Strontium, removal of cesium and

Microporous titanosilicate compounds have received significant consideration as ion exchangers ever since the introduction of ETS-4 and ETS-10 materials in 1989 [91,97-100], Some of these titanosilicates have proven to be good ion exchangers in neutral and alkaline solutions. For example, a potassium titanosilicate analogue of the mineral pharmacosiderite has been evaluated for the removal of cesium and strontium from various aqueous waste streams [91,101,102],... 

PAN-KCoFC and PAN-4A composite adsorbents were prepared for the removal of cesium and strontium ions from acidic nuclear waste solutions. High porous spheri( composite adsorbents could be prepared using a dual nozzle technique. The acid and radiation stability tests showed that the both composite adsorbents were stable against acid solutions higher than pH - 2 and radiation dose less than 1.89 MGy, respectively. Adsorption tests showed that the PAN-KCoFC was selective for cesium ion and the PAN-zeolite 4A was for strontium ions, respectively. The ion exchange equilibrium isotherms were obtained and evaluated for the binary systems. 

Removal of Cesium and Strontium from Fuel Storage Basin Water... 

Rao, S.V.S. et ah. Effective removal of cesium and strontium from radioactive wastes using chemical treatment followed by ultrafiltration, J. Radioanal. Nucl. Chem. 246(2), 413, 2000. 

Offers the only technology that can remove cesium and strontium from alkaline solutions in the presence of competing cations without additional treatment steps. 

The problem of estimating aerosol transport is thus focused on the study of watershed media effects on the transport of substances in solution rather than in insoluble aerosol particles. Thus, sorption by watershed media is a prime factor in determining the hydrologic transport of soluble radioaerosols, such as cesium and strontium. Removal of soluble radioaerosol elements from runoff by formation of insoluble compounds is considered unlikely. 

Todd, T.A., Romanovskiy, V.N., Brewer, K.N. et al. 1999. Development of a universal cobalt dicarbollide solvent for the removal of actinides, cesium and strontium from acidic wastes. Proc ISEC 99, Barcelona, Spain, July 11-16, pp. 1345-1349. 

Herbst, R.S., Law, J.D., Todd, T.A. et al. 2002. Universal solvent extraction (UNEX) flowsheet testing for the removal of cesium, strontium, and actinides elements from radioactive, acidic dissolved waste. Solvent Extr. IonExch. 20 (4—5) 429 445. 

In the next step, which was designed by researchers of the Idaho National Laboratory (INL, Idaho), cesium and strontium are removed from the UREX raffinates. 

Dozol, J.-F., Casas i Garcia, J., and Sastre, A. M. Applications of Crown-Ethers to Cesium and Strontium Removal from Marcoule Reprocessing Concentrate, in New Separation Chemistry Techniques for Radioactive Waste and Other Specific Applications, Cecille, L., Casarci, M., and Pietrelli, L. (Eds.), Elsevier Applied Science, Amsterdam, 1991, pp. 173-185. 

Crown ethers are also used to remove radioactive elements from radioactive waste. For example, radioactive cesium and strontium can be extracted using specialized derivatives of 18-crown-6. 

Laboratory tests have also shown that cesium and strontium in the effluent from the two plant-scale ion-exchange columns (Zeolon-900 and Amberlite-200) can be further removed by the use of an additional Amberlite-200 and Zeolon-900 column in series. Approximately 9000 column volumes (1.6 X 10 gal for 24 ft of resin) of effluent from the first ion-exchange unit can be processed before the radioactivity concentration guide (RCG) controlled area release limit for each radioisotope is reached and before either column would need to be regenerated. 

Among the various applications of natural zeolites in sectors of technical significance, the use in the control and abatement of environmental pollution is gaining increasing interest all over the world. Copious references on this are found in the introductory plenary lectures of the three International Conferences on natural zeolites held in the last years (1-3) Focusing our attention on the wastawaters pollution abatement, it may be observed that not more than two or three zeolites (clinoptilolite, mordenite and phillipsite) have been considered until now for removal of cationic pollutants from waters, and that the recourse to ion exchange processes has been limited to the treatment of few cations, substantially ammonium, cesium and strontium. Lack of data is found for instance in the literature on the use of natural zeolites for the removal of heavy metals (4-5), even if these are common... 

There are many examples of the studies on SLM for nuclear applications in the literature. SLMs were tested for high-level radioactive waste treatment combined with removal of actinides and other fission products from the effluents from nuclear fuel reprocessing plants. The recovery of the species, such as uranium, plutonium, thorium, americium, cerium, europium, strontium, and cesium, was investigated in vari-ons extracting-stripping systems. Selective permeation... 

Researchers claim that lonsiv TIE-96 can remove 99.9% of the plutonium, strontium, and cesium from waste solutions, allowing for wastes to be divided into separate low-level and high-level radioactive waste streams, where they can be safely and efficiently processed for disposal. 

Sylvester, P. and A. Clearfield (1998). Removal of strontium and cesium from simulated Hanford groundwater using inorganic ion exchange materials. Solvent Extraction Ion Exchange. 16, 6, 1527-1539. 

Many inorganic ion exchangers have been studied for the removal of strontium and cesium ions, due to their high selectivity for specific cations, thermal and radiation stabilities [1 S], In spite of those advantages, they have been limted in their extensive applications because of the pressure drop problem in column operation when they are used in microcrystalline or powdered form. To solve this problem, in the case of synthetic zeolites, clay minerals are often used for pelletization, but it still causes dissolution of clay minerals in aqueous solution. 

Riidorff et al. 66, 72, 54) obtained the ammoniates in a pure state by the action of the blue solution of the alkali or alkaline earth metals on graphite. If the metal is in excess a deep blue graphite compound with the structure of stage 1 results. The strontium and barium compounds are violet at low temperatures. After washing with liquid ammonia and removal of the absorbed ammonia in a vacuum at 0°, the composition corresponds approximately to the formula CiaMeCNHsla- The potassium, rubidium, and cesium compounds may also be obtained by treating CgMe with liquid ammonia. 

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