Application of three types of aminated lignins for efficient removal of Cd(II) and Pb(II) ions in aqueous solution

Lignin is a renewable natural aromatic polymer that generated as co-product during lignocellulosic biorefinery processes, and it has been applied widely functional biomaterial. In this study, the adsorption behavior of Cd(II) Pb(II) metal ions was investigated via ion chelation using aminated lignins (ALs) with primary, secondary, tertiary amine groups. ALs exhibited optimal capacities in solution under neutral conditions due to their chelating, electrostatic, cationic–? interactions ions. The AL primary group showed highest for both Pb(II), reaching 83.2 159.7 mg·g-1, respectively, followed by secondary kinetics isotherm analysis demonstrated all behaviors Langmuir pseudo-second-order kinetics. Thermodynamic studies revealed processes were spontaneous endothermic. These results demonstrate are promising adsorbents removal