Fabrication of glycine-functionalized maghemite nanoparticles for magnetic removal of copper from wastewater

Maghemite nanoparticles (MNPs) were functionalized with glycine, by a cost-effective and environmentally friendly procedure, as an alternative route to typical amine-functionalized polymeric coatings, for highly efficient removal of copper ions from water. MNPs were synthesized by co-precipitation method and adsorption of glycine was investigated as a function of ligand concentration and pH. The efficiency of these functionalized nanoparticles for removal of Cu2+ from water has been explored and showed that adsorption is highly dependent of pH and that it occurs either by forming chelate complexes and/or by electrostatic interaction. The adsorption process, which reaches equilibrium in few minutes and fits a pseudo second-order model, follows the Langmuir adsorption model with a very high maximum adsorption capacity for Cu2+ of 625 mg/g. Furthermore, these nanoadsorbents can be used as highly efficient separable and reusable materials for removal of toxic metal ions.