title: Model-based evaluation of mechanisms and benefits of mainstream shortcut nitrogen removal processes.
abstract: The main challenge in implementing shortcut nitrogen removal processes for mainstream wastewater treatment is the out-selection of nitrite oxidizing bacteria (NOB) to limit nitrate production. A model-based approach was utilized to simulate the impact of individual features of process control strategies to achieve NO(-)(2)-N shunt via NOB out-selection. Simulations were conducted using a two-step nitrogen removal model from the literature. Nitrogen shortcut removal processes from two case studies were modeled to illustrate the contribution of NOB out-selection mechanisms. The paper highlights a comparison between two control schemes; one was based on online measured ammonia and the other was based on a target ratio of 1 for ammonia vs. NOx (nitrate + nitrite) (AVN). Results indicated that the AVN controller possesses unique features to nitrify only that amount of nitrogen that can be denitrified, which promotes better management of incoming organics and bicarbonate for a more efficient NOB out-selection. Finally, the model was used in a scenario analysis, simulating hypothetical optimized performance of the pilot process. An estimated potential saving of 60% in carbon addition for nitrogen removal by implementing full-scale mainstream deammonification was predicted.
authors: Department of Mathematical Modelling, Statistics and Bio-informatics, Ghent University, Coupure Links 653, 9000 Ghent, Belgium E-mail: ahmed.al-omari@dcwater.com; DC Water and Sewer Authority, 20032 Washington, DC, USA.
authors: Ahmed
authors: A
authors: Al-Omari
authors: ARAconsult, Unterbergerstr.1, A-6020 Innsbruck, Austria.
authors: Bernhard
authors: B
authors: Wett
authors: Department of Mathematical Modelling, Statistics and Bio-informatics, Ghent University, Coupure Links 653, 9000 Ghent, Belgium E-mail: ahmed.al-omari@dcwater.com.
authors: Ingmar
authors: I
authors: Nopens
authors: Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA.
authors: Haydee
authors: H
authors: De Clippeleir
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Ghent, Belgium.
authors: Mofei
authors: M
authors: Han
authors: Civil and Environment Engineering Department, Old Dominion University, Norfolk, VA 23529, USA.
authors: Pusker
authors: P
authors: Regmi
authors: Hampton Roads Sanitation District, Virginia Beach, VA 23455, USA.
authors: Charles
authors: C
authors: Bott
authors: DC Water and Sewer Authority, 20032 Washington, DC, USA.
authors: Sudhir
authors: S
authors: Murthy
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D058440:Denitrification; D008962:Models, Theoretical; D009566:Nitrates / Q000378:metabolism; D058465:Nitrification; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D000641:Ammonia; D009566:Nitrates; D009573:Nitrites; D009584:Nitrogen; D062065:Wastewater; D014874:Water Pollutants, Chemical