Biogas-based denitrification in a biotrickling filter: Influence of nitrate concentration and hydrogen sulfide.
The feasibility of NO3-removal by the synergistic action of a prevailing denitrifying anoxic methane oxidising (DAMO), and nitrate-reducing and sulfide-oxidising bacterial (NR-SOB) consortium, using CH4and H2S from biogas as electron donors in a biotrickling filter was investigated. The influence of NO3-concentration on N2O production during this process was also evaluated. The results showed that NO3-was removed at rates up to 2.8 g mreactor-3h-1using CH4as electron donor. N2O production rates correlated with NO3-concentration in the liquid phase, with a 10-fold increase in N2O production as NO3-concentration increased from 50 to 200 g m-3. The use of H2S as co-electron donor resulted in a 13-fold increase in NO3-removal rates (∼18 gNO3-m-3h-1) and complete denitrification under steady-state conditions, which was supported by higher abundances of narG, nirK, and nosZ denitrifying genes. Although the relative abundance of the DAMO population in the consortium was reduced from 60% to 13% after H2S addition, CH4removals were not compromised and H2S removal efficiencies of 100% were achieved. This study confirmed (i) the feasibility of co-oxidising CH4and H2S with denitrification, as well as (ii) the critical need to control NO3-concentration to minimize N2O production by anoxic denitrifiers. Biotechnol. Bioeng. 2017;114: 665-673. © 2016 Wiley Periodicals, Inc.
Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, Valladolid 47011, Spain.|Microbial Communities Laboratory, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland.
Juan C
JC
López
Microbial Communities Laboratory, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland.
Estefanía
E
Porca
Microbial Communities Laboratory, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland.
Gavin
G
Collins
Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, Valladolid 47011, Spain.
Rebeca
R
Pérez
Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, Valladolid 47011, Spain.
Alberto
A
Rodríguez-Alija
Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, Valladolid 47011, Spain.
Raúl
R
Muñoz
Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, Valladolid 47011, Spain.|Laboratory for Research on Advanced Processes for Wastewater Treatment - Engineering Institute, Juriquilla Academic Unit, National Autonomous University of Mexico (UNAM), Blvd. Juriquilla 3001, Querétaro 76230, Mexico.
Guillermo
G
Quijano
D001105:Archaea / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D056804:Biofuels; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D006862:Hydrogen Sulfide / Q000032:analysis / Q000378:metabolism*; D008697:Methane / Q000378:metabolism; D009566:Nitrates / Q000032:analysis / Q000378:metabolism*
D056804:Biofuels; D009566:Nitrates; D008697:Methane; D006862:Hydrogen Sulfide
anoxic hydrogen sulfide oxidation; biotrickling filter; denitrification; denitrifying anoxic methane oxidation; nitrate removal; nitrous oxide production