Pedosphere 2(3): 273--282, 1992
ISSN 1002-0160/CN 32-1315/P
©1992 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Adsorption of Phosphate on Variable Charge Soils |
| HU GUO-SONG, ZHU ZU-XIANG, YUAN KE-NENG |
| Department of Sell and Agricultural Chemistry, Zhejiang Agricultural University, Hangzhou 310029 |
| ABSTRACT |
| The study about the adsorption of phosphate on four variable charge soils and some minerals revealed that two stage adsorption appeared in the adsorption isotherms of phosphate on 4 soils and there was a maximum adsorption on Al-oxide-typed surfaces between pH 3.5 to pH 5.5 as suspension pH changed from 2 to 9, but the adsorption amount of phosphate decreased continually as pH rose on Fe-oxide typed surfaces. The adsorption amount of phosphate and the maximum phosphate adsorption pH decreased in the order of yellow-red soil > lateritic red soil > red soil > paddy soil, which was coincided with the content order of amorphous Al oxide. The removement of organic matter and Fe oxide made the maximum phosphate adsorption pH rise from 4.0 to 5.0 and 4.5, respectively. The desorption curves with pH of four soils showed that phosphate desorbed least at pH 5. Generally the desorption was contrary to the adsorption with pH changing. |
| Key Words: |
| Citation: Hu, G. S., Zhu, Z. X. and Yuan, K. N. 1992. Adsorption of Phosphate on Variable Charge Soils. Pedosphere. 2(3): 273-282. |
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