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Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic

Nanoscale Zero-Valent Iron (nZVI) is a cost-effective nanomaterial that is widely used to remove a broad range of metal(loid)s and organic contaminants from soil and groundwater. In some cases, this material alters the taxonomic and functional composition of the bacterial communities present in thes...

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Autores principales: Castaño, Ana, Prosenkov, Alexander, Baragaño, Diego, Otaegui, Nerea, Sastre, Herminio, Rodríguez-Valdés, Eduardo, Gallego, José Luis R., Peláez, Ana Isabel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8010140/
https://www.ncbi.nlm.nih.gov/pubmed/33815330
http://dx.doi.org/10.3389/fmicb.2021.643589
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author Castaño, Ana
Prosenkov, Alexander
Baragaño, Diego
Otaegui, Nerea
Sastre, Herminio
Rodríguez-Valdés, Eduardo
Gallego, José Luis R.
Peláez, Ana Isabel
author_facet Castaño, Ana
Prosenkov, Alexander
Baragaño, Diego
Otaegui, Nerea
Sastre, Herminio
Rodríguez-Valdés, Eduardo
Gallego, José Luis R.
Peláez, Ana Isabel
author_sort Castaño, Ana
collection PubMed
description Nanoscale Zero-Valent Iron (nZVI) is a cost-effective nanomaterial that is widely used to remove a broad range of metal(loid)s and organic contaminants from soil and groundwater. In some cases, this material alters the taxonomic and functional composition of the bacterial communities present in these matrices; however, there is no conclusive data that can be generalized to all scenarios. Here we studied the effect of nZVI application in situ on groundwater from the site of an abandoned fertilizer factory in Asturias, Spain, mainly polluted with arsenic (As). The geochemical characteristics of the water correspond to a microaerophilic and oligotrophic environment. Physico-chemical and microbiological (cultured and total bacterial diversity) parameters were monitored before and after nZVI application over six months. nZVI treatment led to a marked increase in Fe(II) concentration and a notable fall in the oxidation-reduction potential during the first month of treatment. A substantial decrease in the concentration of As during the first days of treatment was observed, although strong fluctuations were subsequently detected in most of the wells throughout the six-month experiment. The possible toxic effects of nZVI on groundwater bacteria could not be clearly determined from direct observation of those bacteria after staining with viability dyes. The number of cultured bacteria increased during the first two weeks of the treatment, although this was followed by a continuous decrease for the following two weeks, reaching levels moderately below the initial number at the end of sampling, and by changes in their taxonomic composition. Most bacteria were tolerant to high As(V) concentrations and showed the presence of diverse As resistance genes. A more complete study of the structure and diversity of the bacterial community in the groundwater using automated ribosomal intergenic spacer analysis (ARISA) and sequencing of the 16S rRNA amplicons by Illumina confirmed significant alterations in its composition, with a reduction in richness and diversity (the latter evidenced by Illumina data) after treatment with nZVI. The anaerobic conditions stimulated by treatment favored the development of sulfate-reducing bacteria, thereby opening up the possibility to achieve more efficient removal of As.
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spelling pubmed-80101402021-04-01 Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic Castaño, Ana Prosenkov, Alexander Baragaño, Diego Otaegui, Nerea Sastre, Herminio Rodríguez-Valdés, Eduardo Gallego, José Luis R. Peláez, Ana Isabel Front Microbiol Microbiology Nanoscale Zero-Valent Iron (nZVI) is a cost-effective nanomaterial that is widely used to remove a broad range of metal(loid)s and organic contaminants from soil and groundwater. In some cases, this material alters the taxonomic and functional composition of the bacterial communities present in these matrices; however, there is no conclusive data that can be generalized to all scenarios. Here we studied the effect of nZVI application in situ on groundwater from the site of an abandoned fertilizer factory in Asturias, Spain, mainly polluted with arsenic (As). The geochemical characteristics of the water correspond to a microaerophilic and oligotrophic environment. Physico-chemical and microbiological (cultured and total bacterial diversity) parameters were monitored before and after nZVI application over six months. nZVI treatment led to a marked increase in Fe(II) concentration and a notable fall in the oxidation-reduction potential during the first month of treatment. A substantial decrease in the concentration of As during the first days of treatment was observed, although strong fluctuations were subsequently detected in most of the wells throughout the six-month experiment. The possible toxic effects of nZVI on groundwater bacteria could not be clearly determined from direct observation of those bacteria after staining with viability dyes. The number of cultured bacteria increased during the first two weeks of the treatment, although this was followed by a continuous decrease for the following two weeks, reaching levels moderately below the initial number at the end of sampling, and by changes in their taxonomic composition. Most bacteria were tolerant to high As(V) concentrations and showed the presence of diverse As resistance genes. A more complete study of the structure and diversity of the bacterial community in the groundwater using automated ribosomal intergenic spacer analysis (ARISA) and sequencing of the 16S rRNA amplicons by Illumina confirmed significant alterations in its composition, with a reduction in richness and diversity (the latter evidenced by Illumina data) after treatment with nZVI. The anaerobic conditions stimulated by treatment favored the development of sulfate-reducing bacteria, thereby opening up the possibility to achieve more efficient removal of As. Frontiers Media S.A. 2021-03-17 /pmc/articles/PMC8010140/ /pubmed/33815330 http://dx.doi.org/10.3389/fmicb.2021.643589 Text en Copyright © 2021 Castaño, Prosenkov, Baragaño, Otaegui, Sastre, Rodríguez-Valdés, Gallego and Peláez. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Castaño, Ana
Prosenkov, Alexander
Baragaño, Diego
Otaegui, Nerea
Sastre, Herminio
Rodríguez-Valdés, Eduardo
Gallego, José Luis R.
Peláez, Ana Isabel
Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic
title Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic
title_full Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic
title_fullStr Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic
title_full_unstemmed Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic
title_short Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic
title_sort effects of in situ remediation with nanoscale zero valence iron on the physicochemical conditions and bacterial communities of groundwater contaminated with arsenic
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8010140/
https://www.ncbi.nlm.nih.gov/pubmed/33815330
http://dx.doi.org/10.3389/fmicb.2021.643589
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