The Adsorption Characteristics and the Separation and

Abstract

The characteristics of the static and dynamic adsorption of cobalt(II) ion on silica gel were studied in order to clarify the adsorption mechanism and to obtain the basic data for the separation of this harmful ion from waste water. At high cobalt(II) ion concentration, one cobalt ion exchanged adout two protons of free silanol groups on the surface. At concentrations below several ppm, it was found that 60 to 90% of cobaltOn ions was adsorbed at pH higher than 6, and that cobalt(II) ions were removed almost completely by dynamic adsorption chromatography. The resolution of these adsorbed ions into water was markedly suppressed by sintering the adsorbent after the adsorption. These results indicate the possibility of efficient and economical separation and fixation of such harmful ions as cobalt(II) ion from waste water.