title: Photo-oxygenation to support nitrification in an algal-bacterial consortium treating artificial wastewater.
abstract: Oxygenation by photosynthesis in a mixed culture of algae and nitrifiers was investigated for its potential to support nitrification. An open photo-bioreactor (1L fermentor; 30°C) was inoculated with an enriched culture of nitrifiers obtained from activated sludge and a pure culture of Scenedesmus sp. The reactor was illuminated (60 μmol/m2 s) and operated as a sequencing batch reactor with 50% discharge per cycle and sludge retention time of 15 or 30 days. Full nitrification of synthetic wastewater (50 mgNH4+-N/L) without mechanical aeration was achieved after less than 14 cycles (18.5 h React per 24h cycle) and the biomass steadily increased until a concentration of 1.9 g VSS/L with 29 mg chl-a/L. The maximum observed nitrification rate was 7.7 mgNH4+-N/Lh. A mass balance showed that ammonium removal was primarily by nitrification (81-85%) rather than by ammonium uptake by algae.
authors.affiliation: UNESCO-IHE Institute for Water Education, Department of Environmental Engineering and Water Technology, P.O. Box 3015, 2601 DA Delft, The Netherlands.
authors.forename: N G A I
authors.initials: NG
authors.lastname: Karya
authors.forename: N P
authors.initials: NP
authors.lastname: van der Steen
authors.forename: P N L
authors.initials: PN
authors.lastname: Lens
mesh_terms: D000641:Ammonia / Q000032:analysis; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental / Q000187:drug effects; D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D007700:Kinetics; D008027:Light; D058465:Nitrification / Q000187:drug effects*; D009584:Nitrogen / Q000032:analysis; D010100:Oxygen / Q000032:analysis / Q000494:pharmacology*; D058433:Photobioreactors / Q000382:microbiology; D010788:Photosynthesis / Q000187:drug effects*; D061005:Ponds / Q000382:microbiology; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D044444:Scenedesmus / Q000187:drug effects / Q000378:metabolism*; D062065:Wastewater / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D000641:Ammonia; D002734:Chlorophyll; D000077194:Chlorophyll A; D009584:Nitrogen; D010100:Oxygen; D000644:Quaternary Ammonium Compounds; D062065:Wastewater; D014874:Water Pollutants, Chemical