 0.383, 0.067 and 7.8 respectively for Duolite ARA-9366 resin, which was higher than 0.142, 0.353, 0.050 and 7.0 respectively as that obtained for Duolite A-171 resins. Also it is observed that at a constant temperature of 40.0 °C, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 49.20% to 51.80% for Duolite ARA-9366 resins; and from 45.20% to 47.80% for Duolite A-171 resins. The similar trend was observed for the two resins during bromide ion-isotopic exchange reactions. The overall results indicate superior performance of Duolite ARA-9366 resins over Duolite A-171 resins under identical operational parameters.