title: Partial nitrification in MBBRs for mainstream deammonification with thin biofilms and alternating feed supply.
abstract: A new principle for mainstream nitrogen removal through nitritation followed by anammox was studied in a two-stage moving bed biofilm reactor (MBBR) configuration. The first stage was optimized for nitritation by using thin biofilms and a feed alternating between synthetic mainstream wastewater at 15°C and, for shorter periods, synthetic reject water at 30 °C. The exposure of the biofilm to reject water conditions aimed to improve the growth conditions for ammonia oxidizing bacteria, while inhibiting nitrite oxidizing bacteria. The biofilm thickness was maintained below 200 μm to ensure high exposure of the total biomass to the bulk reactor conditions. Nitritation was successfully achieved in the configuration, with a nitrite accumulation ratio above 75% during the majority of the study, and ammonia removal rates between 0.25 and 0.50 g NH4-N/L,d. The anoxic second stage, optimized for anammox, was fed with the effluent from the nitritation reactor, reaching nitrogen removal rates above 0.20 g TN/L,d.
authors.affiliation: AnoxKaldnes AB, Klosterängsvägen 11A, Lund SE-226 47, Sweden E-mail: maria.piculell@anoxkaldnes.com.
authors.forename: M
authors.initials: M
authors.lastname: Piculell
authors.affiliation: AnoxKaldnes AB, Klosterängsvägen 11A, Lund SE-226 47, Sweden E-mail: maria.piculell@anoxkaldnes.com.
authors.forename: M
authors.initials: M
authors.lastname: Christensson
authors.affiliation: Water and Environmental Engineering at the Department of Chemical Engineering, Lund University, PO Box 124, Lund SE-221 00, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Jönsson
authors.affiliation: AnoxKaldnes AB, Klosterängsvägen 11A, Lund SE-226 47, Sweden E-mail: maria.piculell@anoxkaldnes.com.
authors.forename: T
authors.initials: T
authors.lastname: Welander
mesh_terms: D000641:Ammonia / Q000737:chemistry / Q000378:metabolism*; D001419:Bacteria / Q000254:growth & development; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D058465:Nitrification; D009573:Nitrites / Q000737:chemistry / Q000378:metabolism*; D009584:Nitrogen / Q000032:analysis; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry
chemical_list: D000641:Ammonia; D009573:Nitrites; D009584:Nitrogen; D062065:Wastewater