Iron-modified biochar-based bilayer permeable reactive barrier for Cr(VI) removal.

Autor: Zhou Z; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China., Liu P; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China. Electronic address: pengliu@cug.edu.cn., Wang S; Zhejiang Geological Prospecting Institute, China Chemical Geology and Mine Bureau, Hangzhou 310000, China., Finfrock YZ; Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, IL 60439, USA., Ye Z; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China., Feng Y; School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China., Li X; China Northeast Municipal Engineering Design and Research Institute Co., Ltd., Changchun 130021, China.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2022 Oct 05; Vol. 439, pp. 129636. Date of Electronic Publication: 2022 Jul 19.
DOI: 10.1016/j.jhazmat.2022.129636
Abstrakt: Iron (Fe)-modified biochar (FeBC) has been developed to remove hexavalent chromium (Cr(VI)) from groundwater and is suitable for use in permeable reactive barriers (PRBs). However, Cr(VI) removal behavior and chemical processes in FeBC-based PRBs are not fully understood, and the potential for Fe release has not been addressed. In this study, three FeBC-based PRBs were assessed in column experiments for 563 days with respect to their ability to remove Cr(VI). Bilayer column filled with FeBC+limestone and BC+limestone in two separate layers (FeBC_Ca_BC) showed the best performance in terms of Cr(VI) removal with a low treatment cost. The corrosion of FeBC was mainly related to pH and Cr(VI) concentration rather than flow rate. Leached Fe was attenuated by BC and limestone and reutilized in FeBC_Ca_BC. Cr(VI) was reduced to Cr(III) and then adsorbed or precipitated on the biochars. Cr and Fe formed inner-sphere complexes and then transformed from double corner sharing to edge sharing. During the reaction, Cr penetrated from the surface to the interior of the biochars and became a more stable species. This study provides evidence of the effectiveness of a new combination of biochars for Cr(VI) removal and insights into the reaction mechanisms.
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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