Title: Partition coefficient of 234Th, 233Pa, 210Pb, 210Po, and 7Be

Type Dataset Santschi, Peter, Quigg, Antonietta, Schwehr, Kathleen, Xu, Chen (2019-04-11): Partition coefficient of 234Th, 233Pa, 210Pb, 210Po, and 7Be. Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu. Dataset. https://darchive.mblwhoilibrary.org/handle/1912/24004

Authors: Santschi, Peter ; Quigg, Antonietta ; Schwehr, Kathleen ; Xu, Chen ;

Links

• Item record in Woods Hole Open Access Server
• Digital object URL

Summary

Laboratory studies were conducted to examine the sorption of selected radionuclides (234Th, 233Pa, 210Po, 210Pb, and 7Be) onto inorganic (pure silica and acid-cleaned diatom frustules) and organic (diatom cells with or without silica frustules) particles in natural seawater and the role of templating biomolecules and exopolymeric substances (EPS) extracted from the same species of diatom, Phaeodactylum tricornutum, in the sorption process. The range of partition coefficients (Kd, reported as logKd) of radionuclides between water and the different particle types was 4.78–6.69 for 234Th, 5.23–6.71 for 233Pa, 4.44–5.86 for 210Pb, 4.47–4.92 for 210Po, and 4.93–7.23 for 7Be, similar to values reported for lab and field determinations. The sorption of all radionuclides was significantly enhanced in the presence of organic matter associated with particles, resulting in Kd one to two orders of magnitude higher than for inorganic particles only, with highest values for 7Be (logKd of 7.2). Results further indicate that EPS and frustule-embedded biomolecules in diatom cells are responsible for the sorption enhancement rather than the silica shell itself. By separating radiolabeled EPS via isoelectric focusing, we found that isoelectric points are radionuclide specific, suggesting that each radionuclide binds to specific biopolymeric functional groups, with the most efficient binding sites likely occurring in acid polysaccharides, iron hydroxides, and proteins. Further progress in evaluating the effects of diatom frustule–related biopolymers on binding, scavenging, and fractionation of radionuclides would require the application of molecular-level characterization techniques. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/764664

More information

• URI: https://hdl.handle.net/1912/24004
• DOI: 10.1575/1912/bco-dmo.764664.1
• Language: en_US

Dates

• accessioned: April 11, 2019
• available: April 11, 2019
• created: April 10, 2019
• Publication date: April 11, 2019

Notes

Rights

• Creative Commons Attribution 4.0
• https://creativecommons.org/licenses/by/4.0/

Funding Information

Format

electronic resource

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