Activated carbon has been prepared from sewage sludge of the municipal wastewater treatment plant using chemical activation method. Porous structure of activated carbon was characterized by nitrogen adsorption and scanning electron microscopy. It was also characterized by its surface area and porosity. Its surface is an irregular and porous structure. Then it was used as an adsorbent for the removal of nickel ions from aqueous solution. The effects of parameters such as contact time and initial nickel ion concentration were investigated. The adsorption kinetics of nickel ions in aqueous solution onto activated carbon was investigated through experimental data. The results showed that the adsorption process was perfectly fitted to the pseudo-second order model with very high regression coefficient. It may be evaluated as an environmental friendly and extra economic treatment of nickel ions in aqueous solution.