Adsorption of Mercury (II) Metal from Aqueous Solutions by Amine-Functionalized Magnetic Nano-particles

Nowadays, pollution of aquatic ecosystems with toxic metals, especially mercury, is one of the major concerns of the world. The use of nano-adsorbents is a novel high-performance method for removing heavy metals from aqueous media. In this study, in order to remove of Hg (II) from aqueous solutions and chloro-alkali wastewater, amine functionalized-Fe3O4@SiO2-NH2 nanocomposite was synthesized.

As-synthesized nano-composite was characterized by thermo-gravimetric analysis, scanning electron microscopy, Fourier Transform Infrared spectroscopy, and vibrating sample magnetometry. The nano-composite was used for removal of Hg (II) ions from aqueous solution and chloro-alkali wastewater in batch system.

The maximum equilibrium adsorption capacities for Hg (II) ions from aqueous solution 137.45 mg/g were calculated. Percentage of mercury removal from real wastewater was estimated about 55%. Sorption of Hg (II) ions with Fe3O4@SiO2-NH2 agreed well to the Langmuir isotherm model, confirming a monolayer adsorption. Desorption study showed that adsorbed metals could easily be desorbed from the adsorbent by 0.8 M HCl for Hg(II) ions, that the desorption percentage efficiencies was reduced from first to fifth cycle times about 15 %.

The results showed that the synthesized nanocomposite in this research has a relatively high adsorption capacity for Hg (II) ions adsorption, also according to its recyclability and reusability, the application of this adsorbent in wastewater treatment system could be reasonable in terms of the economic aspect.