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Synthesis of Fe3O4-loaded porous carbons developed from rice husk for removal of arsenate from aqueous solution
Luo, S.; Shen, M.-N.; Wang, F.; Zeng, Q.-R.; Shao, J.-H. & Gu, J.-D.
Abstract
A simple one-step synthetic approach using
rice husk has been developed to prepare magnetic Fe3O4-loaded porous carbons composite (MRH) for removal of
arsenate (As(V)). The characteristics of adsorbent were
evaluated by transmission electron microscope, scanning
electron microscopy, X-ray diffraction, Fourier transform
infrared spectroscopy, Brunauer–Emmett–Teller analysis,
and thermogravimetric analysis. On account of the combined
advantages of rice husk carbons and Fe3O4
nanoparticles, the synthesized MRH composites showed
excellent adsorption efficiency for aqueous As(V). The
removal of As(V) by the MRH was studied as a function of
contact time, initial concentration of As(V), and media pH.
The adsorption kinetics of As(V) exhibited a rapid sorption
dynamics by a pseudo-second-order kinetic model,
implying the mechanism of chemisorption. The adsorption
data of As(V) were fitted well to the Langmuir isotherm
model, and the maximum uptake amount (qm) was
calculated as 4.33 mg g-1. The successive regeneration
and reuse studies showed that the MRH kept the sorption
efficiencies over five cycles. The obtained results demonstrate
that the MRH can be utilized as an efficient and low-cost
adsorbent for removal of As(V) from aqueous
solutions.
Keywords
Adsorption; Carbon; Characterization; Langmuir; Magnetic material
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