Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5358413 | Applied Surface Science | 2014 | 8 Pages |
Abstract
In this study, Fe3O4 nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe3O4 NPs for engineering applications. The obtained EDA-Fe3O4 NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe3O4 NPs had a crystalline structure with a particle size range of 20-50Â nm and a BET surface area of 28Â m2Â gâ1. Functionalization with EDA was able to improve the adsorption selectivity of Fe3O4 for Cr(VI) in Cr(VI)/Clâor Cr(VI)/SO42â double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe3O4 NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe3O4 NPs retained a high adsorption capacity after several consecutive adsorption-desorption processes, indicating that EDA-Fe3O4 NPs serve as an excellent regenerable adsorbent for Cr(VI).
Keywords
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
X.B. Fang, Z.Q. Fang, P.K.E. Tsang, W. Cheng, X.M. Yan, L.C. Zheng,