title: Long-term starvation and subsequent reactivation of a high-rate partial nitrification activated sludge pilot plant.
abstract: The starvation process of a high-rate partial nitrification system during 30 days and its controlled recovery were studied in an activated sludge pilot plant. Four ammonium-starved reactors under anoxic, aerobic and two different alternating aerobic/anoxic conditions were evaluated. The highest and the lowest decay rates of ammonia oxidizing bacteria (AOB) were obtained under full aerobic (0.24 d(-1)) and full anoxic (0.11 d(-1)) conditions, respectively. The evolution of biomass activity correlated well with the AOB quantification using FISH technique. AOB fractions lower than 1% were measured in the four reactors after 23 days of starvation. The recovery of the system was achieved in only 5 days using a nitrogen loading rate (NLR) control loop, obtaining the same conditions than before the long-term starvation period with a NLR of 1.2 g N L(-1)d(-1) and 98% of nitrite accumulation in the effluent.
authors: Department of Chemical Engineering, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain.
authors: Josep A
authors: JA
authors: Torà
authors: Javier
authors: J
authors: Lafuente
authors: Juan A
authors: JA
authors: Baeza
authors: Julián
authors: J
authors: Carrera
mesh_terms: D000332:Aerobiosis; D000641:Ammonia / Q000378:metabolism; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D017404:In Situ Hybridization, Fluorescence; D007700:Kinetics; D009566:Nitrates / Q000032:analysis; D058465:Nitrification / Q000502:physiology*; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D010865:Pilot Projects; D012722:Sewage / Q000382:microbiology*; D012995:Solubility; D013997:Time Factors
chemical_list: D009566:Nitrates; D009573:Nitrites; D012722:Sewage; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen