AbstractThis study investigated the adsorption of the heavy-metal ions Cu(II) and Pb(II) onto a lignin derivative. The lignin derivative was obtained by treating bagasse soda lignin with epichlorohydrin, and subsequently grafting an amine functional group by the Mannich reaction. The morphology of aminated epoxy-lignin was a layered structure with pores characterized by SEM. The heavy-metal ion adsorption data could be described well with the pseudo-first order model for Pb(II) ion and the pseudo-second order model for Cu(II) ion; diffusion was found to be the rate-limiting step when approaching equilibrium. FTIR spectroscopy was used to study the mechanism of heavy-metal adsorption by the derivatized lignin. The results show that the sites for adsorption are related to hydroxyl and amido groups.