Characterization of zinc adsorption sites in two mineral soils |
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| Authors: | Koji Wada Aly Abd-Elfattah |
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| Institution: | Faculty of Agriculture , Kyushu University , Fukuoka , Japan |
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| Abstract: | The adsorption of Zn, as compared with Mg, on two mineral soils, which differed in their major cation-exchange materials and with and without Ca-saturation, was measured in the presence of free CaCl2. The adsorption of Zn as well as Mg occurred on cation-exchange sites. The Zn adsorption data conformed to a two-term Langmuir equation. The presence of two kinds of adsorption sites and their numbers and bonding energies were deduced. However, the Langmuir approach was not adopted on the basis of comparison between the total number of the adsorption sites for Zn deduced and the CEC of the soils. As an alternative approach, the selectivity coefficient  was calculated for each adsorption equilibrium and plotted against the amount of Zn adsorbed. This ![/></span>Zn]<sub>soil</sub> plot was used to estimate the capacities of the soil to adsorb Zn with specified affinities. The <span class=](/na101/home/literatum/publisher/tandf/journals/content/tssp20/1978/tssp20.v024.i03/00380768.1978.10433120/production/images/medium/tssp_a_10433120_o_ilf0002.gif)    | |
| Keywords: | selectivity coefficient K Zn Ca two-term Langmuir equation allophanic soil |
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