Based on the previous results of the equilibrium and batch adsorptions, the removal efficiency of the two-step surface-modified activated carbon (2ndAC) for heavy metal ions such as Pb, Cd, and Cr in fixed column was evaluated by comparing with that of the as-received activated carbon (AC) and the first surface-modified activated carbon (1stAC). The order of metal removal efficiency was found as 2ndAC 〉 1stAC 》 AC, and the efficiency of the 2ndAC maintained over 98% from the each metal solution. Increase of the removal efficiency by the second surface modification was contributed to maintain favorable pH condition of bulk solution during adsorption process. The removal of the heavy metals on the 2ndAC was selective with Pb being removed in preference to Cr and Cd in multicomponent solutions and slightly influenced by phenol as the organic material.

• Jae-Kwang Lee(Dept. of Chemical Engineering, Chungnam National University)
• Geun-Il Park(Korea Atomic Energy Research Institute)
• Seung-Kon Ryu(Dept. of Chemical Engineering, Chungnam National University)
• Joon-Hyung Kim(Korea Atomic Energy Research Institute)