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Sodium-copper hexacyanoferrate (NaCuHCF)-functionalized magnetic nanoadsorbents were fabricated for the highly efficient magnetic removal of radioactive caesium from seawater. The magnetic nanoclusters (MNCs), composed of many individual Fe 3 O 4 nanoparticles, were covalently coated with polyethyleneimine (PEI) to functionalize the MNC surfaces with NaCuHCF. After simple immobilization of Cu and Na ferrocyanide on the NC surface, the resulting NaCuHCF-functionalized MNCs showed good magnetic properties and a significant adsorption capacity for Cs + with a high content of NaCuHCF (36.04%). The adsorption kinetics and isotherms were well fit to a pseudo-second-order model and Langmuir isotherm, respectively. The sorption of 97.35% Cs by the NaCuHCF-PEI-MNCs completed in less than 5 min, and the maximum adsorption capacity of the adsorbent was 166.67 mg/g. The NaCuHCF-PEI-MNCs selectively adsorbed Cs even in the presence of various competing ions, such as Na, K, Mg, and Ca, and the Cs removal mechanism was revealed as ion exchange between Cs in solution and Na in the NaCuHCF-PEI-MNCs. In radioactive tests, our adsorbent displayed excellent removal performance in real seawater with a high removal efficiency exceeding 99.73%, a decontamination factor exceeding 372, and a high stability in water over a wide pH range from 4 to 10 with negligible leaching of Fe., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A novel mesoporous silica-coated ferrocyanide (MSCFC) composite was successfully synthesized and evaluated as a dual-function material for simultaneous removal of (137)Cs(+) cations and (99)TcO4(-) anions from aqueous solutions. Sorption behavior of both radionuclides on MSCFC under different experimental conditions has been studied using a batch technique. Results revealed that about 100% of (137)Cs(+) and 97% of (99)TcO4(-) were removed by MSCFC in the pH ranges of 2.2-12.4 and 4.1-9.5, respectively. Sorption kinetic data were analyzed by pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models, while Langmuir and Freundlich models were applied for the sorption isotherms. The maximum sorption capacity of MSCFC for radiocesium was determined and compared with other reported sorbents. Applicability of the coated ferrocyanide for simultaneous removal of (137)Cs(+) and (99)TcO4(-) from low-level liquid radioactive waste (LLLW) was also tested, and the data revealed that 99.91% and 98.34% were removed from (137)Cs(+) and (99)TcO4(-), respectively. It is concluded that MSCFC exhibits excellent efficiency for simultaneous removal of the mixed radionuclides with different charge from LLLW., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

This paper described the utility of tetragonal nano-zirconia (t-ZrO₂) to remove trace levels of ¹³⁴Cs and ¹³⁷Cs contaminants from ¹²⁵I solution obtained from neutron irradiation of natural Xe target. A careful scrutiny of the adsorption parameters of t-ZrO₂ was considered worthwhile investigating to arrive at the optimum conditions to perform the purification as well as concentration of ¹²⁵I solution. The procedure proposed herein provides ¹²⁵I of acceptable purity and radioactive concentration for clinical application. The compatibility of the separated product in the preparation of ¹²⁵I brachytherapy sources was found to be satisfactory., (© 2013 Elsevier Ltd. All rights reserved.)

Removal behaviour of rice hulls was assessed for the removal of Cs-134 from aqueous solutions. Results obtained from batch-type experiments revealed that relatively low uptake of Cs(I) was favoured with increasing the sorptive concentration (from 1 x 10(-8) to 1 x 10(-2) molL(-1)), temperature (298-328), and pH (2.40-10.20). The concentration dependence data fitted well for Freundlich adsorption isotherm. Thermodynamic parameters revealed that the uptake process was endothermic and proceeded via 'ion exchange' along with 'surface complexation'. Moreover, the adsorbed species were not to be desorbed into the bulk concentration even at elevated temperatures, i.e., up to 328 K hence forming a stable adsorption phase. Further, the radiation stability of the rice hulls samples was also assessed by exposing it towards 300 mCi neutron source having the neutron flux of ca. 3.85 x 10(6) ncm(-2)s(-1) associated with nominal gamma-dose of ca. 1.72 Gyh(-1) and indeed it was observed that the rice hulls samples were found to be stable at least for the removal of Cs-134.

A major limitation on the supply of the short-lived medical isotope 90Y (t1/2 = 64 h) is the available quantity of highly purified 90Sr generator material. A radiochemical production campaign was therefore undertaken to purify 1,500 Ci of 90Sr that had been isolated from fission waste materials. A series of alkaline precipitation steps removed all detectable traces of 137Cs, alpha emitters, and uranium and transuranic elements. Technical obstacles such as the buildup of gas pressure generated upon mixing large quantities of acid with solid 90Sr carbonate were overcome through safety features incorporated into the custom-built equipment used for 90Sr purification. Methods are described for analyzing the chemical and radiochemical purity of the final product and for accurately determining by gravimetry the quantities of 90Sr immobilized on stainless steel filters for future use.

Three different samples of Iranian natural zeolites (clinoptilolite) and its sodium exchanged forms have been investigated for uptaking several different cations. Ion-exchange isotherms, have been given and discussed.