Post-anoxic denitrification driven by PHA and glycogen within enhanced biological phosphorus removal.
The objective of this research was to interrogate and develop a better understanding for a process to achieve post-anoxic denitrification without exogenous carbon augmentation within enhanced biological phosphorus removal (EBPR). Sequencing batch reactors fed real wastewater and seeded with mixed microbial consortia were operated under variable anaerobic-aerobic-anoxic and organic carbon loading conditions. The process consistently achieved phosphorus and nitrogen removal, while the observed specific denitrification rates were markedly higher than expected for post-anoxic systems operated without exogenous organic carbon addition. Investigations revealed that post-anoxic denitrification was predominantly driven by glycogen, an intracellular carbon storage polymer associated with EBPR; moreover, glycogen reserves can be significantly depleted post-anoxically without compromising EBPR. Success of the proposed process is predicated on providing sufficient organic acids in the influent wastewater, such that residual nitrate carried over from the post-anoxic period is reduced and polyhydroxyalkanoate (PHA) synthesis occurs.
Department of Civil Engineering, University of Idaho, PO Box 441022, Moscow, ID 83844-1022, USA. ecoats@uidaho.edu
Erik R
ER
Coats
Alexander
A
Mockos
Frank J
FJ
Loge
D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000032:analysis; D058440:Denitrification; D005232:Fatty Acids, Volatile / Q000032:analysis; D006003:Glycogen / Q000378:metabolism*; D007700:Kinetics; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000302:isolation & purification*; D054813:Polyhydroxyalkanoates / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000379:methods*
D005232:Fatty Acids, Volatile; D009566:Nitrates; D054813:Polyhydroxyalkanoates; D010758:Phosphorus; D002244:Carbon; D006003:Glycogen; D009584:Nitrogen