Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export
In freshwater wetlands, redox interfaces characterized by circumneutral pH, steep gradients in O2, and a continual supply of Fe(II) form ecological niches favorable to microaerophilic iron(II) oxidizing bacteria (FeOB) and the formation of flocs; associations of (a)biotic mineral phases, microorgani...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/529133 2023-05-15T16:47:42+02:00 Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export Thomas Arrigo, Laurel K. Notini de Andrade, Luiza Shuster, Jeremiah Nydegger, Tabea Vontobel, Sophie Fischer, Stefan Kappler, Andreas Kretzschmar, Ruben 2022-04-10 application/application/pdf https://hdl.handle.net/20.500.11850/529133 https://doi.org/10.3929/ethz-b-000529133 en eng Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.scitotenv.2021.151567 info:eu-repo/semantics/altIdentifier/wos/000766811900012 info:eu-repo/grantAgreement/ETHZ/ETH Seeds/SEED-13 18-2 info:eu-repo/grantAgreement/EC/H2020/788009 http://hdl.handle.net/20.500.11850/529133 doi:10.3929/ethz-b-000529133 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY Science of The Total Environment, 816 Freshwater flocs Fe(II)-oxidizing bacteria Biominerals Wetlands EXAFS 57Fe Mössbauer info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2022 ftethz https://doi.org/20.500.11850/529133 https://doi.org/10.3929/ethz-b-000529133 https://doi.org/10.1016/j.scitotenv.2021.151567 2023-02-13T01:13:54Z In freshwater wetlands, redox interfaces characterized by circumneutral pH, steep gradients in O2, and a continual supply of Fe(II) form ecological niches favorable to microaerophilic iron(II) oxidizing bacteria (FeOB) and the formation of flocs; associations of (a)biotic mineral phases, microorganisms, and (microbially-derived) organic matter. On the volcanic island of Iceland, wetlands are replenished with Fe-rich surface-, ground- and springwater. Combined with extensive drainage of lowland wetlands, which forms artificial redox gradients, accumulations of bright orange (a)biotically-derived Fe-rich flocs are common features of Icelandic wetlands. These loosely consolidated flocs are easily mobilized, and, considering the proximity of Iceland's lowland wetlands to the coast, are likely to contribute to the suspended sediment load transported to coastal waters. To date, however, little is known regarding (Fe) mineral and elemental composition of the flocs. In this study, flocs from wetlands (n = 16) across Iceland were analyzed using X-ray diffraction and spectroscopic techniques (X-ray absorption and 57Fe Mössbauer) combined with chemical extractions and (electron) microscopy to comprehensively characterize floc mineral, elemental, and structural composition. All flocs were rich in Fe (229–414 mg/g), and floc Fe minerals comprised primarily ferrihydrite and nano-crystalline lepidocrocite, with a single floc sample containing nano-crystalline goethite. Floc mineralogy also included Fe in clay minerals and appreciable poorly-crystalline aluminosilicates, most likely allophane and/or imogolite. Microscopy images revealed that floc (bio)organics largely comprised mineral encrusted microbially-derived components (i.e. sheaths, stalks, and EPS) indicative of common FeOB Leptothrix spp. and Gallionella spp. Trace element contents in the flocs were in the low μg/g range, however nearly all trace elements were extracted with hydroxylamine hydrochloride. This finding suggests that the (a)biotic reductive dissolution of ... Article in Journal/Newspaper Iceland ETH Zürich Research Collection |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
topic |
Freshwater flocs Fe(II)-oxidizing bacteria Biominerals Wetlands EXAFS 57Fe Mössbauer |
spellingShingle |
Freshwater flocs Fe(II)-oxidizing bacteria Biominerals Wetlands EXAFS 57Fe Mössbauer Thomas Arrigo, Laurel K. Notini de Andrade, Luiza Shuster, Jeremiah Nydegger, Tabea Vontobel, Sophie Fischer, Stefan Kappler, Andreas Kretzschmar, Ruben Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export |
topic_facet |
Freshwater flocs Fe(II)-oxidizing bacteria Biominerals Wetlands EXAFS 57Fe Mössbauer |
description |
In freshwater wetlands, redox interfaces characterized by circumneutral pH, steep gradients in O2, and a continual supply of Fe(II) form ecological niches favorable to microaerophilic iron(II) oxidizing bacteria (FeOB) and the formation of flocs; associations of (a)biotic mineral phases, microorganisms, and (microbially-derived) organic matter. On the volcanic island of Iceland, wetlands are replenished with Fe-rich surface-, ground- and springwater. Combined with extensive drainage of lowland wetlands, which forms artificial redox gradients, accumulations of bright orange (a)biotically-derived Fe-rich flocs are common features of Icelandic wetlands. These loosely consolidated flocs are easily mobilized, and, considering the proximity of Iceland's lowland wetlands to the coast, are likely to contribute to the suspended sediment load transported to coastal waters. To date, however, little is known regarding (Fe) mineral and elemental composition of the flocs. In this study, flocs from wetlands (n = 16) across Iceland were analyzed using X-ray diffraction and spectroscopic techniques (X-ray absorption and 57Fe Mössbauer) combined with chemical extractions and (electron) microscopy to comprehensively characterize floc mineral, elemental, and structural composition. All flocs were rich in Fe (229–414 mg/g), and floc Fe minerals comprised primarily ferrihydrite and nano-crystalline lepidocrocite, with a single floc sample containing nano-crystalline goethite. Floc mineralogy also included Fe in clay minerals and appreciable poorly-crystalline aluminosilicates, most likely allophane and/or imogolite. Microscopy images revealed that floc (bio)organics largely comprised mineral encrusted microbially-derived components (i.e. sheaths, stalks, and EPS) indicative of common FeOB Leptothrix spp. and Gallionella spp. Trace element contents in the flocs were in the low μg/g range, however nearly all trace elements were extracted with hydroxylamine hydrochloride. This finding suggests that the (a)biotic reductive dissolution of ... |
format |
Article in Journal/Newspaper |
author |
Thomas Arrigo, Laurel K. Notini de Andrade, Luiza Shuster, Jeremiah Nydegger, Tabea Vontobel, Sophie Fischer, Stefan Kappler, Andreas Kretzschmar, Ruben |
author_facet |
Thomas Arrigo, Laurel K. Notini de Andrade, Luiza Shuster, Jeremiah Nydegger, Tabea Vontobel, Sophie Fischer, Stefan Kappler, Andreas Kretzschmar, Ruben |
author_sort |
Thomas Arrigo, Laurel K. |
title |
Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export |
title_short |
Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export |
title_full |
Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export |
title_fullStr |
Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export |
title_full_unstemmed |
Mineral characterization and composition of Fe-rich flocs from wetlands of Iceland: Implications for Fe, C and trace element export |
title_sort |
mineral characterization and composition of fe-rich flocs from wetlands of iceland: implications for fe, c and trace element export |
publisher |
Elsevier |
publishDate |
2022 |
url |
https://hdl.handle.net/20.500.11850/529133 https://doi.org/10.3929/ethz-b-000529133 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Science of The Total Environment, 816 |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.scitotenv.2021.151567 info:eu-repo/semantics/altIdentifier/wos/000766811900012 info:eu-repo/grantAgreement/ETHZ/ETH Seeds/SEED-13 18-2 info:eu-repo/grantAgreement/EC/H2020/788009 http://hdl.handle.net/20.500.11850/529133 doi:10.3929/ethz-b-000529133 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/529133 https://doi.org/10.3929/ethz-b-000529133 https://doi.org/10.1016/j.scitotenv.2021.151567 |
_version_ |
1766037790531780608 |