The removal of heavy-metal ions from aqueous water containing 100ppm of Pb^<2+> or Cd^<2+> was investigated using Loy Yang brown coal pre-treated by the following three-stage process: (i) loading of divalent cations by ion-exchange method, (ii) heat-treatment at 300℃ for 5h, and (iii) acid-washing. The exchanged amount of Pb^<2+> and Cd^<2+> from 100ppm solution of pH 6 was about 96-97% using non-treated sample. In the case of the samples treated with Ca^<2+> or Zn^<2+>, the exchanged amount of Pb^<2+> was kept almost the same as the non-treated sample, while the exchanged amount of Cd^<2+> was reduced to only 30%.
