Abstract

Maize cob carbon was prepared by pyrolysis at 300 and 400^oC for 35 min. This was followed by steeping in saturated ammonium chloride. The activated carbon which was characterized for bulk density, surface area, surface area charge, abrasion resistance and pH was used in the removal of Cd²⁺, N₁²⁺, Cd²⁺ and Zn²⁺. The surface areas of the maize cob carbon at 300 and 400^oC were 0.010 and 0.021 g sample per mg iodine, respectively. The effectiveness of the modified maize cobs in removing the metal ions from solution was found to be Zn >Ni> Cd. The removal efficiency of the metal ions is depended on the metal ion concentration and temperature of carbonization. 

Key words: Maize cobs, activated carbon, pyrolysis, steeping,carbonization.