Complete perchlorate reduction using methane as the sole electron donor and carbon source.
Environ Sci Technol
; 49(4): 2341-9, 2015 Feb 17.
Article
em En
| MEDLINE
| ID: mdl-25594559
ABSTRACT
Using a CH4-based membrane biofilm reactor (MBfR), we studied perchlorate (ClO4(-)) reduction by a biofilm performing anaerobic methane oxidation coupled to denitrification (ANMO-D). We focused on the effects of nitrate (NO3(-)) and nitrite (NO2(-)) surface loadings on ClO4(-) reduction and on the biofilm community's mechanism for ClO4(-) reduction. The ANMO-D biofilm reduced up to 5 mg/L of ClO4(-) to a nondetectable level using CH4 as the only electron donor and carbon source when CH4 delivery was not limiting; NO3(-) was completely reduced as well when its surface loading was ≤ 0.32 g N/m(2)-d. When CH4 delivery was limiting, NO3(-) inhibited ClO4(-) reduction by competing for the scarce electron donor. NO2(-) inhibited ClO4(-) reduction when its surface loading was ≥ 0.10 g N/m(2)-d, probably because of cellular toxicity. Although Archaea were present through all stages, Bacteria dominated the ClO4(-)-reducing ANMO-D biofilm, and gene copies of the particulate methane mono-oxygenase (pMMO) correlated to the increase of respiratory gene copies. These pieces of evidence support that ClO4(-) reduction by the MBfR biofilm involved chlorite (ClO2(-)) dismutation to generate the O2 needed as a cosubstrate for the mono-oxygenation of CH4.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Percloratos
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Reatores Biológicos
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Consórcios Microbianos
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Metano
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
China