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Simultaneous nitrification, denitrification, and phosphorus removal in a lab‐scale sequencing batch reactor
Author(s) -
Zeng Raymond J.,
Lemaire Romain,
Yuan Zhiguo,
Keller Jürg
Publication year - 2003
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.10744
Subject(s) - denitrifying bacteria , denitrification , sequencing batch reactor , enhanced biological phosphorus removal , nitrification , chemistry , anoxic waters , nitrite , phosphorus , nitrate , environmental chemistry , aerobic denitrification , anaerobic exercise , nitrous oxide , nitrogen , environmental engineering , wastewater , activated sludge , organic chemistry , environmental science , biology , physiology
Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic–anoxic‐enhanced biological phosphorus removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and phosphorus removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and phosphorus removal with a minimal requirement for COD. A lab‐scale sequencing batch reactor (SBR) was operated in alternating anaerobic–aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and phosphorus removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHAs), accompanied by phosphorus release. In the subsequent aerobic stage, PHA was oxidized and phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off‐gas analysis showed that the final denitrification product was mainly nitrous oxide (N 2 O), not N 2 . Further experimental results demonstrated that nitrogen removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen‐accumulating organisms (DGAOs), rather than denitrifying polyphosphate‐accumulating organisms (DPAOs), were responsible for the denitrification activity. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 170–178, 2003.