Perchlorate reduction from a highly contaminated groundwater in the presence of sulfate-reducing bacteria in a hydrogen-fed biofilm.
Biotechnol Bioeng
; 110(12): 3139-47, 2013 Dec.
Article
en En
| MEDLINE
| ID: mdl-23797735
ABSTRACT
We used a hydrogen (H2 )-based biofilm to treat a groundwater contaminated with perchlorate (ClO(4)(-) ) at ~10 mg/L, an unusually high concentration. To enhance ClO(4)(-) removal, we either increased the H2 pressure or decreased the electron-acceptor surface loading. The ClO(4)(-) removal increased from 94% to 98% when the H2 pressure was increased from 1.3 to 1.7 atm when the total acceptor surface loading was 0.49 g H2 /m(2) day. We then decreased the acceptor surface loading stepwise from 0.49 to 0.07 g H2 /m(2) day, and the ClO(4)(-) removal improved to 99.6%, giving an effluent ClO(4)(-) concentration of 41 µg/L. However, the tradeoff was that sulfate (SO(4)(2-) ) reduction occurred, reaching 85% conversion at the lowest acceptor surface loading (0.07 g H(2) /m(2) day). In two steady states with the highest ClO(4)(-) reduction, we assayed for the presence of perchlorate-reducing bacteria (PRB), denitrifying bacteria (DB), and sulfate-reducing bacteria (SRB) by quantitative polymerase chain reaction (qPCR) targeting characteristic reductases. The qPCR results documented competition between PRB and SRB for space within the biofilm. A simple model analysis for a steady-state biofilm suggests that competition from SRB pushed the PRB to locations having a higher detachment rate, which prevented them from driving the ClO(4)(-) concentration below 41 µg/L.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Sulfatos
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Bacterias
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Contaminantes Químicos del Agua
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Agua Subterránea
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Percloratos
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Biopelículas
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Hidrógeno
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Biotechnol Bioeng
Año:
2013
Tipo del documento:
Article