Publication:
Superoxide-mediated Fe(II) formation from organically complexed Fe(III) in coastal waters

dc.contributor.author Fujii, Manabu en_US
dc.contributor.author Ito, H en_US
dc.contributor.author Rose, Andrew en_US
dc.contributor.author Waite, T en_US
dc.contributor.author Omura, T en_US
dc.date.accessioned 2021-11-25T14:13:37Z
dc.date.available 2021-11-25T14:13:37Z
dc.date.issued 2008 en_US
dc.description.abstract Fe(III) complexed by organic ligands (Fe(III)L) is the primary form of dissolved Fe in marine and coastal environments. Superoxide, typically produced in biological and photochemical processes, is one of the reducing agents that contributes to transformation of Fe(III)L to bioavailable, free dissolved Fe(II) (Fe(II)`). In this work, the kinetics of superoxide-mediated Fe(Il)` formation from Fe(III)L in a simulated coastal water system were investigated and a comprehensive kinetic model was developed using citrate and fulvic acid as exemplar Fe-binding ligands. To simulate a coastal environment in laboratory experiments, Fe(III)L samples with various ligand/Fe ratios were incubated for 5 min to 1 week in seawater medium. At each ratio and incubation time, the rate Of superoxide-mediated Fe(II)` formation was determined in the presence of the strong Fe(II) binding ligand ferrozine by spectrophotometrically measuring the ferrous-ferrozine complex generated at a constant concentration of superoxide. The Fe(II)` formation rate generally decreased with incubation time, as Fe(III)L gradually dissociated to form less reactive Fe(III) oxyhydroxide. However, when the ligand/Fe ratio was sufficiently high, the dissociation of Fe(III)L (and subsequent Fe precipitation) was suppressed and Fe(II)` was formed at a higher rate. The rate of Fe(III)` produced during the experiment was explained by the kinetic model. The model confirmed that both the ligand/Fe ratio and incubation time have a significant effect on the pathway via which Fe(II)` is formed from Fe(III)-fulvic acid complexes. (c) 2008 Elsevier Ltd. All rights reserved. en_US
dc.identifier.issn 0016-7037 en_US
dc.identifier.uri http://hdl.handle.net/1959.4/42251
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri https://creativecommons.org/licenses/by-nc-nd/3.0/au/ en_US
dc.source Legacy MARC en_US
dc.title Superoxide-mediated Fe(II) formation from organically complexed Fe(III) in coastal waters en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.accessRights.uri http://purl.org/coar/access_right/c_14cb
unsw.relation.faculty Engineering
unsw.relation.ispartofissue 24 en_US
unsw.relation.ispartofjournal Geochimica et Cosmochimica Acta en_US
unsw.relation.ispartofpagefrompageto 6079-6089 en_US
unsw.relation.ispartofvolume 72 en_US
unsw.relation.originalPublicationAffiliation Fujii, Manabu, Civil & Environmental Engineering, Faculty of Engineering, UNSW en_US
unsw.relation.originalPublicationAffiliation Ito, H en_US
unsw.relation.originalPublicationAffiliation Rose, Andrew, Civil & Environmental Engineering, Faculty of Engineering, UNSW en_US
unsw.relation.originalPublicationAffiliation Waite, T, Civil & Environmental Engineering, Faculty of Engineering, UNSW en_US
unsw.relation.originalPublicationAffiliation Omura, T en_US
unsw.relation.school School of Civil and Environmental Engineering *
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