A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration
Ikaite (CaCO3·6H2O) has only recently been discovered in sea ice, in a study that also provided first direct evidence of CaCO3 precipitation in sea ice. However, little is as yet known about the impact of physico-chemical processes on ikaite precipitation in sea ice. Our study focused on how the cha...
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ftawi:oai:epic.awi.de:35297 2024-09-15T18:34:35+00:00 A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration Hu, Yu-Bin Wolf-Gladrow, Dieter A. Dieckmann, Gerhard S. Völker, Christoph Nehrke, Gernot 2014-05-20 application/pdf https://epic.awi.de/id/eprint/35297/ https://epic.awi.de/id/eprint/35297/1/MarChem-2014.pdf http://www.sciencedirect.com/science/article/pii/S0304420314000279 https://hdl.handle.net/10013/epic.43309 https://hdl.handle.net/10013/epic.43309.d001 unknown Elsevier https://epic.awi.de/id/eprint/35297/1/MarChem-2014.pdf https://hdl.handle.net/10013/epic.43309.d001 Hu, Y. B. , Wolf-Gladrow, D. A. orcid:0000-0001-9531-8668 , Dieckmann, G. S. , Völker, C. orcid:0000-0003-3032-114X and Nehrke, G. orcid:0000-0002-2851-3049 (2014) A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration , Marine Chemistry, 162 , pp. 10-18 . doi:10.1016/j.marchem.2014.02.003 <https://doi.org/10.1016/j.marchem.2014.02.003> , hdl:10013/epic.43309 EPIC3Marine Chemistry, Elsevier, 162, pp. 10-18, ISSN: 0304-4203 Article isiRev 2014 ftawi https://doi.org/10.1016/j.marchem.2014.02.003 2024-06-24T04:08:32Z Ikaite (CaCO3·6H2O) has only recently been discovered in sea ice, in a study that also provided first direct evidence of CaCO3 precipitation in sea ice. However, little is as yet known about the impact of physico-chemical processes on ikaite precipitation in sea ice. Our study focused on how the changes in pH, salinity, temperature and phosphate (PO4) concentration affect the precipitation of ikaite. Experiments were set up at pH from 8.5 to 10.0, salinities from 0 to 105 (in both artificial seawater (ASW) and NaCl medium), temperatures from 0 to −4 °C andPO4 concentrations from0 to 50 μmol kg−1. The results show that in ASW, calcium carbonate was precipitated as ikaite under all conditions. In the NaCl medium, the precipitates were ikaite in the presence of PO4 and vaterite in the absence of PO4. The onset time (τ) at which ikaite precipitation started, decreased nonlinearly with increasing pH. In ASW, τ increased with salinity. In the NaCl medium, τ first increased with salinity up to salinity 70 and subsequently decreased with a further increase in salinity; it was longer in ASW than in the NaCl medium under the same salinity. τ did not vary with temperature or PO4 concentration. These results indicate that ikaite is very probably the only phase of calcium carbonate formed in sea ice. PO4 is not, as previously postulated, crucial for ikaite formation in sea ice. The change in pH and salinity is the controlling factor for ikaite precipitation in sea ice. Within the ranges investigated in this study, temperature and PO4 concentration do not have a significant impact on ikaite precipitation. Article in Journal/Newspaper Sea ice Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Marine Chemistry 162 10 18 |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Ikaite (CaCO3·6H2O) has only recently been discovered in sea ice, in a study that also provided first direct evidence of CaCO3 precipitation in sea ice. However, little is as yet known about the impact of physico-chemical processes on ikaite precipitation in sea ice. Our study focused on how the changes in pH, salinity, temperature and phosphate (PO4) concentration affect the precipitation of ikaite. Experiments were set up at pH from 8.5 to 10.0, salinities from 0 to 105 (in both artificial seawater (ASW) and NaCl medium), temperatures from 0 to −4 °C andPO4 concentrations from0 to 50 μmol kg−1. The results show that in ASW, calcium carbonate was precipitated as ikaite under all conditions. In the NaCl medium, the precipitates were ikaite in the presence of PO4 and vaterite in the absence of PO4. The onset time (τ) at which ikaite precipitation started, decreased nonlinearly with increasing pH. In ASW, τ increased with salinity. In the NaCl medium, τ first increased with salinity up to salinity 70 and subsequently decreased with a further increase in salinity; it was longer in ASW than in the NaCl medium under the same salinity. τ did not vary with temperature or PO4 concentration. These results indicate that ikaite is very probably the only phase of calcium carbonate formed in sea ice. PO4 is not, as previously postulated, crucial for ikaite formation in sea ice. The change in pH and salinity is the controlling factor for ikaite precipitation in sea ice. Within the ranges investigated in this study, temperature and PO4 concentration do not have a significant impact on ikaite precipitation. |
format |
Article in Journal/Newspaper |
author |
Hu, Yu-Bin Wolf-Gladrow, Dieter A. Dieckmann, Gerhard S. Völker, Christoph Nehrke, Gernot |
spellingShingle |
Hu, Yu-Bin Wolf-Gladrow, Dieter A. Dieckmann, Gerhard S. Völker, Christoph Nehrke, Gernot A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration |
author_facet |
Hu, Yu-Bin Wolf-Gladrow, Dieter A. Dieckmann, Gerhard S. Völker, Christoph Nehrke, Gernot |
author_sort |
Hu, Yu-Bin |
title |
A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration |
title_short |
A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration |
title_full |
A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration |
title_fullStr |
A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration |
title_full_unstemmed |
A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration |
title_sort |
laboratory study of ikaite (caco3·6h2o) precipitation as a function of ph, salinity, temperature and phosphate concentration |
publisher |
Elsevier |
publishDate |
2014 |
url |
https://epic.awi.de/id/eprint/35297/ https://epic.awi.de/id/eprint/35297/1/MarChem-2014.pdf http://www.sciencedirect.com/science/article/pii/S0304420314000279 https://hdl.handle.net/10013/epic.43309 https://hdl.handle.net/10013/epic.43309.d001 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
EPIC3Marine Chemistry, Elsevier, 162, pp. 10-18, ISSN: 0304-4203 |
op_relation |
https://epic.awi.de/id/eprint/35297/1/MarChem-2014.pdf https://hdl.handle.net/10013/epic.43309.d001 Hu, Y. B. , Wolf-Gladrow, D. A. orcid:0000-0001-9531-8668 , Dieckmann, G. S. , Völker, C. orcid:0000-0003-3032-114X and Nehrke, G. orcid:0000-0002-2851-3049 (2014) A laboratory study of ikaite (CaCO3·6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration , Marine Chemistry, 162 , pp. 10-18 . doi:10.1016/j.marchem.2014.02.003 <https://doi.org/10.1016/j.marchem.2014.02.003> , hdl:10013/epic.43309 |
op_doi |
https://doi.org/10.1016/j.marchem.2014.02.003 |
container_title |
Marine Chemistry |
container_volume |
162 |
container_start_page |
10 |
op_container_end_page |
18 |
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1810476472586993664 |