Speciation of Uranium in Sediments before and after In situ Biostimulation


Autoria(s): Kelly, Shelly D.; Kemner, Kenneth M.; Carley, Jack; Criddle, Craig; Jardine, Phillip M.; Marsh, Terence L.; Phillips, Debra; Watson, David; Wu, Wei-Min
Data(s)

25/01/2008

Resumo

The success of sequestration-based remediation strategies will depend on detailed information, including the predominant U species present as sources before biostimulation and the products produced during and after in situ biostimulation. We used X-ray absorption spectroscopy to determine the valence state and chemical speciation of U in sediment samples collected at a variety of depths through the contaminant plume at the Field Research Center at Oak Ridge, TN, before and after approximately 400 days of in situ biostimulation, as well as in duplicate bioreduced sediments after 363 days of resting conditions. The results indicate that U(VI) in subsurface sediments was partially reduced to 10–40% U(IV) during biostimulation. After biostimulation, U was no longer bound to carbon ligands and was adsorbed to Fe/Mn minerals. Reduction of U(VI) to U(IV) continued in sediment samples stored under anaerobic condition at <4 °C for 12 months, with the fraction of U(IV) in sediments more than doubling and U concentrations in the aqueous phase decreasing from 0.5-0.74 to <0.1 µM. A shift of uranyl species from uranyl bound to phosphorus ligands to uranyl bound to carbon ligands and the formation of nanoparticulate uraninite occurred in the sediment samples during storage.

Identificador

http://pure.qub.ac.uk/portal/en/publications/speciation-of-uranium-in-sediments-before-and-after-in-situ-biostimulation(168c4f21-73f6-4c0a-9217-7bba4d0870c3).html

http://dx.doi.org/10.1021/es071764i

http://www.scopus.com/inward/record.url?scp=40949125662&partnerID=8YFLogxK

Idioma(s)

eng

Direitos

info:eu-repo/semantics/restrictedAccess

Fonte

Kelly , S D , Kemner , K M , Carley , J , Criddle , C , Jardine , P M , Marsh , T L , Phillips , D , Watson , D & Wu , W-M 2008 , ' Speciation of Uranium in Sediments before and after In situ Biostimulation ' Environmental Science and Technology , vol 42 , no. 5 , pp. 1558-1564 . DOI: 10.1021/es071764i

Palavras-Chave #/dk/atira/pure/subjectarea/asjc/2300/2305 #Environmental Engineering #/dk/atira/pure/subjectarea/asjc/2300 #Environmental Science(all) #/dk/atira/pure/subjectarea/asjc/2300/2304 #Environmental Chemistry
Tipo

article