Radioanalytical Technique Research Articles

Evaluation of the ecological risks on green macro-algae spp. (Ulva fusciata) at the north western coast of Egypt, using neutron activation technique

The study used the radio-analytical technique (Neutron Activation Analysis), besides the other advanced chemical technique, which was inductively coupled plasma mass spectroscopy (ICP-MS), in order to evaluate the bioaccumulation factor (BF), of different trace elements inside the collected green macro algal samples. The results showed that BF results were based on the algal selectivity of each analyzed trace element. The study recommended the using of Ulva fasciata, as a bio-filter of nuclear cooling water system (mitigation tool), due to its selective absorption ability for certain trace elements such as; Th, Cs &Sr.

Application of radio-analytical technique for determination of “Age” of nuclear materials for nuclear forensics

Determination of “Age” – the time elapsed since the last chemical purification – of a nuclear material is an important parameter in Nuclear Forensic analysis. Estimation of age may give crucial acumen of the possible production facility and the declared origin – if available – in case of a suspected nuclear material which is out of regulatory control. Mass spectrometry is the most common analytical technique used for chronological studies due to its superior precision (lower uncertainty). Though alpha spectrometry can be used for age determination, it better suits for irradiated fuel based radio-chronology because of higher specific activity of irradiated actinides (actinides formed by irradiation of actinides within a reactor) like plutonium. This paper describes the application of alpha spectrometry for the age determination in some natural U-metal samples with known history. The method utilises the radioactive non-equilibrium existing between 234U and 230Th isotopes in the sample for the elucidation of age of the material. Optimisation of a chemical procedure for the separation of ultra-trace amount of thorium isotopes from bulk uranium material using double column anion exchange chromatography is also presented. The chemical recoveries of uranium and thorium obtained with the present method were >95%. The uncertainty in age determination was <10% and ∼15% for older (∼51 years) and newer (∼11 years) samples respectively. The method is also used to elucidate the age of an unknown uranium material and found to be 39 ± 4 years old.

Application of radio analytical tracer technique to study the performance of industrial grade ion exchange resin exposed to UV radiations

Abstract The thermodynamics and kinetics of bromide ion-isotopic exchange reactions performed by using fresh and UV radiation degraded industrial grade anion exchange resin Duolite A-638 resins were studied by application of radio analytical tracer technique. The reaction rate k in min−1 for the fresh resin decreases sharply with decrease in wavelength of UV radiations. Thus for 0.200 M labeled bromide ion solution maintained at a constant temperature of 30.0 °C, the k value for fresh resin (0.367 min−1), decreases to 0.335 min−1 for λ384 UV radiation degraded resin, which further decreases to 0.273 min−1 for λ284 UV radiation degraded resin. Under identical experimental conditions, the thermodynamic parameters like energy of activation (−1.65 kJ/mol), enthalpy of activation (−4.24 kJ/mol), free energy of activation (64.85 kJ/mol), and entropy of activation (−0.229 kJ/K/mol) calculated for the fresh resin increases to −1.61 kJ/mol, −4.19 kJ/mol, 64.92 kJ/mol, and −0.228 kJ/K/mol respectively for λ384 UV radiation degraded resin; which further increases to −1.60 kJ/mol, −4.18 kJ/mol, 65.17 kJ/mol, and −0.228 kJ/K/mol respectively for λ284 UV radiation degraded resin. Increase in thermodynamic parameters calculated here for the fresh and degraded resins suggests that decrease in wavelength of UV radiations has catastrophic effect on the resin making the bromide ion-isotopic exchange reactions thermodynamically less feasible. The impact of UV radiation on resin degradation was supported by their characterization study using Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) techniques.

Determination of spectrum shaping factor in nuclear reactor AHWR-CF by Monte Carlo method for material characterization using neutrons

Activation analysis is a well-known radio-analytical technique to carry out the material characterization using neutrons. In this, the sample of material is irradiated in an ambient neutron flux and the induced radioactivity is studied to infer the composition of material. K0 based neutron activation analysis (k0-NAA) is a method used for characterising variety of materials using neutrons. Knowledge of neutron energy spectrum and it’s shaping factor (α) at neutron irradiation location is essential for application of (k0-NAA) method. The objective of the present work is to determine α at central location in AHWR-Critical Facility, a nuclear reactor at Bhabha Atomic Research Center, Mumbai, India. The determination of α was carried out by various analytical methods. The basic inputs required for determination of α were produced by modelling the reactor using in-house developed Monte Carlo code PATMOC. The results were cross checked by generating neutron energy spectrum in the reactor.

