Contribution of ferric iron to light absorption by chromophoric dissolved organic matter
This study experimentally determined the contribution of ferric iron (Fe(III)) associated with humic substances (HS) to light absorption by chromophoric dissolved organic matter (CDOM). The associations between Fe(III) and HS (HS‐Fe) were generated by mixing HS standards with Fe(III) in acidic condi...
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crwiley:10.4319/lo.2013.58.2.0653 2024-09-09T19:09:15+00:00 Contribution of ferric iron to light absorption by chromophoric dissolved organic matter Xiao, Yi-Hua Sara-Aho, Timo Hartikainen, Helinä Vähätalo, Anssi V. 2013 http://dx.doi.org/10.4319/lo.2013.58.2.0653 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.2013.58.2.0653 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2013.58.2.0653 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Limnology and Oceanography volume 58, issue 2, page 653-662 ISSN 0024-3590 1939-5590 journal-article 2013 crwiley https://doi.org/10.4319/lo.2013.58.2.0653 2024-07-30T04:23:35Z This study experimentally determined the contribution of ferric iron (Fe(III)) associated with humic substances (HS) to light absorption by chromophoric dissolved organic matter (CDOM). The associations between Fe(III) and HS (HS‐Fe) were generated by mixing HS standards with Fe(III) in acidic conditions and adjusting pH to 8. HS‐associated Fe was separated from total Fe by filtering (0.7 µm and 0.2 µm filters) and by removing the free Fe ions by cation exchange chromatography. The maximum Fe‐binding capacities (at pH 8) of Suwannee River humic acid, Suwannee River fulvic acid, and Pony Lake (Antarctica) fulvic acid were 13.0, 13.5, and 7.64 µmol Fe [mg C] −1 , respectively, indicating that wetland‐derived HS had a higher Fe‐binding capacity than plankton‐derived HS. HS‐associated Fe increased the absorption coefficient of CDOM by up to several fold in the visible range of the spectrum and reduced the spectral slope coefficient of CDOM. The Fe‐induced increase in light absorption was spectrally similar among different HS examined. The Fe‐specific absorption coefficient spectrum for HS‐associated Fe ( a λ, Fe *) was calculated from the Fe‐induced increase in light absorption by normalizing it with the concentration of Fe in the HS pool. The a λ, Fe * was adopted in estimation of the contribution of HS‐associated Fe to light absorption by CDOM in 13 circum‐neutral natural waters collected from a spring, 10 major rivers, a lake, and a coastal area. HS‐associated Fe was calculated to be responsible for from 0.6% (Mississippi River) to 56.4% (Löytynlähde spring) of light absorption by CDOM at a wavelength of 410 nm. This study shows that HS‐associated Fe can be an important component in light absorption by CDOM and also influence the spectral slope coefficient of CDOM. Article in Journal/Newspaper Antarc* Antarctica Wiley Online Library Pony Lake ENVELOPE(166.150,166.150,-77.550,-77.550) Suwannee River ENVELOPE(-100.046,-100.046,56.125,56.125) Limnology and Oceanography 58 2 653 662 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
This study experimentally determined the contribution of ferric iron (Fe(III)) associated with humic substances (HS) to light absorption by chromophoric dissolved organic matter (CDOM). The associations between Fe(III) and HS (HS‐Fe) were generated by mixing HS standards with Fe(III) in acidic conditions and adjusting pH to 8. HS‐associated Fe was separated from total Fe by filtering (0.7 µm and 0.2 µm filters) and by removing the free Fe ions by cation exchange chromatography. The maximum Fe‐binding capacities (at pH 8) of Suwannee River humic acid, Suwannee River fulvic acid, and Pony Lake (Antarctica) fulvic acid were 13.0, 13.5, and 7.64 µmol Fe [mg C] −1 , respectively, indicating that wetland‐derived HS had a higher Fe‐binding capacity than plankton‐derived HS. HS‐associated Fe increased the absorption coefficient of CDOM by up to several fold in the visible range of the spectrum and reduced the spectral slope coefficient of CDOM. The Fe‐induced increase in light absorption was spectrally similar among different HS examined. The Fe‐specific absorption coefficient spectrum for HS‐associated Fe ( a λ, Fe *) was calculated from the Fe‐induced increase in light absorption by normalizing it with the concentration of Fe in the HS pool. The a λ, Fe * was adopted in estimation of the contribution of HS‐associated Fe to light absorption by CDOM in 13 circum‐neutral natural waters collected from a spring, 10 major rivers, a lake, and a coastal area. HS‐associated Fe was calculated to be responsible for from 0.6% (Mississippi River) to 56.4% (Löytynlähde spring) of light absorption by CDOM at a wavelength of 410 nm. This study shows that HS‐associated Fe can be an important component in light absorption by CDOM and also influence the spectral slope coefficient of CDOM. |
format |
Article in Journal/Newspaper |
author |
Xiao, Yi-Hua Sara-Aho, Timo Hartikainen, Helinä Vähätalo, Anssi V. |
spellingShingle |
Xiao, Yi-Hua Sara-Aho, Timo Hartikainen, Helinä Vähätalo, Anssi V. Contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
author_facet |
Xiao, Yi-Hua Sara-Aho, Timo Hartikainen, Helinä Vähätalo, Anssi V. |
author_sort |
Xiao, Yi-Hua |
title |
Contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
title_short |
Contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
title_full |
Contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
title_fullStr |
Contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
title_full_unstemmed |
Contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
title_sort |
contribution of ferric iron to light absorption by chromophoric dissolved organic matter |
publisher |
Wiley |
publishDate |
2013 |
url |
http://dx.doi.org/10.4319/lo.2013.58.2.0653 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.2013.58.2.0653 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2013.58.2.0653 |
long_lat |
ENVELOPE(166.150,166.150,-77.550,-77.550) ENVELOPE(-100.046,-100.046,56.125,56.125) |
geographic |
Pony Lake Suwannee River |
geographic_facet |
Pony Lake Suwannee River |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Limnology and Oceanography volume 58, issue 2, page 653-662 ISSN 0024-3590 1939-5590 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.4319/lo.2013.58.2.0653 |
container_title |
Limnology and Oceanography |
container_volume |
58 |
container_issue |
2 |
container_start_page |
653 |
op_container_end_page |
662 |
_version_ |
1809823523596664832 |