Effects of oxygen on the adsorption/oxidation of aqueous Sb(III) by Fe-loaded biochar: An X-ray absorption spectroscopy study.

Autor: Dong Z; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Zhou J; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Huang T; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Yan Z; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Liu X; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Jia X; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Zhou W; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Li W; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Finfrock YZ; CLS@APS Sector 20, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA; Science Division, Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada., Wang X; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China., Liu P; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Rd., Wuhan, Hubei 430074, PR China. Electronic address: pengliu@cug.edu.cn.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Nov 10; Vol. 846, pp. 157414. Date of Electronic Publication: 2022 Jul 16.
DOI: 10.1016/j.scitotenv.2022.157414
Abstrakt: Fe-loaded biochar (FeBC) has been considered for Sb(III) adsorption, but the effects of oxygen (O 2 ) on the adsorption need further investigation. Liquid-/solid-phase analyses were conducted to investigate the role of O 2 in the Sb(III) adsorption by FeBC. The adsorption was best described by the pseudo-second-order (PSO) model for kinetic results and by the Langmuir model for thermodynamic results. More than 96.8 % of Sb(III) was adsorbed by FeBC, and available O 2 increased the liquid-phase Sb(III) oxidation efficiency by 2.1-7.5 times. The peak changes at ~1640 and 3450 cm -1 in FTIR spectra indicated the occurrence of inner-sphere complexation between Sb(III)/Sb(V) and hydroxyl (-OH)/carboxyl (-COOH) groups in FeBC under aerobic and anaerobic conditions. Fe/Sb X-ray absorption spectroscopy (XAS) analysis results showed aqueous Sb(III) complexed to the edge-sharing Fe(III)-O-Fe(III) in FeBC. Regardless of whether O 2 was available or not, solid-phase edge-sharing Fe(III)-O-Sb(V) complexes (~3.05 Å), which had lower toxicity and migration ability than aqueous Sb(III), formed through a ligand-to-metal charge-transfer (LMCT) process. More than 91 % of adsorbed Sb(III) was oxidized to edge-sharing Fe(III)-O-Sb(V) complexes in 3 h. Additionally, the Sb(V) from liquid-phase oxidation could also directly complex to the Fe(III)-O-Fe(III) and form edge-sharing Fe(III)-O-Sb(V) complexes. These results provide evidence to inform further FeBC application for the Sb-contaminated water treatment.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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