title: Effect of the C:N:P ratio on the denitrifying dephosphatation in a sequencing batch biofilm reactor (SBBR).
abstract: A series of investigations were conducted using sequencing batch biofilm reactor (SBBR) to explore the influence of C:N:P ratio on biological dephosphatation including the denitrifying dephosphatation and the denitrification process. Biomass in the reactor occurred mainly in the form of a biofilm attached to completely submerged disks. Acetic acid was used as the source of organic carbon. C:N:P ratios have had a significant effect on the profiles of phosphate release and phosphate uptake and nitrogen removal. The highest rates of phosphate release and phosphate uptake were recorded at the C:N:P ratio of 140:70:7. The C:N ratio of 2.5:1 ensured complete denitrification. The highest rate of denitrification was achieved at the C:N:P ratio of 140:35:7. The increase of nitrogen load caused an increase in phosphates removal until a ratio C:N:P of 140:140:7. Bacteria of the biofilm exposed to alternate conditions of mixing and aeration exhibited enhanced intracellular accumulation of polyphosphates. Also, the structure of the biofilm encouraged anaerobic-aerobic as well as anoxic-anaerobic and absolutely anaerobic conditions in a SBBR. These heterogeneous conditions in the presence of nitrates may be a significant factor determining the promotion of denitrifying polyphosphate accumulating organism (DNPAO) development.
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, ul. Warszawska 117a, Olsztyn 10-719, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Mielcarek
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, ul. Warszawska 117a, Olsztyn 10-719, Poland. Electronic address: joanna.rodziewicz@uwm.edu.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Rodziewicz
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, ul. Warszawska 117a, Olsztyn 10-719, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Janczukowicz
authors.affiliation: Atkins, Woodcote Grove, Ashley Road, Epsom KT18, United Kingdom. Electronic address: artur.mielcarek@uwm.edu.pl.
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Thornton
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, ul. Warszawska 117a, Olsztyn 10-719, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Jóźwiak
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, ul. Warszawska 117a, Olsztyn 10-719, Poland.
authors.forename: Paula
authors.initials: P
authors.lastname: Szymczyk
mesh_terms: D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*
chemical_list: D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen
keywords: Denitrification and dephosphatation rates; Denitrifying dephosphatation; Enhanced intracellular polyphosphate accumulation; Nitrogen and phosphorus removal; Sequencing batch biofilm reactor; Wastewater treatment