| Abstract |
| La(Ⅲ)-impregnated mesoporous silica(La-MS) adsorbent has been developed for the removal of F and P ions by adsorption. These adsorbent have been characterized by zeta potential, XRD and SEM analysis. To elucidate the surface characteristic of adsorbent, the zeta potentials were measured. As a result of zeta potential data, mesoporous silica(MS) indicated that the surface potentials seem to be dependent on the pH and the -15∼-55㎷ showed in the range of all pH. Otherwise, the surface potentials of La-MS indicated that the +50∼-40㎷ charge at the range of all pH. La-MS was tested for the removal of F and P ions from aqueous solution. Experiments were carried out as a function of pH and anion concentration in aqueous phase. The equilibrium time was 120min and equilibrium experiment data obeyed the pseudo second order kinetic model. The Langmuir model and Temkin model represented the experimental data as well. The maximum adsorption capacity of F and P ions calculated from Langmuir isotherm model was 22.24㎎/g and 23.86㎎/g, respectively. From calculated Temkin constant(B=2.857∼3.503J/㏖), this adsorption process is physical adsorption. The mechanism of the adsorption process showed that adsorption was dependent on intra particle diffusion model according to two step diffusion. To estimated thermodynamic parameters(△H0, △S0 and △G0) indicated that the adsorption was spontaneous and endothermic. The removal selectivity by La-MS was in order by F < P. |
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| Key Words |
| La(Ⅲ)-Impregnated mesoporous silica, adsorption, zeta potential, Langmuir model, kinetic model, thermodynamics |
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