This paper deals with the treatment of wastewater released from petroleum industry by using clay and activated carbon as adsorbents for removal of heavy metals. A filled column of clay and activated carbon was used for a continuous flow system and a sample collector was used to monitor the removal efficiency. The optimum treatment conditions were explored. The removal efficiencies of the heavy metal cations were found to be 55, 64, 75, 57, 63, and 82% for Pb, Cu, As, Co, Ni and Cr, respectively. After a second cycle of treatment, the removal efficiency was significantly increased. The removal efficiencies for the pretreated industrial samples were found to be 90, 99, 100, 100, 95 and 100 % for Cu, As, Co, Ni, Pb and Cr, respectively. These results indicate that the employed adsorbent mixture has a huge potential in the application as efficient adsorbent for removal of cationic heavy metal species from industrial wastewater.