Affiliation:
1. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences
2. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences
3. National Research University Higher School of Economics
Abstract
The sorption properties of amorphous cerium(IV) hydrogen phosphate and crystalline phases NH4Ce2(PO4)3, (NH4)2Ce(PO4)2·H2O, and Ce(OH)PO4 towards the 243Am(III), 232Th(IV), 237Np(V), and 233, 238U(VI) radionuclides were studied in aqueous media at pH 1, 4, 7, and 10 for 24 h. The highest degree of sorption (up to 100%) was found for amorphous cerium(IV) hydrogen phosphate. The pH dependences of radionuclide sorption for crystalline compounds were shown to be similar to one another: the highest sorption was observed at pH 7 (up to 100% for 243Am(III)), while the lowest values were observed for pH 10 and 1. An exception was provided by 237Np(V), the sorption of which was close to zero in the pH range of 1–7 and reached 60% at pH 10. Keeping amorphous and crystalline cerium(IV) phosphates in acid medium leads to quantitative desorption of all of the tested radionuclides within the first 5 h.
Publisher
The Russian Academy of Sciences