Linked Life Data

20039733

Source:http://linkedlifedata.com/resource/pubmed/id/20039733

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-12-30
pubmed:abstractText
The factors controlling rates of contaminant reduction by magnetite (Fe3O4) are poorly understood. Here, we measured the reduction rates of three ArNO2 compounds by magnetite particles ranging from highly oxidized (x = Fe2+/Fe3+ = 0.31) to fully stoichiometric (x = 0.50). Rates of ArNO2 reduction became almost 5 orders of magnitude faster as the particle stoichiometry increased from x = 0.31 to 0.50. To evaluate what was controlling the rate of ArNO2 reduction, we measured apparent 15N kinetic isotope effects ((15)N-AKIE) values for nitrobenzene and magnetite open-circuit potentials (E(OCP)). 15N-AKIE values were greater than unity for all magnetite stoichiometries investigated, indicating that mass transfer processes are not controlling the rate of ArNO2 reduction by magnetite. E(OCP) measurements showed that the E(OCP) for magnetite was linearly related to the stoichiometry, with more stoichiometric magnetite having a lower potential. Based on these results, we propose that conceptual models that incorporate both redox and Fe2+ diffusion processes, rather than those that rely solely on diffusion of Fe2+, are more appropriate for understanding contaminant reduction by magnetite. Our work indicates that particle stoichiometry should be considered when evaluating rates of contaminant reduction by magnetite.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0013-936X
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
55-60
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Redox behavior of magnetite: implications for contaminant reduction.
pubmed:affiliation
Civil and Environmental Engineering, University of Iowa, Iowa City, Iowa 52240, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't