Modified Granular Activated Carbon of grade F300, has been used as an adsorbent material for the removal of nickel (II) from aqueous solutions at different experimental conditions in batch adsorption technique. F 300 GAC was modified with Nitric acid.GAC was characterized by SEM and AAS techniques. The time required to attain equilibrium was found to be 6 hrs. The effects of initial concentration of Ni (II), particle size of adsorbent, adsorbent dose and temperature on removal of nickel (II) have been studied. The Ni2+ content of the solution was analyzed by colorimetric. Nitric acid modified GAC shows higher adsorption capacity. Batch adsorption kinetics has been described by the Langmuir equation. Langmuir and Freundlich isotherms were applied and both isotherms were seen to be applicable over the concentration range studied.