Adsorption of Cu2+ from aqueous solution by a novel material; azomethine functionalized magnetic nanoparticles

In this report, a novel functionalized magnetic nanoparticles (MNP-Maph) synthesized via covalent grafting of 4-{[(E)-phenylmethylidene]amino}benzoic acid (Maph-COOH) onto the surface of amine functionalized magnetic nanoparticles (MNP-NH2) was characterized and assessed for the removal of heavy metal ion Cu2+ from aqueous solution by adsorption. To afford MNP-Maph, Maph-COOH was first synthesized and covalently linked to MNP-NH2. FTIR and XRD analysis showed that MNP-Maph was successfully synthesized while TEM and XRD results revealed that the average size of the synthesized particles were in the range of 18 ± 5 nm. Time-dependent adsorption studies conducted at pH 5 showed that Cu2+ removal by MNP-Maph attained equilibrium within 45 min at different initial adsorbate concentrations and favoured pseudo second-order kinetic model. MNP-Maph showed remarkable sorption uptake (qe) of Cu2+ as adsorbate temperature increases from 293 to 318 K and Langmuir isotherm best describes the adsorption process. Thermodynamic study revealed the spontaneity and randomness of the adsorption process. Regenerability experiment indicates that MNP-Maph exhibit excellent adsorption/desorption efficiency and will be good for re-use. Importantly, MNP-Maph was found to effectively and selectively remove Cu2+ from domestic and industrial wastewater containing multiple ions and organic contaminants, suggesting that MNP-Maph can serve as a potential and promising adsorbent for the removal of Cu2+ from wastewater.