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Updated: Jul 17, 2026
10:22
In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions
Published on: June 16, 2014
Modeling the interactions between humics, ions, and mineral surfaces
Willem H van Riemsdijk1, Luuk K Koopal, David G Kinniburgh
1Soil Quality Department, Wageningen University, P.O. Box 8005, 6700 EC, Wageningen, The Netherlands. willem.vanriemsdijk@wur.nl
Environmental Science & Technology
|January 30, 2007
Summary
Two models, Model VI and the NICA-Donnan model, describe metal ion binding by humic materials. The NICA-Donnan model
Area of Science:
- Environmental Chemistry
- Soil Science
- Geochemistry
Background:
- Metal ion binding by humic materials is complex, involving heterogeneity, stoichiometry, and electrostatics.
- Model VI and the NICA-Donnan model are established frameworks for describing these interactions.
- Understanding these processes is crucial for environmental and geochemical applications.
Purpose of the Study:
- To discuss the parameters and determination of the NICA-Donnan model.
- To interpret the role of ion-specific non-ideality parameters in competitive ion binding.
- To compare Model VI and the NICA-Donnan model and highlight potential differences.
Main Methods:
- Discussion of the NICA-Donnan model parameters and their determination.
- Analysis of ion-specific non-ideality parameters (ni) and their relation to stoichiometry.
- Comparison of Model VI and NICA-Donnan models, including their application to humic-oxide complexes.
Main Results:
- The NICA-Donnan model's non-ideality parameters (ni) are key to understanding competitive ion binding stoichiometry.
- The ratio nM/nH influences exchange ratios and pH-dependent metal ion binding.
- Combined models (NICA-Donnan and CD-MUSIC) are used for humic-oxide complex interactions.
Conclusions:
- Both Model VI and NICA-Donnan offer pragmatic approaches to complex metal ion binding.
- Further testing may reveal more distinct differences between Model VI and NICA-Donnan.
- The NICA-Donnan model, when combined with other models, can describe ion binding in complex humic-oxide systems.
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