Development of rapid solvent extraction based radioanalytical technique for estimation of 90Sr in the presence of natural and anthropogenic radionuclides

A radiochemical technique for estimation of 90Sr concentration by direct extraction of 90Y with bis (2-ethylhexyl) phosphate (HDEHP) in toluene was developed and standardized. About 90% 90Sr retained in the aqueous phase at the optimized pH 4–4.5. Cerenkov counting with 0.04 g mL−1 sodium salicylate as a wavelength shifter resulted in 7.5 fold increase its Cerenkov counting efficiency. The method was validated by estimating 90Sr in certified reference materials like, IAEA TEL 2016-03 drinking water, Spruce needle and IAEA-156 Clover. The interference of naturally occurring Ra and its β progeny especially Pb was eliminated by means of Cerenkov counting. Conventional radiochemical separation was used to compare 90Sr activity in effluent samples.

A rapid method for estimation of Pu-isotopes in urine samples using high volume centrifuge

The conventional radio-analytical technique used for estimation of Pu-isotopes in urine samples involves anion exchange/TEVA column separation followed by alpha spectrometry. This sequence of analysis consumes nearly 3–4 days for completion. Many a times excreta analysis results are required urgently, particularly under repeat and incidental/emergency situations. Therefore, there is need to reduce the analysis time for the estimation of Pu-isotopes in bioassay samples. This paper gives the details of standardization of a rapid method for estimation of Pu-isotopes in urine samples using multi-purpose centrifuge, TEVA resin followed by alpha spectrometry. The rapid method involves oxidation of urine samples, co-precipitation of plutonium along with calcium phosphate followed by sample preparation using high volume centrifuge and separation of Pu using TEVA resin. Pu-fraction was electrodeposited and activity estimated using 236Pu tracer recovery by alpha spectrometry. Ten routine urine samples of radiation workers were analyzed and consistent radiochemical tracer recovery was obtained in the range 47–88% with a mean and standard deviation of 64.4% and 11.3% respectively. With this newly standardized technique, the whole analytical procedure is completed within 9h (one working day hour).

Gastroretentive Sustained Release Floating and Swellable Cefadroxil Formulation: In vitro and in vivo Evaluation

A new Gastroretentive Sustained Release (GRSR) tablet of cefadroxil was developed with floating and swellable properties. Various release retarding polymers, swelling agent, gas generating agent and release modifying agents were evaluated. The optimized formulation was studied for various physical parameters, in vitro drug release profile and for in vitro floating properties. The formulation provided sustained drug release for about 14 h with the floating lag time of 30 s and floating duration of about 14 h. Owing to the promising in vitro floating property, the formulation was explored for in vivo floating performance in healthy human volunteers by radio-analytical technique. The developed formulation of Cefadroxil showed prolonged gastric retention in vivo for 7 h. The tablets also showed significant swelling property with excellent tablet integrity till 7 h. The developed formulation exhibited promising gastroretention in vivo. The radio-analytical technique used to evaluate the in vivo gastroretention was found to be simple, cost-effective and was precisely used for detecting floating time and tablet integrity throughout the study.

Evaluation of anion exchange resins Tulsion A-30 and Indion-930A by application of radioanalytical technique

Radioanalytical technique using 131I and 82Br was employed to evaluate organic based anion exchange resins Tulsion A-30 and Indion-930A. The evaluation was based on performance of these resins during iodide and bromide ion-isotopic exchange reactions. It was observed that for iodide ion-isotopic exchange reaction by using Tulsion A-30 resin, the values of specific reaction rate (min−1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and logKd were 0.238, 0.477, 0.114, and 11.0, respectively, which was higher than 0.155, 0.360, 0.056, and 7.3, respectively as that obtained by using Indion-930A resins under identical experimental conditions of 40.0°C, 1.000 g of ion exchange resins and 0.003 M labeled iodide ion solution. Also at a constant temperature of 40.0°C, as the concentration of labeled iodide ion solution increases 0.001 to 0.004 M, for Tulsion A-30 resins the percentage of iodide ions exchanged increases from 59.0 to 65.1%, and from 46.4 to 48.8% for Indion-930A resins under identical experimental conditions. The identical trend was observed for both the resins during bromide ion-isotopic exchange reactions. The overall results indicate that under identical experimental conditions, Tulsion A-30 show superior performance over Indion-930A resins. The results of present experimental work have demonstrated that the radioanalytical technique used here can be successfully applied for characterization of different ion exchange resins so as to evaluate their performance under various process parameters.

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 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.

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.

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.

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.

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.

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.

