In-situ chemical deposition as a new method for the preparation of Fe3O4 nanopaeticles embedded on anodic aluminum oxide membrane (Fe3O4@AAO): Characterization and application for arsenic removal using response surface methodology

Abstract

In the present work, a novel modified Fe3O4@AAO nanocomposite membrane was synthesized via the anodization of Al sheets and in-situ chemical deposition of Fe3O4 nanoparticles through a hydrothermal method. The Fe3O4 nanoparticles were arranged regularly and uniformly on the surface and also inside the pores. The membrane modification was confirmed by transmission electron microscopy, field emission scanning electron microscopy, energy dispersive X-ray Spectroscopy, element mapping images, fourier transform infrared spectroscopy and X-ray diffraction. The synthesized nanocomposite membrane was applied as an adsorbent for the arsenic removal from the aqueous media. The effective parameters for arsenic removal including pH, the initial concentration of arsenic and the removal time were investigated and optimized using central composite design and response surface methodology. Maximum arsenic removal was obtained under optimum conditions including pH: 6, initial arsenic concentration: 350 μg L–1 and removal time: 40 min. The behavior of arsenic adsorption was studied by isotherm models that the equilibrium results well fitted with the linear Langmuir isotherm model. The maximum removal capacity of As (V) as calculated from the linear Langmuir isotherm was 83.3 mg g–1. Also, The kinetics of the adsorption process follows by the linear pseudo-first-order model with higher R2 (0.9878). Thermodynamic results showed that the adsorption of As (V) on Fe3O4@AAO membrane was a spontaneous, endothermic and feasible process. The obtained results from real samples showed that the synthesized membrane has the excellent ability to remove As (V) from the aqueous media.