Simultaneous removal of Pb(II), Cd(II) and bacteria from aqueous solution using amino-functionalized Fe₃O₄/NaP zeolite nanocomposite

ABSTRACT

Fe₃O₄/NaP nanocomposite was synthesized and modified using 3-aminopropyltrimethoxysilane (3-APTS)-functionalization. Fe₃O₄/NaP/NH₂ was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, elemental analysis, energy-dispersive X-ray analysis, vibrating sample magnetometer, Brunauer-Emmett-Teller and thermogravimetric analysis techniques. Batch adsorption studies of Pb(II) and Cd(II) on Fe₃O₄/NaP/NH₂ were investigated. The effect of experimental parameters (including pH, adsorbent dose, heavy metals’ concentration, adsorption time and temperature) was studied. The results indicated that Fe₃O₄/NaP/NH₂ have a high removal percent for Pb(II) and Cd(II) (more than 95%). The metal-loaded Fe₃O₄/NaP/NH₂ nanocomposite could be recovered from the aqueous solution by magnetic separation and regenerated easily by acid treatment. The experimental data were fitted to Langmuir, Freundlich and Dubinin–Kaganer–Radushkevich (DKR) isotherm models. The Langmuir equation showed a better correlation with the experimental data than the other two models. The adsorption kinetics data were found to follow the pseudo-second-order kinetic model for Pb(II) and pseudo-first-order for Cd(II). The thermodynamic parameters (ΔG, ΔH and ΔS) were measured and the negative value of Gibbs energy indicated that the adsorption process was spontaneous in nature. The in vitro antibacterial activity of Fe₃O₄/NaP/NH₂ composites before and after removal of metals show good inhibition on bacterial growth against Bacillus subtilis (as Gram-positive bacteria) and Pseudomonas aeruginosa (as Gram-negative bacteria), and the antibacterial activity of it comparison with standard drugs.

GRAPHICAL ABSTRACT

KEYWORDS:

• Fe₃O₄/NaP/NH₂ nanocomposite
• functionalization
• Pb(II)
• Cd(II)
• removal of heavy metals
• antibacterial activity

Acknowledgements

Thanks are due to the Iranian Nanotechnology Initiative and the Research Council of Arak University of Technology and Center of Excellence in the Chemistry Department of Arak University of Technology for supporting this work.

Disclosure statement

No potential conflict of interest was reported by the authors.