A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Diffusion of lignosulfonate colloids in compacted bentonite
AbstractColloids, 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/cm3 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 cm2/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 ≥0.01 M NaClO4 provides enough ions to shield the charged sites on the colloids, and the colloids can coil into smaller units.
Diffusion of lignosulfonate colloids in compacted bentonite
AbstractColloids, 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/cm3 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 cm2/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 ≥0.01 M NaClO4 provides enough ions to shield the charged sites on the colloids, and the colloids can coil into smaller units.
Diffusion of lignosulfonate colloids in compacted bentonite
Wold, S. (author) / Eriksen, T.E. (author)
Applied Clay Science ; 23 ; 43-50
2003-01-01
8 pages
Article (Journal)
Electronic Resource
English
Diffusion of lignosulfonate colloids in compacted bentonite
| Online Contents | 2003
Diffusion of lignosulfonate colloids in compacted bentonite
| British Library Conference Proceedings | 2003
Diffusion of uranium in compacted sodium bentonite
| Elsevier | 1989
Sorption effects on cation diffusion in compacted bentonite
| British Library Online Contents | 1999
Sorption effects on cation diffusion in compacted bentonite
| Online Contents | 2000