Sorption of certain heavy-metal ions by hydrolyzed lignin and its derivatives

The ability to form intermolecular coordination of lignin macromolecules and metal ions through both ionic and coordinative metal—ligand bonds was shown by studying the sorption activity of hydrolyzed lignin from cotton seed husks (HLCSH) and its aminated derivatives. The studied lignins exhibited high sorption activity for metal ions over the whole range of concentrations used. The heavy-metal ions fell in the following order of decreasing lignin sorption activity: Fe > Pb > Cu > Cd > Zn.