Selective Recovery of Metal Ions Based on Selective Sinking of Zeolite Modified with Octadecyl and Diethylenetriamine Groups

Zeolite modified with octadecyl and diethylenetriamine groups (ZOD), which floats on surface of water, sinks into the water via the formation of metal–ligand complex, owing to the increase in hydrophilicity. The degree of the sinking depends on the metal ions coordinated, allowing selective recovery of ZOD particles loading high concentration of specific metal ion.