Highly efficient removal of Pb(II) from aqueous systems using a new nanocomposite: Adsorption, isotherm, kinetic and mechanism studies

Abstract

In this research, amino-guanidinopentanoic acid (AGPA) functionalized benzene dicarboxylic coated magnetic nanoparticles (Fe3O4@BDC) was synthesized (Fe3O4@BDC@AGPA) by in situ co-precipitation process for removal of toxic Pb(II) ions from aqueous environment. The Fe3O4@BDC@AGPA nanocomposite was characterized by various instrumental technique viz., Fourier-transform infrared spectroscopy, X-ray diffraction, zeta potential, thermogravimetric analysis, energy-dispersive, and transmission electron microscopy, The effect of various parameters such as contact time, adsorbent dose, pH solution, initial Pb(II) concentration and temperature on the adsorption capacity of Pb(II) by the Fe3O4@BDC@AGPA nanocomposite was achieved. The results reveal that the adsorption process conforms to Langmuir adsorption isotherm models and the pseudo-second-order kinetic. The maximum Pb(II) adsorption capacity of Fe3O4@BDC@AGPA was 157 mg/g at condition factors min (Co– 300 mg/L; pH– 5.6; adsorbent dosage- 20 mg; temperature– 25 °C). After Pb(II) ions removal, Fe3O4@BDC@AGPA were separated using external magnetic field from aqueous medium and efficiently regenerated using 0.01 M HCl eluting. The percentage of leaching of iron in both adsorbents Fe3O4 and Fe3O4@BDC@AGPA in 0.01 M HCl for 24 h were 6.32% and 0.01%, respectively which indicating the good stability under acidic condition. The Fe3O4@BDC@AGPA possessed excellent regenerative performance after five cycles.