Neptunium Reactivity During Co-Precipitation and Oxidation of Fe(II)/Fe(III) (Oxyhydr)oxides

Show simple item record Roberts, Hannah E. Morris, Katherine Mosselmans, J. Fredrick W. Law, Gareth Shaw, Sam 2019-05-10T11:02:03Z 2019-05-10T11:02:03Z 2019-01-08
dc.identifier.citation Roberts , H E , Morris , K , Mosselmans , J F W , Law , G & Shaw , S 2019 , ' Neptunium Reactivity During Co-Precipitation and Oxidation of Fe(II)/Fe(III) (Oxyhydr)oxides ' , Geosciences , vol. 9 , no. 1 , 27 .
dc.identifier.other PURE: 120855540
dc.identifier.other PURE UUID: a2c5b526-1a3b-48af-915f-52164fa054af
dc.identifier.other Scopus: 85060396666
dc.identifier.other WOS: 000459746300027
dc.identifier.other ORCID: /0000-0002-2320-6330/work/57308374
dc.description.abstract Fe(II) bearing iron (oxyhydr)oxides were directly co-precipitated with Np(V)O2+ under anaerobic conditions to form Np doped magnetite and green rust. These environmentally relevant mineral phases were then characterised using geochemical and spectroscopic analyses. The Np doped mineral phases were then oxidised in air over 224 days with solution chemistry and end-point oxidation solid samples collected for further characterisation. Analysis using chemical extractions and X-ray absorption spectroscopy (XAS) techniques confirmed that Np(V) was initially reduced to Np(IV) during co-precipitation of both magnetite and green rust. Extended X-Ray Absorption Fine Structure (EXAFS) modelling suggested the Np(IV) formed a bidentate binuclear sorption complex to both minerals. Furthermore, following oxidation in air over several months, the sorbed Np(IV) was partially oxidised to Np(V), but very little remobilisation to solution occurred during oxidation. Here, linear combination fitting of the X-Ray Absorption Near Edge Structure (XANES) for the end-point oxidation samples for both mineral phases suggested approximately 50% oxidation to Np(V) had occurred over 7 months of oxidation in air. Both the reduction of Np(V) to Np(IV) and inner sphere sorption in association with iron (oxyhydr)oxides, and the strong retention of Np(IV) and Np(V) species with these phases under robust oxidation conditions, have important implications in understanding the mobility of neptunium in a range of engineered and natural environments. en
dc.format.extent 10
dc.language.iso eng
dc.relation.ispartof Geosciences
dc.rights cc_by
dc.rights.uri info:eu-repo/semantics/openAccess
dc.subject 116 Chemical sciences
dc.subject 1171 Geosciences
dc.title Neptunium Reactivity During Co-Precipitation and Oxidation of Fe(II)/Fe(III) (Oxyhydr)oxides en
dc.type Article
dc.contributor.organization Department of Chemistry
dc.description.reviewstatus Peer reviewed
dc.relation.issn 2076-3263
dc.rights.accesslevel openAccess
dc.type.version publishedVersion

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