Microbial antimonate reduction with a solid-state electrode as the sole electron donor: A novel approach for antimony bioremediation

•Microbial Sb(V) reduction with solid electrode as electron donor was achieved.•The optimal biocathode potential for Sb(V) reduction was −0.7 V.•Sb(V) reduction switches to H2 evolution if cathode potential is more negative.•Both amorphous and crystallized Sb2O3 was detected as the reduced products....

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Bibliographic Details
Published in:Journal of hazardous materials 2019-09, Vol.377, p.179-185
Main Authors: Nguyen, Van Khanh, Park, Younghyun, Lee, Taeho
Format: Article
Language:English
Subjects:
Bioelectrochemical systems
Electrode potential
Microbial communities
Next-generation sequencing
Sb(V)-reduction
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Summary:•Microbial Sb(V) reduction with solid electrode as electron donor was achieved.•The optimal biocathode potential for Sb(V) reduction was −0.7 V.•Sb(V) reduction switches to H2 evolution if cathode potential is more negative.•Both amorphous and crystallized Sb2O3 was detected as the reduced products.•Chryseobacterium sp. and Stenotrophomonas sp. dominated Sb(V)-reducing biocathode. The anaerobic antimonate [Sb(V)] reduction with a solid-state electrode serving as the sole electron donor was demonstrated by employing a bioelectrochemical system. The highest Sb(V) reduction efficiency was observed at the biocathode potential of −0.7 V versus standard hydrogen electrode using a cathode potential range from −0.5 V to −1.1 V. The scanning electron microscopy and energy dispersive X-ray spectroscopy indicated that both amorphous and crystallized Sb2O3 were formed as products of Sb(V) reduction. The irreversible recovery of bioelectrochemical Sb(V), when the cathode potential deviated from the optimal potential, was explained through the alteration in microbial communities, which was further elucidated by the next-generation sequencing of 16S rRNA gene amplicons. Chryseobacterium koreense and Stenotrophomonas nitritireducens were the dominant species of microbial consortia at Sb(V)-reducing biocathodes. This study revealed a novel option for bioremediation of Sb at underground contaminated sites, where the delivery of organic electron donors is limited or ineffective.
ISSN:0304-3894
1873-3336
DOI:10.1016/j.jhazmat.2019.05.069