Adsorptive removal of arsenic from aqueous solutions using magnetite nanoparticles and silica‐coated magnetite nanoparticles

Abstract

Magnetite nanosorbents are known with high sorption capacity and ease of solid phase separation from surrounding liquid by the imposed external magnetic field. In this study, magnetite nanoparticles (MNPs) and silica‐coated magnetite nanoparticles (Si‐MNPs) were prepared and used for the removal of arsenic (III) from aqueous solutions. The nanosorbents were characterized by transmission electron microscope, X‐ray diffraction, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. The spherical Fe3O4 nanoparticles in diameter of about 100 nm and SiO2 shells of 12 nm were formed. The saturation magnetization was found to be 78 and 58 e mug–1 for MNPs and Si‐MNPs, respectively. Under optimal conditions, both nanosorbents were very efficient for arsenite uptake (removal efficiency ≥99%). The highest removal percentage was obtained near PZC of nanosorbents where the net surface charge was zero. The MNPs exhibited higher sorption capacities in comparison with Si‐MNPs although they tended to be agglomerated in higher applied doses. The kinetic of experiments indicated the best fit to the pseudo‐second order model. Furthermore, the experimental data were best described by the Langmuir model. This study demonstrated the effectiveness of bare and silica coated magnetic nanoparticles to remove trace concentrations of arsenic (III) in water environment. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 951–960, 2018

Facile Synthesis of Silica Coated Magnetic Nanoparticles via Green Microwave-Solventless Technique for Purification of Water from Toxic Heavy Metals

“…Electrochemical treatments, flocculation and membrane filtration is a high cost techniques, process complexity, membrane fouling and low permeate flux. On the contrary, adsorption is an ideal technique to remove toxic pollutants from water for its simplicity, high efficiency, ease of operation, regeneration characteristics [3], and can remove heavy metals found in water at low concentrations [16]. Fortunately, the evolution of nanotechnology has highlighted this issue [2].…”

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“…However, the removal of nano-adsorbent from water solutions is difficult for the small size of these particles. So, magnetic nanoparticles overcome this defect by removing these nanoparticles (NPs) and hazardous elements magnetic properties change and biodegrade in biological systems, it was also found that the bare magnetic nano-adsorbent were exposed to oxidation and loss of its magnetic properties at pH lower than 4 [3]. So, coating of magnetic NPs with silica is a commonly used procedure to obtain magnetic sorbents; this is due to silica stability and versatility of its surface modification [6].…”

“…So, coating of magnetic NPs with silica is a commonly used procedure to obtain magnetic sorbents; this is due to silica stability and versatility of its surface modification [6]. Silica coated magnetic nanoparticles with a magnetic core and a silica shell has the advantages of both materials with no apparent effect on magnetic properties that characterize the nano-magnetite [3]. Using of this magnetic nano-adsorbent for removal of pollutants from water continues to progress nowadays.…”

Synthesis and application of Fe 3 O 4 @nanocellulose/TiCl as a nanofiller for high performance of quasisolid‐based dye‐sensitized solar cells

“…[38][39][40] This nanoparticle has been prepared by different methods such as precipitation, 41 electrooxidation, 42 and coprecipitation. 43 Because of being oxidized in an acidic medium 44 and formation of large aggregation, pure magnetic nanoparticles (Fe 3 O 4 -NP) are coated with different materials such as silica 45 and surfactants 46 to form a stabilized core-shell for further functionalization with various nanoparticles and ligands according to their application. 47 For the first time, in this work, the novel Fe 3 O 4 @NCs/ TiCl nanocomposite is introduced into gel-state polyvinyl acetate (PVAc)-based electrolyte as a nanofiller to decrease the crystallinity of the polymer, enhance the diffusion of redox couple ions, and prepare a nanocomposite gel electrolyte for quasisolid-state dye-sensitized solar cells (QS-DSSCs).…”