Premium
Containment of Biogenic Sulfide Production in Continuous Up‐Flow Packed‐Bed Bioreactors with Nitrate or Nitrite
Author(s) -
Hubert Casey,
Nemati Mehdi,
Jenneman Gary,
Voordouw Gerrit
Publication year - 2003
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp020128f
Subject(s) - nitrate , nitrite , chemistry , sulfate , bioreactor , environmental chemistry , sulfate reducing bacteria , sulfide , packed bed , nitrification , electron donor , inorganic chemistry , chromatography , nitrogen , biochemistry , organic chemistry , catalysis
Produced water from the Coleville oil field in Saskatchewan, Canada was used to inoculate continuous up‐flow packed‐bed bioreactors. When 7.8 mM sulfate and 25 mM lactate were present in the in‐flowing medium, H 2 S production (souring) by sulfate‐reducing bacteria (SRB) was prevented by addition of 17.5 mM nitrate or 20 mM nitrite. Changing the sulfate or lactate concentration of the in‐flowing medium indicated that the concentrations of nitrate or nitrite required for containment of souring decreased proportionally with a lowered concentration of the electron donor lactate, while the sulfate concentration of the medium had no effect. Microbial communities were dominated by SRB. Nitrate addition did not give rise to changes in community composition, indicating that lactate oxidation and H 2 S removal were caused by the combined action of SRB and nitrate‐reducing, sulfide‐oxidizing bacteria (NR‐SOB). Apparently the nitrite concentrations formed by these NR‐SOB did not inhibit the SRB sufficiently to cause community shifts. In contrast, significant community shifts were observed upon direct addition of high concentrations (20 mM) of nitrite. Strains NO3A and NO2B, two newly isolated, nitrate‐reducing bacteria (NRB) emerged as major community members. These were found to belong to the ϵ‐division of the Proteobacteria, to be most closely related to Campylobacter lari , and to oxidize lactate with nitrate or nitrite as the electron acceptor. Thus the mechanism of microbial H 2 S removal in up‐flow packed‐bed bioreactors depended on whether nitrate (SRB/NR‐SOB) or nitrite (SRB/NR‐SOB as well as NRB) was used. However, the amount of nitrate or nitrite needed to completely remove H 2 S was dictated by the electron donor (lactate) concentration, irrespective of mechanism.