title: A model for determination of operational conditions for successful shortcut nitrification.
abstract: Accumulation of nitrite in shortcut nitrification is influenced by several factors including dissolved oxygen concentration (DO), pH, temperature, free ammonia (FA), and free nitrous acid (FNA). In this study, a model based on minimum dissolved oxygen concentration (DOmin), minimum/maximum substrate concentration (Sminand Smax), was developed. The model evaluated the influence of pH (7-9), temperature (10-35 °C), and solids retention time (SRT) (5 days-infinity) on MSC values. The evaluation was conducted either by controlling total ammonium nitrogen (TAN) or total nitrite nitrogen (TNN), concentration at 50 mg N/L while allowing the other to vary from 0 to 1000 mg N/L. In addition, specific application for shortcut nitrification-anammox process at 10 °C was analyzed. At any given operational condition, the model was able to predict if shortcut nitrification can be achieved and provide the operational DO range which is higher than the DOminof AOB and lower than that of NOB. Furthermore, experimental data from different literature studies were taken for model simulation and the model prediction fit well the experiment. For the Sharon process, model prediction with default kinetics did not work but the model could make good prediction after adjusting the kinetic values based on the Sharon-specific kinetics reported in the literature. The model provides a method to identify feasible combinations of pH, DO, TAN, TNN, and SRT for successful shortcut nitrification.
authors.affiliation: Department of Civil and Environmental Engineering, University of Western Ontario, Spencer Engineering Building #3037, London, ON, N6A 5B9, Canada.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Chemical and Biochemical Engineering, University of Western Ontario, London, ON, N6A 5B9, Canada.
authors.forename: Mingu
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Civil and Environmental Engineering, University of Western Ontario, Spencer Engineering Building #3037, London, ON, N6A 5B9, Canada. gnakhla@uwo.ca.|Department of Chemical and Biochemical Engineering, University of Western Ontario, London, ON, N6A 5B9, Canada. gnakhla@uwo.ca.
authors.forename: George
authors.identifier: http://orcid.org/0000-0002-6807-129X
authors.initials: G
authors.lastname: Nakhla
mesh_terms: D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D058465:Nitrification; D009573:Nitrites / Q000032:analysis*
chemical_list: D009573:Nitrites
keywords: Ammonia oxidation bacteria (AOB); Minimum dissolved oxygen; Modeling prediction; Nitrite oxidation bacteria (NOB); Shortcut nitrification; Temperature; pH