US EPA

7011067 

Journal Article 

The preparation of a novel iron/manganese binary oxide for the efficient removal of hexavalent chromium [Cr(vi)] from aqueous solutions 

Yang, C; Shi, X; Wang, W; Fan, Y; Ju, T; Wang, X; Ji, Y; Yang, C; Lv, H; Wang, Y; Dong, W; Dang, F; , 

2020 

1 

RSC Advances
EISSN: 2046-2069 

ROYAL SOC CHEMISTRY 

CAMBRIDGE 

10 

18 

10612-10623 

10.1039/c9ra10558a 

WOS:000524498100025 

To remove hexavalent chromium Cr(vi) efficiently, a novel Fe-Mn binary oxide adsorbent was prepared via a "two-step method" combined with a co-precipitation method and hydrothermal method. The as-prepared Fe-Mn binary oxide absorbent was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectra (FTIR), thermogravimetric analysis (TGA), zeta potential, BET and X-ray photoelectron spectroscopy (XPS). The results indicated that the morphology of the adsorbent was rod-like with length of about 100 nm and width of about 50-60 nm, specific surface area was 63.297 m(2) g(-1), has the composition of alpha-Fe2O3, beta-MnO2 and MnFe2O4 and isoelectric point was observed at pH value of 4.81. The removal of Cr(vi) was chosen as a model reaction to evaluate the adsorption capacity of the Fe-Mn binary oxide adsorbent, indicating that the Fe-Mn binary oxide adsorbent showed high adsorption performance (removal rate = 99%) and excellent adsorption stability (removal rate > 90% after six rounds of adsorption). The adsorption behavior of the Fe-Mn binary oxide was better represented by the Freundlich model (adsorption isotherm) and the pseudo-second-order model (adsorption kinetic), suggesting that the adsorption process was multi-molecular layer chemical adsorption. The possible adsorption mechanism of the Fe-Mn binary oxide for the removal of Cr(vi) included the protonation process and the electrostatic attraction interactions.