Pedosphere 4(2): 173--180, 1994
ISSN 1002-0160/CN 32-1315/P
©1994 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Proton Dissociation from Surfaces of Variable Charge Soil andMnierals |
| LU YA-HAI1, HUANG CHANG-YONG1, YUAN KE-NENG1, ZHU ZU-XIANG1 |
| Departrment of Soil, Plant Nutrition, China National Rice Research Institute, Hangzhou 310006 |
| ABSTRACT |
| Experiments on proton dissociation from the surfaces of goethite, amorphous Al oxide, kaolinite and latosol were carried out, showing amphoteric behavior with reactions of proton dissociation-association on the surfaces and buffering capacity in such a sequence as amorphous Al oxide>latosol>kaolinite>goethite. Dissociation constants of surface proton, pKsa, are significantly correlated with surface charge density, which has been proved with an electrochemical model. The intrinsic constants of proton dissociation, Ksa(int), gained by extrapolation to zero charge conditions of plots of pKsa against ao, could be used to estimate the acidity strength of variable charge surfaces. The value of pKse(int) is 8.08 for goethite, 1.2 for morphous Al oxide, 6.62 for kaolinite and 5.32 for latosol. |
| Key Words: |
| Citation: Lu, Y. H., Huang, C. Y., Yuan, K. N. and Zhu, Z. X. 1994. Proton Dissociation from Surfaces of Variable Charge Soil andMnierals. Pedosphere. 4(2): 173-180. |
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