Activated carbon (AC) derived from waste coconut buttons (CB) was investigated as a suitable adsorbent for the removal of heavy
metal ions such as Pb(II), Hg(II) and Cu(II) from industrial effluents through batch adsorption process. The AC was characterized by
elemental analysis, fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermal gravimetric and
differential thermal analysis, surface area analyzer and potentiometric titrations. The effects of initial metal concentration, contact time,
pH and adsorbent dose on the adsorption of metal ions were studied. The adsorbent revealed a good adsorption potential for Pb(II) and
Cu(II) at pH 6.0 and for Hg(II) at pH 7.0. The experimental kinetic data were a better fit with pseudo second-order equation rather than
pseudo first-order equation. The Freundlich isotherm model was found to be more suitable to represent the experimental equilibrium
isotherm results for the three metals than the Langmuir model. The adsorption capacities of the AC decreased in the order: Pb(II) >
Hg(II) > Cu(II).