Effect of anions on dispersion of a kaolinitic soil clay: A combined study of dynamic light scattering and test tube experiments
| Autor: | Nguyen, M.N., Dultz, Stefan, Tran, T.T.T., Bui, A.T.K. |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften
Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft Veterinärmedizin Kaolinitic soil Kaolinitic soils light scattering Negative ions Anion effect Ionic strength Oxalic acid Kaolinite ddc:550 ddc:630 Dispersion (waves) Clay concentration Dispersions Clay fractions Test tube Positively charged Key factors pH Zeta potential anion Dispersion clay soil Anion effects pH effects leaching adsorption Dynamic light scattering Soils Volatile fatty acids Experiments Hydrodynamic Radius |
| Zdroj: | Geoderma 209-210 (2013) |
| Popis: | Dispersion is an important issue for clay leaching in soils. In this study, effects of various anions (Cl-, SO42-, acetate, oxalate and citrate) on dispersion of a kaolinitic soil clay were determined at different pH values and ionic strengths by dynamic light scattering and test tube experiments. Adsorption of anions on clay samples was characterized by the zeta potential (ζ) in a pH range of 2 to 11. At a pH range between 2 and 6, the effects of different anions on decreasing ζ were obvious and followed the order oxalate>citrate>SO42->Cl->acetate, while fluctuated changes in ζ were observed at pH>6. Based on a comparison of hydrodynamic radii (rh) obtained from dynamic light scattering and of transmission of 50% (T50 values) from the test tube experiments, the ability of anions to facilitate the dispersion of the clay fraction followed the sequence of oxalate>citrate>acetate>SO42->Cl-. It implies that adsorption of anions on positively charged edge sites of kaolinite resulting in a decrease in ζ is a key factor for dispersion of the clay fraction. Also, the results suggested that the dynamic light scattering can be used in combination with the test tube experiments in order to evaluate the effect of anions on dispersion at broader ranges of pH, ionic strength and clay concentration. Vietnam National Foundation for Science & Technology Development/105.09-2010.03 |
| Databáze: | OpenAIRE |
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