title: Citric acid application for denitrification process support in biofilm reactor.
abstract: The study demonstrated that citric acid, as an organic carbon source, can improve denitrification in Anaerobic Sequencing Batch Biofilm Reactor (AnSBBR). The consumption rate of the organic substrate and the denitrification rate were lower during the period of the reactor's acclimatization (cycles 1-60; 71.5 mgCOD L-1h-1and 17.81 mgN L-1h-1, respectively) than under the steady state conditions (cycles 61-180; 143.8 mgCOD L-1h-1and 24.38 mgN L-1h-1). The biomass yield coefficient reached 0.04 ± 0.02 mgTSS· mgCODre-1(0.22 ± 0.09 mgTSS mgNre-1). Observations revealed the diversified microbiological ecology of the denitrifying bacteria. Citric acid was used mainly by bacteria representing the Trichoccocus genus, which represented above 40% of the sample during the first phase of the process (cycles 1-60). In the second phase (cycles 61-180) the microorganisms the genera that consumed the acetate and formate, as the result of citric acid decomposition were Propionibacterium (5.74%), Agrobacterium (5.23%), Flavobacterium (1.32%), Sphaerotilus (1.35%), Erysipelothrix (1.08%).
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland. Electronic address: artur.mielcarek@uwm.edu.pl.
authors.forename: Artur
authors.initials: A
authors.lastname: Mielcarek
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 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, Warszawska St. 117a, Olsztyn 10-719, Poland. Electronic address: jawoj@uwm.edu.pl.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Janczukowicz
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environmental Biotechnology, Słoneczna St. 45g, Olsztyn 10-709, Poland. Electronic address: dorota.dabrowska@uwm.edu.pl.
authors.forename: Dorota
authors.initials: D
authors.lastname: Dabrowska
authors.affiliation: University of Warmia and Mazury in Olsztyn, Department of Environmental Biotechnology, Słoneczna St. 45g, Olsztyn 10-709, Poland. Electronic address: slavcm@uwm.edu.pl.
authors.forename: Slawomir
authors.initials: S
authors.lastname: Ciesielski
authors.affiliation: Atkins, Woodcote Grove, Ashley Road, Epsom KT18, United Kingdom. Electronic address: arthur.thornton@atkinsglobal.com.
authors.forename: Arthur
authors.initials: A
authors.lastname: Thornton
authors.affiliation: Bialystok University of Technology, Department of Technology in Engineering and Environmental Protection, Wiejska St. 45a, Białystok 15-351, Poland. Electronic address: j.struk@pb.edu.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Struk-Sokołowska
mesh_terms: D000085:Acetates / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D018407:Bacterial Physiological Phenomena / Q000187:drug effects; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D019343:Citric Acid / Q000494:pharmacology*; D058440:Denitrification / Q000187:drug effects*; D005561:Formates / Q000378:metabolism
chemical_list: D000085:Acetates; D005561:Formates; D019343:Citric Acid
keywords: Biofilm reactor; Citric acid; Denitrification; External carbon source; Metagenomic analyses