dc.contributor.author
Ring, Simon J.
dc.contributor.author
Henehan, Michael J.
dc.contributor.author
Blukis, Roberts
dc.contributor.author
Blanckenburg, Friedhelm von
dc.date.accessioned
2025-02-11T08:01:58Z
dc.date.available
2025-02-11T08:01:58Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/46555
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-46269
dc.description.abstract
Reversible adsorption and isotope fractionation of boron on the surface of clay minerals is a key process that impacts boron isotope cycling in porewater, rivers and the ocean. However, the differences in boron isotope fractionation factors between various clay minerals and their dependence on fluid chemistry are not well known. We performed two sets of experiments, using solutions of pure water with added boron and seawater, to explore the isotope behavior during adsorption of boron onto kaolinite, smectite and illite. We found that the amount of sorbed boron increases with ionic strength of solutions and is proportional to the cation exchange capacity of a given clay mineral. Maximum adsorption is observed in alkaline seawater, which we attribute to the efficient fixation of magnesium-borate ion pairs onto negatively charged surface sites. Isotopic fractionation is modestly different between clays and demonstrates that clay surfaces preferentially sorb borate, even when the concentration of borate in solution is low. In both pure water and seawater, adsorbed complexes retain the isotopic composition of their dissolved precursors (borate or boric acid) with minimal isotopic fractionation. In other words, isotopic composition of adsorbed boron is set by the ability of clays to adsorb boron from an already fractionated boron pool rather than specific fractionation associated with the complexation reaction. Our experimental results allow us to provide revised constraints on the adsorbed boron being transported in terrestrial fluids and the ocean.
en
dc.format.extent
10 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
Boron isotopes
en
dc.subject
Surface complexation model
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften
dc.title
Adsorption pathways of boron on clay and their implications for boron cycling on land and in the ocean
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1016/j.gca.2024.08.014
dcterms.bibliographicCitation.journaltitle
Geochimica et Cosmochimica Acta
dcterms.bibliographicCitation.pagestart
74
dcterms.bibliographicCitation.pageend
83
dcterms.bibliographicCitation.volume
389
dcterms.bibliographicCitation.url
https://doi.org/10.1016/j.gca.2024.08.014
refubium.affiliation
Geowissenschaften
refubium.affiliation.other
Institut für Geologische Wissenschaften / Fachrichtung Geochemie, Hydrogeologie, Mineralogie

refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
1872-9533
refubium.resourceType.provider
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