Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic
The distribution of dissolved, soluble and colloidal fractions of Al and Ti was assessed by ultrafiltration studies in the upper water column of the eastern tropical North Atlantic. The dissolved fractions of both metals were found to be dominated by the soluble phase smaller than 10 kDa. The colloi...
Published in: | Geochimica et Cosmochimica Acta |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2012
|
Subjects: | |
Online Access: | http://plymsea.ac.uk/id/eprint/5362/ https://doi.org/10.1016/j.gca.2012.07.032 |
id |
ftplymouthml:oai:plymsea.ac.uk:5362 |
---|---|
record_format |
openpolar |
spelling |
ftplymouthml:oai:plymsea.ac.uk:5362 2023-05-15T17:36:17+02:00 Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic Dammshaeuser, A Croot, PL 2012-11 http://plymsea.ac.uk/id/eprint/5362/ https://doi.org/10.1016/j.gca.2012.07.032 unknown Dammshaeuser, A; Croot, PL. 2012 Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic. Geochimica Et Cosmochimica Acta, 96. 304 - 318. https://doi.org/10.1016/j.gca.2012.07.032 <https://doi.org/10.1016/j.gca.2012.07.032> Chemistry Ecology and Environment Marine Sciences Publication - Article PeerReviewed 2012 ftplymouthml https://doi.org/10.1016/j.gca.2012.07.032 2022-09-13T05:48:13Z The distribution of dissolved, soluble and colloidal fractions of Al and Ti was assessed by ultrafiltration studies in the upper water column of the eastern tropical North Atlantic. The dissolved fractions of both metals were found to be dominated by the soluble phase smaller than 10 kDa. The colloidal associations were very low (0.2–3.4%) for Al and not detectable for Ti. These findings are in some contrast to previous estimations for Ti and to the predominant occurrence of both metals as hydrolyzed species in seawater. However, low tendencies to form inorganic colloids can be expected, as in seawater dissolved Al and dissolved Ti are present within their inorganic solubility levels. In addition, association with functional organic groups in the colloidal phase is unlikely for both metals. Vertical distributions of the dissolved fractions showed surface maxima with up to 43 nM of Al and 157 pM of Ti, reflecting their predominant supply from atmospheric sources to the open ocean. In the surface waters, excess dissolved Al over dissolved Ti was present compared to the crustal source, indicating higher solubility and thus elevated inputs of dissolved Al from atmospheric mineral particles. At most stations, subsurface minima of Al and Ti were observed and can be ascribed to scavenging processes and/or biological uptake. The dissolved Al concentrations decreased by 80–90% from the surface maximum to the subsurface minimum. Estimated residence times in the upper 100 m of the water column ranged between 1.6 and 4 years for dissolved Al and between 14 and 17 years for dissolved Ti. The short residence times are in some contrast to the low colloidal associations of Al and Ti and the assumed role of colloids as intermediates in scavenging processes. This suggests that either the removal of both metals occurs predominantly via direct transfer of the hydrolyzed species into the particulate fraction or that the colloidal phase is rapidly turned over in the upper water column. Article in Journal/Newspaper North Atlantic Plymouth Marine Science Electronic Archive (PlyMSEA - Plymouth Marine Laboratory, PML) Geochimica et Cosmochimica Acta 96 304 318 |
institution |
Open Polar |
collection |
Plymouth Marine Science Electronic Archive (PlyMSEA - Plymouth Marine Laboratory, PML) |
op_collection_id |
ftplymouthml |
language |
unknown |
topic |
Chemistry Ecology and Environment Marine Sciences |
spellingShingle |
Chemistry Ecology and Environment Marine Sciences Dammshaeuser, A Croot, PL Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic |
topic_facet |
Chemistry Ecology and Environment Marine Sciences |
description |
The distribution of dissolved, soluble and colloidal fractions of Al and Ti was assessed by ultrafiltration studies in the upper water column of the eastern tropical North Atlantic. The dissolved fractions of both metals were found to be dominated by the soluble phase smaller than 10 kDa. The colloidal associations were very low (0.2–3.4%) for Al and not detectable for Ti. These findings are in some contrast to previous estimations for Ti and to the predominant occurrence of both metals as hydrolyzed species in seawater. However, low tendencies to form inorganic colloids can be expected, as in seawater dissolved Al and dissolved Ti are present within their inorganic solubility levels. In addition, association with functional organic groups in the colloidal phase is unlikely for both metals. Vertical distributions of the dissolved fractions showed surface maxima with up to 43 nM of Al and 157 pM of Ti, reflecting their predominant supply from atmospheric sources to the open ocean. In the surface waters, excess dissolved Al over dissolved Ti was present compared to the crustal source, indicating higher solubility and thus elevated inputs of dissolved Al from atmospheric mineral particles. At most stations, subsurface minima of Al and Ti were observed and can be ascribed to scavenging processes and/or biological uptake. The dissolved Al concentrations decreased by 80–90% from the surface maximum to the subsurface minimum. Estimated residence times in the upper 100 m of the water column ranged between 1.6 and 4 years for dissolved Al and between 14 and 17 years for dissolved Ti. The short residence times are in some contrast to the low colloidal associations of Al and Ti and the assumed role of colloids as intermediates in scavenging processes. This suggests that either the removal of both metals occurs predominantly via direct transfer of the hydrolyzed species into the particulate fraction or that the colloidal phase is rapidly turned over in the upper water column. |
format |
Article in Journal/Newspaper |
author |
Dammshaeuser, A Croot, PL |
author_facet |
Dammshaeuser, A Croot, PL |
author_sort |
Dammshaeuser, A |
title |
Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic |
title_short |
Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic |
title_full |
Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic |
title_fullStr |
Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic |
title_full_unstemmed |
Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic |
title_sort |
low colloidal associations of aluminium and titanium in surface waters of the tropical atlantic |
publishDate |
2012 |
url |
http://plymsea.ac.uk/id/eprint/5362/ https://doi.org/10.1016/j.gca.2012.07.032 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Dammshaeuser, A; Croot, PL. 2012 Low colloidal associations of aluminium and titanium in surface waters of the tropical Atlantic. Geochimica Et Cosmochimica Acta, 96. 304 - 318. https://doi.org/10.1016/j.gca.2012.07.032 <https://doi.org/10.1016/j.gca.2012.07.032> |
op_doi |
https://doi.org/10.1016/j.gca.2012.07.032 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
96 |
container_start_page |
304 |
op_container_end_page |
318 |
_version_ |
1766135722522181632 |