Properties and mechanism of Cr(VI) adsorption and reduction by K2FeO4 in presence of Mn(II). Issue 6 (8th March 2022)

• Record Type: Journal Article
• Authors: Xu, Liang; Fu, Fenglian; Yu, Peijing; Sun, Guangzhao
• Is Part Of: Environmental technology. Volume 43:Issue 6(2022)
• Page Start: 918
• Page End: 926
• Publication Date: 2022-03-08
• Subjects: K2FeO4 -- Cr(VI) adsorption -- Fe(VI) reduction products -- MnOx -- mechanism; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2020.1811392
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: To efficiently treat hexavalent chromium (Cr(VI)) wastewater, K2 FeO4 was used to remove and reduce Cr(VI) in presence of Mn(II) in this paper. Batch removal experiments were carried out to study the effect of Fe/Mn molar ratios, initial pH, in-situ and ex-situ and co-existing ions on Cr(VI) removal. The results showed the removal efficiency of Cr(VI) was 97.7% for the initial Cr(VI) concentration of 10.0 mg/L at Fe/Mn molar ratio of 2:3 and initial pH 8.0. Meanwhile, the high removal efficiency of Cr(VI) had been maintained throughout the pH range of 3.0–8.0 in the experimental study. Moreover, the removal process was relatively stable regardless of in-situ and ex-situ, and co-existing ions such as Ca 2+ and low concentration of HCO 3 − had no intense effect on Cr(VI) removal, while SO 4 2 − inhibited Cr(VI) removal in the reaction system. To investigate the removal mechanism of Cr(VI) by K2 FeO4 in presence of Mn(II), the reaction products were characterized by the Fourier transformed infrared spectrometer, X-ray powder diffraction, Transmission electron microscopy and the high-resolution X-ray photoelectron spectroscopy. The results indicated the ferrate decomposition products of γ-FeOOH/γ-Fe2 O3 had the ability to adsorb Cr(VI) and react with Mn(II) to form γ-Fe2 O3 -Mn(II) complex to adsorb and reduce Cr(VI). GRAPHICAL ABSTRACT: UF0001