Linked Life Data

21553877

Source:http://linkedlifedata.com/resource/pubmed/id/21553877

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2011-5-27
pubmed:abstractText
Soluble Fe(II) can reduce soluble U(VI) at rapid rates and in accordance with thermodynamic predictions. This was established by initially creating acidic aqueous solutions in which the sole oxidants were soluble U(VI) species and the sole reductants were soluble Fe(II) species. The pH of the solution was then increased by stepwise addition of OH(-), thereby increasing the potential for electron transfer from Fe(II) to U(VI). For each new pH value resulting from addition of base, values of ?G for the Fe(II)-mediated reduction of U(VI) were calculated using the computed distribution of U and Fe species and possible half reaction combinations. For initial conditions of pH 2.4 and a molar ratio of Fe(II) to U(VI) of 5:1 (1 mM Fe(II) and 0.2 mM U(VI)), ?G for U(VI) reduction was greater than zero, and U(VI) reduction was not observed. When sufficient OH(-) was added to exceed the computed equilibrium pH of 5.4, ?G for U(VI) reduction was negative and soluble Fe(II) species reacted with U(VI) in a molar ratio of ?2:1. X-ray absorption near-edge structure (XANES) spectroscopy confirmed production of U(IV). A decrease in pH confirmed production of acidity as the reaction advanced. As solution pH decreased to the equilibrium value, the rate of reaction declined, stopping completely at the predicted equilibrium pH. Initiation of the reaction at a higher pH resulted in a higher final ratio of U(IV) to U(VI) at equilibrium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1520-5851
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4718-25
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Reduction of uranium(VI) by soluble iron(II) conforms with thermodynamic predictions.
pubmed:affiliation
Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.