Rapid and highly selective removal of lead in simulated wastewater of rare-earth industry using diglycolamic-acid functionalized magnetic chitosan adsorbents

Rapid and highly selective magnetic core–shell adsorbents for Pb 2+ removal from simulated wastewater of rare-earth industry were prepared by synthesizing chitosan-coated Fe 3 O 4 (Fe@CS) beads and following chemical-grafting steps for the diglycolamic-acid group (DGA). The adsorbents had a highly selective ability for Pb 2+ toward other metal ions, which attributed to the superior infinity between the DGA and Pb 2+ . The maximum adsorption capacity of Pb 2+ was 70.57   mg/g. The R 2 of the pseudo-second order kinetics was 0.99857, which indicated the adsorption process was controlled by chemical reactions. Moreover, diglycolamic-acid functionalized Fe@CS (Fe@CS-DGA) beads separated from water within 9   s under magnetic fields.