Studies on Ion Exchange Resins. XI. Activity Coefficients of Diffusible Ions in a Strong Base Anion-exchange Resin

1954 ◽  
Vol 76 (18) ◽  
pp. 4639-4641 ◽  
Author(s):  
Melvin H. Gottlieb ◽  
Harry P. Gregor
Author(s):  
Sayan E. Salmenbayev ◽  
◽  
Nazgul K. Nurgaysinova ◽  
Gani M. Yessilkanov ◽  
Аray E. Temirzhanova ◽  
...  

The relevance of the research is caused by the need to develop a methodological base for determining 151Sm content in the soil cover of radioactively contaminated territories of Kazakhstan. The developed method for the determining of 151Sm will make it possible to assess the levels of soil contamination with this radionuclide, to determine the character of its spatial distribution, to allow estimating the internal exposure doses for the personnel and the population. The aim of the research is to carry out the isolation and radiochemical purification of samarium isotopes from acid solutions via using ion-exchange resins AV 17×8 and KU-2. Objects: salt solutions based on nitric and hydrochloric acid containing the stable isotopes of some natural, artificial β-emitters and isotopes of U and Th. The concentrations of nitric and hydrochloric acids were equal to the concentrations of the same acids used in the routine analysis of Pu and Am. Concentrations of chemical elements were determined using the Agilent 7700x quadrupole mass spectrometer and the iCAP 6300 Duo atomic emission spectrometer. The results of the experiments on the isolation and radiochemical purification of samarium isotopes from acidic solutions using anion-exchange resin AV 17×8 and cation-exchange resin KU-2 have been presented. It has been shown that the Sm-fraction can be purified from alkaline elements, Tl and U isotopes using the KU-2 cation-exchange resin. In turn, the isotopes U, Fe and Co can be removed using an anion exchange resin in 9M HCl media.


Author(s):  
György Pátzay ◽  
József Dobor ◽  
Emil Csonka ◽  
Gábor Lozsi ◽  
Ferenc Feil

Borate ion exchange capacity of Purolite NRW600 strong base anion resin in hydroxide form and mixed bed NRW600+NRW100 ion exchange was investigated with static experiments. Anion exchange resin was saturated with 0.1–45 g/dm3 concentration boric acid solution in a static mixer at 20, 30, 40 and 50 °C at 150 rpm for 24 hours. Remaining borate content of saturation solutions was deter-mined with ion chromatography and ICP-OES. The amount of fixed borate as borate anions increased with the saturation borate concentration as well as in case of simple anion exchange as in case of mixed bed.Column sorption-elution study was carried out by using strong base anion exchange resins (Purolite NRW600 and Amberlite IRN78). Resins in hydroxide and in chloride forms were saturated in column with 5–40 g/dm3 boric acid solution in excess. The resin was then eluted with 200 cm3 salt free water with 5 cm3/min at 25 °C and then eluted by 1 mol/dm3 sodium-sulfate solution with 5 cm3/min. The effluent was collected and analyzed for borate content by titrimetric method. In chloride form the resin adsorbed and released much less borate. Effective borate and polyborate sorption needs hydroxide ions in resin phase.


2000 ◽  
Vol 88 (12) ◽  
Author(s):  
K. Vaaramaa ◽  
Satu Pulli ◽  
Jukka Lehto

Effects of pH in the range of 5 to 8 and uranium concentration in the range of 0.02 mg/l to 25 mg/l on the removal of uranium with a strong base anion exchange resin (SBA) and a chelating aminophosphonate resin were studied. The results of the batch and column mode experiments clearly showed that the aminophosphonate resin was an efficient exchanger for the removal of uranium at pH values close to 5 and the SBA resin at higher pH values. In the column experiments, where altogether 2000 bed volumes of drinking water simulant were processed with these exchangers, the uptake of uranium was as high as 99.8% by the aminophosphonate resin at pH 5 and 99.7% by the SBA resin at pH 8.


2020 ◽  
Vol 21 (21) ◽  
pp. 7874
Author(s):  
Natalia Pismenskaya ◽  
Veronika Sarapulova ◽  
Anastasia Klevtsova ◽  
Sergey Mikhaylin ◽  
Laurent Bazinet

This study examines the mechanisms of adsorption of anthocyanins from model aqueous solutions at pH values of 3, 6, and 9 by ion-exchange resins making the main component of heterogeneous ion-exchange membranes. This is the first report demonstrating that the pH of the internal solution of a KU-2-8 aromatic cation-exchange resin is 2-3 units lower than the pH of the external bathing anthocyanin-containing solution, and the pH of the internal solution of some anion-exchange resins with an aromatic (AV-17-8, AV-17-2P) or aliphatic (EDE-10P) matrix is 2–4 units higher than the pH of the external solution. This pH shift is caused by the Donnan exclusion of hydroxyl ions (in the KU-2-8 resin) or protons (in the AV-17-8, AV-17-2P, and EDE-10P resins). The most significant pH shift is observed for the EDE-10P resin, which has the highest ion-exchange capacity causing the highest Donnan exclusion. Due to the pH shift, the electric charge of anthocyanin inside an ion-exchange resin differs from its charge in the external solution. At pH 6, the external solution contains uncharged anthocyanin molecules. However, in the AV-17-8 and AV-17-2P resins, the anthocyanins are present as singly charged anions, while in the EDE-10P resin, they are in the form of doubly charged anions. Due to the electrostatic interactions of these anions with the positively charged fixed groups of anion-exchange resins, the adsorption capacities of AV-17-8, AV-17-2P, and EDE-10P were higher than expected. It was established that the electrostatic interactions of anthocyanins with the charged fixed groups increase the adsorption capacity of the aromatic resin by a factor of 1.8–2.5 compared to the adsorption caused by the π–π (stacking) interactions. These results provide new insights into the fouling mechanism of ion-exchange materials by polyphenols; they can help develop strategies for membrane cleaning and for extracting anthocyanins from juices and wine using ion-exchange resins and membranes.


2014 ◽  
Vol 997 ◽  
pp. 363-367
Author(s):  
Guang Sheng Huo ◽  
Qiong Song ◽  
Chun Hua Liao

A solution containing tungsten and molybdenum was acidified using hydrochloric acid, and the ability of several commercial ion exchange resins to separate tungsten and molybdenum was evaluated. The results from the acidification test indicate that when the pH of the solution is adjusted to 7.0, WO42- is polymerized into HW6O215-, while MoO42- is not. The test results of resins selection show that the D213 resin and the D308 resin are superior to other resins in separating low concentrations of tungsten and molybdenum, whereas the D201 resin and the D309 resin are suitable for separating high concentrations of tungsten and molybdenum. The results from the column test indicate that weak-base anion exchange resins are better than strong-base anion exchange resins for both low and high concentrations of tungsten and molybdenum.


1969 ◽  
Vol 39 (4) ◽  
pp. 184-189
Author(s):  
R. Santini, Jr. ◽  
J. Nevarez

The acerola is considered to be the best natural source of ascorbic acid, it yields from two to four crops during the year, and the ascorbic acid is found dissolved in the juice. Therefore, a method which was used previously for separating and crystallizing the ascorbic acid present in the green walnut hulls, but which could not be applied commercially thereto, has been modified and applied to the acerola. The method involved the use of ion-exchange resins. A cation-exchange resin was used to lower the pH below 2 and an anion-exchange resin to absorb the ascorbic acid. This acid was eluted from an anion-exchange column with a dilute hydrochloric acid Solution. On a laboratory scale the yields obtained were relatively high and in a continuous commercial process the yield should be about 88 percent.


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