High efficiency activated carbon with different chemical characteristics, appropriate for the purification of waste and potable water with different pollutions (metal ions) was prepared. It was established that activated carbon is obtained from carbonized olive stones in presence of nitrogen in the temperature range from 700 to 800°C and activated by ZnCl2 and KOH. The pore structure of the activated carbon was characterized by CO2 adsorption at 273 K and by N2 adsorption at 77 K. B.E.T and Dubinin equations were used to deduce the effective surface area. Micro and mesoporosity have been measured by immersion calorimetry. The prepared activated carbon has very large surface area as well as highly developed microporosity. Experimental conditions for the preparation of the active carbon, highly microporous but with well developed mesoporosity, are discussed. Activated carbon prepared from olive stones can be used for Pb2+ ions removal from potable water in the presence of other metal ions and found that NaCl will interfere in adsorption. The sample activated by KOH has the highest adsorption capacity followed by ZnCl2. The high concentration of active sites on the surface of the carbon from olive stones activated by KOH might have facilitated the adsorption of metal ions.