Change search
ReferencesLink to record
Permanent link

Direct link
Diffusion of lignosulfonate colloids in compacted bentonite
KTH, Superseded Departments, Chemistry.
2003 (English)In: Applied Clay Science, ISSN 0169-1317, E-ISSN 1872-9053, Vol. 23, no 04-jan, 43-50 p.Article in journal (Refereed) Published
Abstract [en]

Colloids, as humic acid, are known to be strong complexing agent for radionuclides. If such colloids are introduced into the bentonite barrier in a repository for spent fuel, the diffusivities for radionuclides can change. The colloid complexed radionuclides diffusivities will be governed by the colloidal diffusivities, and the transport of strongly bentonite sorbed radionuclides might be facilitated into the biosphere. The diffusive properties of Lignosulfonate (LS) colloids dissolved in 0.01 and 0.1 M NaClO4 in bentonite of dry densities 0.6, 0.8, 1.0, 1.2, 1.5, and 1.8 g/cm(3) are studied. LS is used as a model substance for humic acid. Independent of ionic strength and of dry density apparent diffusivities in the order of 10(-8) cm(2)/s were obtained. The ratios of effective diffusivity/apparent diffusivity are in accordance with the porosities of the bentonite. The diffusing colloids were not found to be hindered by ionic exclusion or by filtering effects. The results indicate that the LS diffuse through the bentonite as small uncharged colloids. It seems that ionic strength greater than or equal to 0.01 M NaClO4 provides enough ions to shield the charged sites on the colloids, and the colloids can coil into smaller units.

Place, publisher, year, edition, pages
2003. Vol. 23, no 04-jan, 43-50 p.
Keyword [en]
lignosulfonate colloids, diffusivity, transport capacity, coiling, shielding of charges, granitic groundwater systems, radionuclide migration, humic-acid, stability
URN: urn:nbn:se:kth:diva-22902ISI: 000186093500006OAI: diva2:341600
QC 20100525Available from: 2010-08-10 Created: 2010-08-10Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Wold, Susanna
By organisation
In the same journal
Applied Clay Science

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 33 hits
ReferencesLink to record
Permanent link

Direct link