Abstract
This study was conducted for the efficient utilization of a scoria, which is abundantly found in Cheju island, as adsorbent and the scoria was examined for its performance in clarification of adsorption of heavy metal ions. The order in heavy metal ions adsorbed on scoria was; Pb+>Cd^{2+}$>Cu^{2+}$>Ag^+$>Co^{2+}$>Zn^{2+}$>Cr^{3+}$>Cr^{6+}$. This tendency was relatively consistent with the decreasing order of radius of hydrated metal ion. Also, the smaller scoria size and the larger amounts of scoria showed higher removal efficiency for heavy metal ions. The same scoria size showed more effective removal efficiency for heavy metal ions at lower initial concentration than at higher initial concentration. The adsorption abilities of original scoria and chemically treated scoria were compared. Adsorption isotherm of scoria was generally obeyed to Freundlich formula than langmuir formula and Freundlich constant, than was obtained in the range of 0.2~0.4.