Formation of plutonium(iv) silicate species in very alkaline reactive media. Issue 36 (19th August 2021)

• Record Type: Journal Article
• Authors: Estevenon, Paul; Dumas, Thomas; Solari, Pier Lorenzo; Welcomme, Eleonore; Szenknect, Stephanie; Mesbah, Adel; Kvashnina, Kristina O.; Moisy, Philippe; Poinssot, Christophe; Dacheux, Nicolas
• Is Part Of: Dalton transactions. Volume 50:Issue 36(2021)
• Page Start: 12528
• Page End: 12536
• Publication Date: 2021-08-19
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt02248b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Thanks to XAS, sequential filtration and α spectrometry, formation of Pu(iv ) silicate colloids of 6 nm in size was evidenced for pH > 13 and Pu concentration of 10 mM. These species could affect the plutonium mobility under environmental conditions. Abstract : Studying the speciation of Pu(iv ) in very alkaline and silicate ion rich reactive media allowed identification of the formation of plutonium(iv )-silicate colloidal suspensions which were stable for months. These colloids were stabilized in aqueous solution for pH > 13 and for concentrations around 10 −2 mol L −1 . Successive filtration processes allowed evaluation of their size, which was found to be smaller than 6 nm. Their structural characterization by XAS evidenced that their structure was similar to those identified for the other tetravalent actinide-silicate colloidal systems like thorium, uranium and neptunium. Their formation could explain the increase of plutonium solubility usually observed in alkaline silicate-rich solutions and could affect the plutonium mobility as a result in contaminated sites or in other environmental permeable media.