Pedosphere 5(2): 143--149, 1995
ISSN 1002-0160/CN 32-1315/P
©1995 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effects of sorbed phosphate on kinetics of Cn2+ secondary adsorption of soils |
| ZHOU Dai-Hua, DONG Yuan-Yan, LI Xue-Yuan and XU Feng-Lin |
| Department of Soil Sczence, Huazhong Agricultural University, Wuhan 430070 (China) |
| ABSTRACT |
| The effects of sorbed phosphate on the kinetics of Cu2+ secondary adsorption on three major types of soils in southern and Central China were studied using the batch method and flow (or miscible displacement) techniques. Both of the methods showed that diffusions were the ratedetermining steps in the Cu2+ adsorption by the soils. By the flow method, the course of Cu2+ adsorption kinetics consisted of two steps-sn initial rapid process and a later slow process of Cu2+ adsorption; while by the batch method, the 90% of Cu2+ adsorption reaction was found to finish within first 1 minute. The results obtained using the flow method also indicated that for red soil and yellow-brown soil, Cu2+ adsorptions during the initial reaction periods were restrained when the soils sorbed phosphate, whereas the adsorption reactions were stimulated at the final time. For grey Chao soil, sorbed phosphate retarded the Cu2+ adsorption in the whole reaction period. The results obtained using the batch method and flow techniques all implied that the different effects of sorbed phosphate would be attributed to its effects on Cu2+ ion diffusion in soil solution. |
| Key Words: Cu2+ secondary adsorption, kinetics, soils, sorbed phosphate |
| Citation: Zhou, D. H., Dong, Y. Y., Li, X. Y. and Xu, F. L. 1995. Effects of sorbed phosphate on kinetics of Cn2+ secondary adsorption of soils. Pedosphere. 5(2): 143-149. |
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