EDTA functionalized magnetic nanoparticle sorbents for cadmium and lead contaminated water treatment

Cadmium (Cd2+) and lead (Pb2+) are toxic to human beings and other organisms, and the U.S. Environmental Protection Agency (EPA) has classified both as probable human carcinogens. In this study, a regenerable magnetic ligand particle (Mag-Ligand) which includes a metal-binding organic ligand (EDTA) attached to an iron oxide nanoparticle was developed for rapid removal of Cd2+ and Pb2+ as well as other metals from contaminated water. Mag-Ligand showed fast removal ability for both Cd2+ (<2 h) and Pb2+ (<15 min) with relatively high sorption capacity (79.4 and 100.2 mg/g for Cd2+ and Pb2+, respectively). The removal performance of Mag-Ligand was high across a wide pH range (3-10) as well as in the presence of competitive metal ions (Ca2+ and Mg2+). In addition, Mag-Ligands can be easily regenerated (washed by 1% HCl) and reused several cycles with high sorption capacity. This study indicated that Mag-Ligand is a reusable sorbent for rapid, convenient, and efficient removal of Cd2+ and Pb2+ from contaminated aquatic systems. (C) 2015 Elsevier Ltd. All rights reserved.