Role of superoxide in the photochemical reduction of iron in seawater Rose, Andrew en_US Waite, T en_US 2021-11-25T14:15:24Z 2021-11-25T14:15:24Z 2006 en_US
dc.description.abstract We have conducted a series of laboratory studies to investigate the generation of ferrous iron and reactive oxygen species when solutions of seawater containing natural organic matter (NOM) and ferric iron are exposed to simulated sunlight. Total ferrous iron and hydrogen peroxide were measured at nanomolar concentrations with high temporal resolution using chemiluminescence-based methods. In all cases, ferrous iron concentrations rapidly peaked at several nanomoles per litre after a few minutes, and then declined over time, while hydrogen peroxide concentrations increased in a non-linear manner. Although concentrations of both species depended on the concentration of NOM, hydrogen peroxide concentrations were only minimally affected by the presence of iron. Increasing the NOM concentration while the total iron concentration was maintained constant led to an increase in the maximum ferrous iron concentration, suggesting that superoxide-mediated reduction of iron may be a major pathway for ferrous iron formation. This was supported by measurements of superoxide production from irradiation of NOM in the absence of iron and kinetic calculations, as well as an experiment in which superoxide dismutase was added. Further analysis of the data suggested that dissolved oxygen and photo-produced hydrogen peroxide were the primary oxidants of the Fe(II) formed. Thus we propose that superoxide and ferrous iron may be intricately coupled in the system, and that their generation is determined by the supply of NOM available to harvest light and donate electrons. © 2006 Elsevier Inc. All rights reserved. en_US
dc.identifier.issn 0016-7037 en_US
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri en_US
dc.source Legacy MARC en_US
dc.subject.other Hydrogen peroxide en_US
dc.subject.other Iron en_US
dc.subject.other Organic matter en_US
dc.subject.other Photochemistry en_US
dc.subject.other Photochemistry en_US
dc.title Role of superoxide in the photochemical reduction of iron in seawater en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.relation.faculty Engineering
unsw.relation.ispartofissue 15 en_US
unsw.relation.ispartofjournal Geochimica et Cosmochimica Acta en_US
unsw.relation.ispartofpagefrompageto 3869-3882 en_US
unsw.relation.ispartofvolume 70 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 School of Civil and Environmental Engineering *
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