Abstract
The hydrous oxides of metallic elements adsorb ions. In this study, ten Si-Fe-Mg mixed hydrous oxide samples were synthesized using various Si, Fe (III) and Mg molar ratios, and the adsorption properties of these samples were evaluated in terms of ion adsorption rate. The adsorption rate was high for most samples, and uptake occurred at the adsorption equilibrium for 24 hours. In particular, sample No. 10, for which the molar ratio of the metallic elements was Si : Fe : Mg = 0.1 : 0.1 : 0.8, which is the ratio with the highest of Mg, had adsorbed large amounts of arsenite and phosphate ions. The adsorption isotherms for fluorine, boron, arsenate, arsenite, phosphate, selenate and selenite ions had various various correspondences to the equation of Freundlich. Because the gradient of the equations was 0.1 - 0.5, sample No. 10 could adsorb from low and high concentrations of harmful ions easily.