Performance Based Characterization of Nuclear and Non-Nuclear Grade Anion Exchange Resins Indion 102 and Indion-860 by Application of Radio Analytical Technique

Performance Based Characterization of Nuclear and Non-Nuclear Grade Anion Exchange Resins Indion 102 and Indion-860 by Application of Radio Analytical Technique The present study deals with the application of 131 I and 82 Br radioactive tracer isotopes to evaluate the performance of Indion-102 (nuclear grade) and Indion-860 (non-nuclear grade) ion exchange resins. The major parameters studied for evaluation were specific reaction rate (min-1 ), percentage and amount of ions exchanged (mmol). It was observed that for both the resins under identical experimental conditions, iodide ions exchange take place at faster rate as compared to that of bromide ions which was related to the extent of solvation. It was observed that at a constant temperature of 35.0 °C, as the concentration of spiked iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 63.8% to 68.8% for Indion-102 resins; while for Indion-860 resins it increases from 51.1% to 52.6%. Similarly for 0.002 M spiked iodide ion solution, with rise in temperature from 30.0 °C to 45.0 °C, it is observed that the percentage of iodide ions exchanged decreases from 66.1% to 64.0% using Indion-102 resins; while for Indion-860 resins it decreases from 52.4% to 49.8%. The study reveals that for both the resins there exist a strong linear correlation between amount of ions exchanged and concentration of ionic solution, as well as between amount of ions exchanged and temperature of exchanging medium. In general based on radiotracer applications it was observed that Indion-102 resins show superior performance than Indion-860 resins under identical operational parameters.

Removal of cesium by spherical resorcinol–formaldehyde resin beads: Sorption and kinetic studies

Batch equilibrium studies were conducted at 20 ± 0.5 °C with indigenously synthesized spherical resorcinol–formaldehyde resin beads, using radioanalytical technique, to determine their capacity for sorption of cesium ions from alkaline medium. Equilibrium isotherm studies were carried out, by varying the initial concentrations of cesium from 0.1 to 50 mM. The liquid-to-solid phase ratio of ~100 ml:1 g was maintained for all the sorption experiments. The equilibrium data were fitted to Langmuir and Freundlich isotherm models. It was observed that Freundlich isotherm explains sorption process nicely. The effect of resin size on percentage cesium ion uptake was also investigated, and 20–40 mesh size was found to be the optimum particle size. The cesium sorption capacity of the beads was determined to be ~238 mg/g. The kinetics of the sorption was studied at different initial cesium ion concentrations, and the kinetics data were fitted into various kinetics models. The kinetics of the cesium ion sorption was found to be pseudo second-order. The mechanistic steps involved were found to be complex, consisting of both film diffusion and intraparticle diffusion with film diffusion as the rate limiting step.

A provenance study of coffee by photon activation analysis

Photon activation analysis (PAA) is a multi-elemental radioanalytical technique in trace elements analysis with high accuracy and precision. Researchers at the Idaho accelerator center performed PAA analysis on coffee samples from several locations around the world as an initial step in assessing the relationship between trace elements in illicit drugs and the soils in which they were grown. The preliminary results show coffees from different locations have different concentrations of trace elements. In the three cases where we have soil samples, the matrices of elements in the coffee samples are closely related to the matrices of the elements of the local soil samples. The majority of trace elemental content is similar to that of the local soil sample in which the coffee is planted. It may be that coffee assimilates numerous elements from the soil where it is grown in similar ratios as is found in the soil. Thus, it is conceivable that the elemental content could serve as “fingerprint” to trace the origins of the coffee. To verify our analytical results we applied X-ray fluorescence (XRF) methods as well. Our PAA results are consistent with XRF experimental data. The future of tracing the origin of illicit drugs with the PAA technique is promising.

Resorcinol-formaldehyde coated XAD resin beads for removal of cesium ions from radioactive waste: synthesis, sorption and kinetic studies

A novel synthetic method was developed to synthesize resorcinol-formaldehyde (RF) resin in spherical form, of required mesh size, using XAD-4 as template beads. The synthesized RF-coated XAD (RF-XAD) beads were characterized, using different techniques. Suitable size and mechanical stability, along with their spherical shape, make these beads most appropriate for column operation. The efficiency of these beads was evaluated for removal of cesium from alkaline medium, in batch conditions, using a radioanalytical technique. The effect of sodium ion concentration, the initial cesium ion concentration and the contact time were also investigated. It was observed that the Kd value for Cs+ ions decreases with increase in Na+ ion concentration. The equilibrium data were fitted into different isotherm models, and were found to be represented well by the Langmuir isotherm equation, with a monolayer sorption capacity of 287 mg g−1. Kinetic modeling analysis, using pseudo first-order, pseudo second-order and intraparticle diffusion equations, shows that the pseudo second-order equation is the most appropriate model for the description of the sorption of cesium ions onto the RF-XAD beads. The rate constants were determined at different initial concentrations. The process mechanism was found to be complex, consisting of both surface sorption and pore diffusion.