Removal of Cd(II), Pb(II), Hg(II), Mn(II), Ni(II) and Zn(II) by chemically (Na2S) treated granular activated carbon (GAC)has been found to be concentration, pH, contact time, adsorbent dose and temperature dependent. Adsorption isotherm studiesindicated that adsorptive behaviour of metal ions on chemically treated GAC satisfies Langmuir assumptions. Proposed methodhad potential application for effluent treatment in industries.