Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials

Timothy Payne, James A. Davis, Michael Ochs, Markus Olin, Cherry J. Tweed, Scott Altmann, Mehdi M. Askarieh

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleScientificpeer-review

6 Citations (Scopus)

Abstract

This chapter summaries a major international modelling exercise, co-ordinated by the OECD Nuclear Energy Agency, in which independent scientific teams applied thermodynamic sorption models (TSMs) to a number of experimental adsorption data sets. A wide variety of models was employed to simulate and predict the data. In all the test cases, reasonable, broadly similar TSM approaches were adopted, but based on wide diversity of assumptions and methods of parameter estimation. The models were able to realistically, and with some predictive power, simulate the experimental data for a range of substrates, radionuclides and chemical conditions.However, sorption modelling has not reached a stage approaching standardisation. Basic features such as the stoichiometry and structure of surface complexes and mathematical formulations for such model components as the EDL are subject to debate. In addition, key model input parameters such as site populations are not well defined (particularly for natural substrates).As a result, the numerical values of optimised model parameters are highly model- dependent, which means that, in the present study, it has not been meaningful to compare individual model parameters (such as log K values for surface complexes). If a consensus is reached on model components, and uniform modelling approaches are adopted, it will be appropriate to do such a comparison.Until that time, modellers need to recognise that model parameters can typically not be used directly in other models, but that they need to be scaled or re-fitted.Although the modelling strategies differed among the teams, all were guided by a single principle, representation of sorption in terms of mass action and mass balance laws. The generally satisfactory results of this intercomparison suggest that these types of models have inbuilt chemical plausibility and predictive capabililty.
Original languageEnglish
Title of host publicationSurface Complexation Modelling
EditorsJohannes Lutzenkirchen
Place of PublicationAmsterdam, The Netherlands
PublisherAcademic Press
Chapter22
Pages605-633
ISBN (Electronic)978-0-080-467-788
ISBN (Print)978-0-12-372572-1
DOIs
Publication statusPublished - 2006
MoE publication typeA3 Part of a book or another research book

Fingerprint

complexation
radionuclide
sorption
evaluation
material
modeling
thermodynamics
substrate
stoichiometry
OECD
standardization
mass balance
adsorption

Cite this

Payne, T., Davis, J. A., Ochs, M., Olin, M., Tweed, C. J., Altmann, S., & Askarieh, M. M. (2006). Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials. In J. Lutzenkirchen (Ed.), Surface Complexation Modelling (pp. 605-633). Amsterdam, The Netherlands: Academic Press. https://doi.org/10.1016/S1573-4285(06)80066-9
Payne, Timothy ; Davis, James A. ; Ochs, Michael ; Olin, Markus ; Tweed, Cherry J. ; Altmann, Scott ; Askarieh, Mehdi M. / Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials. Surface Complexation Modelling. editor / Johannes Lutzenkirchen. Amsterdam, The Netherlands : Academic Press, 2006. pp. 605-633
@inbook{92e729a81b1f47b5906a8df40982be44,
title = "Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials",
abstract = "This chapter summaries a major international modelling exercise, co-ordinated by the OECD Nuclear Energy Agency, in which independent scientific teams applied thermodynamic sorption models (TSMs) to a number of experimental adsorption data sets. A wide variety of models was employed to simulate and predict the data. In all the test cases, reasonable, broadly similar TSM approaches were adopted, but based on wide diversity of assumptions and methods of parameter estimation. The models were able to realistically, and with some predictive power, simulate the experimental data for a range of substrates, radionuclides and chemical conditions.However, sorption modelling has not reached a stage approaching standardisation. Basic features such as the stoichiometry and structure of surface complexes and mathematical formulations for such model components as the EDL are subject to debate. In addition, key model input parameters such as site populations are not well defined (particularly for natural substrates).As a result, the numerical values of optimised model parameters are highly model- dependent, which means that, in the present study, it has not been meaningful to compare individual model parameters (such as log K values for surface complexes). If a consensus is reached on model components, and uniform modelling approaches are adopted, it will be appropriate to do such a comparison.Until that time, modellers need to recognise that model parameters can typically not be used directly in other models, but that they need to be scaled or re-fitted.Although the modelling strategies differed among the teams, all were guided by a single principle, representation of sorption in terms of mass action and mass balance laws. The generally satisfactory results of this intercomparison suggest that these types of models have inbuilt chemical plausibility and predictive capabililty.",
author = "Timothy Payne and Davis, {James A.} and Michael Ochs and Markus Olin and Tweed, {Cherry J.} and Scott Altmann and Askarieh, {Mehdi M.}",
year = "2006",
doi = "10.1016/S1573-4285(06)80066-9",
language = "English",
isbn = "978-0-12-372572-1",
pages = "605--633",
editor = "Johannes Lutzenkirchen",
booktitle = "Surface Complexation Modelling",
publisher = "Academic Press",
address = "United States",

}

Payne, T, Davis, JA, Ochs, M, Olin, M, Tweed, CJ, Altmann, S & Askarieh, MM 2006, Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials. in J Lutzenkirchen (ed.), Surface Complexation Modelling. Academic Press, Amsterdam, The Netherlands, pp. 605-633. https://doi.org/10.1016/S1573-4285(06)80066-9

Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials. / Payne, Timothy ; Davis, James A. ; Ochs, Michael ; Olin, Markus; Tweed, Cherry J. ; Altmann, Scott; Askarieh, Mehdi M.

