Electro-bioremediation of nitrate and arsenite polluted groundwater
dc.contributor.author
dc.date.accessioned
2021-01-26T09:08:12Z
dc.date.available
2021-01-26T09:08:12Z
dc.date.issued
2021-02-15
dc.identifier.issn
0043-1354
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dc.description.abstract
The coexistence of different pollutants in groundwater is a common threat. Sustainable and resilient technologies are required for their treatment. The present study aims to evaluate microbial electrochemical technologies (METs) for treating groundwater contaminated with nitrate (NO3−) while containing arsenic (in form of arsenite (As(III)) as a co-contaminant. The treatment was based on the combination of nitrate reduction to dinitrogen gas and arsenite oxidation to arsenate (exhibiting less toxicity, solubility, and mobility), which can be removed more easily in further post-treatment. We operated a bioelectrochemical reactor at continuous-flow mode with synthetic contaminated groundwater (33 mg N-NO3− L−1 and 5 mg As(III) L−1) identifying the key operational conditions. Different hydraulic retention times (HRT) were evaluated, reaching a maximum nitrate reduction rate of 519 g N-NO3− m3 Net Cathodic Compartment d−1 at HRT of 2.3 h with a cathodic coulombic efficiency of around 100 %. Simultaneously, arsenic oxidation was complete at all HRT tested down to 1.6 h reaching an oxidation rate of up to 90 g As(III) m−3Net Reactor Volume d -1. Electrochemical and microbiological characterization of single granules suggested that arsenite at 5 mg L−1 did not have an inhibitory effect on a denitrifying biocathode mainly represented by Sideroxydans sp. Although the coexistence of abiotic and biotic arsenic oxidation pathways was shown to be likely, microbial arsenite oxidation linked to denitrification by Achromobacter sp. was the most probable pathway. This research paves the ground towards a real application for treating groundwater with widespread pollutants
dc.description.sponsorship
This work was funded through the European Union’s Horizon
2020 project ELECTRA [no.826244]. S.P is a Serra Húnter Fellow (UdG-AG-575) and acknowledges the funding from the ICREA
Acadèmia award. LEQUiA [2017-SGR-1552] and Ecoaqua [2017SGR548] have been recognized as consolidated research groups by
the Catalan Government
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier
dc.relation.isformatof
Reproducció digital del document publicat a: https://doi.org/10.1016/j.watres.2020.116748
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Water Research, 2021, vol. 190, art.núm.116748
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Articles publicats (D-EQATA)
dc.rights
Attribution-NonCommercial-NoDerivatives 4.0 International
dc.rights.uri
dc.subject
dc.title
Electro-bioremediation of nitrate and arsenite polluted groundwater
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.relation.projectID
info:eu-repo/grantAgreement/EC/H2020/826244/EU/Electricity driven Low Energy and Chemical input Technology foR Accelerated bioremediation/ELECTRA
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
032439
dc.type.peerreviewed
peer-reviewed
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dc.relation.ProjectAcronym