In
soils, dispersion is a crucial steppreceding the loss of clay-sizedparticles by
surface run-off and leaching, which in turn results in soil degradation.
Despite
the fact that silicic acid is common in soil solutions, its effect on
aggre-gation stability offine sized particles in soils has not been detailed.
Here
we examined the effect of silicic acid on dispersion of a kaolinitic soil clay
fraction rich in Fe-oxides (8.5%) at different pH values by combining dynamic
light scattering for particle sizing and test tube experiments for examination
of particles in suspension.
Adsorp-tion
of silicic acid on the clay fraction was characterized by batch adsorption
experiments and effects on surface chargeby zeta potential (ζ)measurements over
a pH range from2 to 11.
We
found that silicic acidadsorbedonto clay and co-existing Fe oxides, madeζmore
negative, and thereby counteracted aggregation of the clay fraction. Silicic
acid showed its most effectivity for maintaining dispersion at a pH range of 4
to 6.
Beyond
this pH range, dispersion was either strongly favored or prevented, and the
effect of silicic acid on dispersion was obscured.
Given
the ubiquitous presence of silicic acid in soils, ourfindings regarding its
impact on aggregation stability have important implication for conservation of
acidic soils.
| Title: | Silicic acid as a dispersibility enhancer in a Fe-oxide-rich kaolinitic soil clay |
| Authors: | Nguyen, Minh N. Picardal, Flynn Dultz, Stefan Nguyen Anh V. Nguyen Khai M. |
| Keywords: | Silicic acid Kaolinitic soil Dispersion Light scattering Zeta potential |
| Issue Date: | 2017 |
| Publisher: | ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS |
| Citation: | ISIKNOWLEDGE |
| Abstract: | Insoils, dispersion is a crucial steppreceding the loss of clay-sizedparticles by surface run-off and leaching,which in turn results in soil degradation. Despite the fact that silicic acid is common in soil solutions, its effect on aggre-gation stability offine sized particles in soils has not been detailed. Here we examined the effect of silicic acid on dispersion of a kaolinitic soil clay fraction rich in Fe-oxides (8.5%) at different pH values by combining dynamic light scattering for particle sizing and test tube experiments for examination of particles in suspension. Adsorp-tion of silicic acid on the clay fraction was characterized by batch adsorption experiments and effects on surface chargeby zeta potential (ζ)measurements over a pH range from2 to 11.We found that silicic acidadsorbedonto clay and co-existing Fe oxides, madeζmore negative, and thereby counteracted aggregation of the clay fraction. Silicic acid showed its most effectivity for maintaining dispersion at a pH range of 4 to 6. Beyond this pH range, dispersion was either strongly favored or prevented, and the effect of silicic acid on dispersion was obscured. Given the ubiquitous presence of silicic acid in soils, ourfindings regarding its impact on aggregation stability have important implication for conservation of acidic soils. |
| Description: | TNS07005 ; GEODERMA Volume: 286 Pages: 8-14 Published: JAN 15 2017 |
| URI: | http://repository.vnu.edu.vn/handle/VNU_123/28782 http://www.sciencedirect.com/science/article/pii/S0016706116306760 |
| ISSN: | 0016-7061 1872-6259 |
| Appears in Collections: | Bài báo của ĐHQGHN trong Web of Science |
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