Surface Complexation Modelling. ed. / Johannes Lutzenkirchen. Amsterdam, The Netherlands : Academic Press, 2006. p. 605-633.

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleScientificpeer-review

TY - CHAP

T1 - Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials

AU - Payne, Timothy

AU - Davis, James A.

AU - Ochs, Michael

AU - Olin, Markus

AU - Tweed, Cherry J.

AU - Altmann, Scott

AU - Askarieh, Mehdi M.

PY - 2006

Y1 - 2006

N2 - This chapter summaries a major international modelling exercise, co-ordinated by the OECD Nuclear Energy Agency, in which independent scientific teams applied thermodynamic sorption models (TSMs) to a number of experimental adsorption data sets. A wide variety of models was employed to simulate and predict the data. In all the test cases, reasonable, broadly similar TSM approaches were adopted, but based on wide diversity of assumptions and methods of parameter estimation. The models were able to realistically, and with some predictive power, simulate the experimental data for a range of substrates, radionuclides and chemical conditions.However, sorption modelling has not reached a stage approaching standardisation. Basic features such as the stoichiometry and structure of surface complexes and mathematical formulations for such model components as the EDL are subject to debate. In addition, key model input parameters such as site populations are not well defined (particularly for natural substrates).As a result, the numerical values of optimised model parameters are highly model- dependent, which means that, in the present study, it has not been meaningful to compare individual model parameters (such as log K values for surface complexes). If a consensus is reached on model components, and uniform modelling approaches are adopted, it will be appropriate to do such a comparison.Until that time, modellers need to recognise that model parameters can typically not be used directly in other models, but that they need to be scaled or re-fitted.Although the modelling strategies differed among the teams, all were guided by a single principle, representation of sorption in terms of mass action and mass balance laws. The generally satisfactory results of this intercomparison suggest that these types of models have inbuilt chemical plausibility and predictive capabililty.

AB - This chapter summaries a major international modelling exercise, co-ordinated by the OECD Nuclear Energy Agency, in which independent scientific teams applied thermodynamic sorption models (TSMs) to a number of experimental adsorption data sets. A wide variety of models was employed to simulate and predict the data. In all the test cases, reasonable, broadly similar TSM approaches were adopted, but based on wide diversity of assumptions and methods of parameter estimation. The models were able to realistically, and with some predictive power, simulate the experimental data for a range of substrates, radionuclides and chemical conditions.However, sorption modelling has not reached a stage approaching standardisation. Basic features such as the stoichiometry and structure of surface complexes and mathematical formulations for such model components as the EDL are subject to debate. In addition, key model input parameters such as site populations are not well defined (particularly for natural substrates).As a result, the numerical values of optimised model parameters are highly model- dependent, which means that, in the present study, it has not been meaningful to compare individual model parameters (such as log K values for surface complexes). If a consensus is reached on model components, and uniform modelling approaches are adopted, it will be appropriate to do such a comparison.Until that time, modellers need to recognise that model parameters can typically not be used directly in other models, but that they need to be scaled or re-fitted.Although the modelling strategies differed among the teams, all were guided by a single principle, representation of sorption in terms of mass action and mass balance laws. The generally satisfactory results of this intercomparison suggest that these types of models have inbuilt chemical plausibility and predictive capabililty.

U2 - 10.1016/S1573-4285(06)80066-9

DO - 10.1016/S1573-4285(06)80066-9

M3 - Chapter or book article

SN - 978-0-12-372572-1

SP - 605

EP - 633

BT - Surface Complexation Modelling

A2 - Lutzenkirchen, Johannes

PB - Academic Press

CY - Amsterdam, The Netherlands

ER -

Payne T, Davis JA, Ochs M, Olin M, Tweed CJ, Altmann S et al. Comparative Evaluation of Surface Complexation Models for Radionuclide Sorption by Diverse Geologic Materials. In Lutzenkirchen J, editor, Surface Complexation Modelling. Amsterdam, The Netherlands: Academic Press. 2006. p. 605-633 https://doi.org/10.1016/S1573-4285(06)80066-9