N-removal in a granular sludge sequencing batch airlift reactor.
The removal of N-compounds in the sequencing batch airlift reactor (SBAR) containing granular sludge was studied under conditions of decreased dissolved oxygen (DO). A simulation model was developed to describe and evaluate the effects of several process conditions in the SBAR on N-removal performance. The model described the experimental data reasonable well. It has been shown that nitrification, denitrification, and removal of chemical oxygen demand (COD) can occur simultaneously in a granular sludge SBR. It has also been shown that the exact location of the autotrophic biomass influences the net N-removal. The distribution of the autotrophic biomass is influenced by the DO in the reactor. The optimal DO value is expected to be around 40% air saturation. It was shown that storage and subsequent degradation of poly-beta-hydroxybutyrate (PHB) benefit the denitrification. In particular, PHB is stored in bacteria situated in deeper layers of the granules below where the autotrophic activity occurs, serves as a C-source for denitrification.
Beun
J J
JJ
Kluyverlaboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
Heijnen
J J
JJ
van Loosdrecht
M C
MC
D000332:Aerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology
D012722:Sewage; D009584:Nitrogen; D010100:Oxygen