@article {282,
	title = {Operating conditions analysis for a partial nitritation process with biomass retention.},
	journal = {IFAC-PapersOnLine},
	volume = {52},
	year = {2019},
	month = {07/2019},
	pages = {643 - 648},
	abstract = {<p>In wastewater treatment, ammonium removal is a key step which can be done biologically. One method is by coupling a partial nitritation with the Anammox process. The partial nitritation goal is to convert half of the ammonium into nitrite, so ammonium and nitrite can be later converted into dinitrogen gas by Anammox bacteria. To obtain a stable partial nitritation, ammonium oxidizing bacteria (AOB) have to prevail over nitrite oxidizing bacteria (NOB) so as to avoid further conversion of nitrite into nitrate. Two control objectives can be identified for partial nitritation: the repression of NOB and the regulation of the effluent to obtain the required nitrite to ammonium ratio. In this work, the equilibrium points of the partial nitrification process are analyzed to find operating conditions for AOB prevalence over NOB. Based on this analysis, a feeding strategy is proposed to regulate the effluent nitrite to ammonium ratio at the value required by Anammox. The study is based on the process dynamical model in a reactor with biomass retention.</p>
},
	keywords = {Control, Energy Biosystems, Environmental, Model-based Optimization},
	issn = {2405-8963},
	doi = {https://doi.org/10.1016/j.ifacol.2019.06.135},
	url = {http://www.sciencedirect.com/science/article/pii/S2405896319302228},
	author = {Mart{\'\i}n Jamilis and Fabricio Garelli and Hern{\'a}n De Battista and Eveline I.P. Volcke}
}
@article {255,
	title = {Stability and control of a partial nitritation reactor with biomass retention},
	journal = {Chemical Engineering Research and Design},
	volume = {144},
	year = {2019},
	month = {04/2019},
	pages = {318-333},
	abstract = {<p>Partial nitritation-anammox process is an interesting process option for biological nitrogen removal from wastewater. Partial nitritation needs to provide about equimolar ammonium and nitrite concentrations as required for the Anammox conversion. This study analyzes the equilibrium points of a stand-alone partial nitritation process as part of a two-reactor partial nitritation-anammox configuration. Conditions for the feasibility and stability of the equilibrium points are obtained in the general case of a reactor with biomass retention and controlled oxygen concentration. This knowledge is subsequently applied to achieve the desired reactor behavior, namely suppressing nitrite oxidizing bacteria (NOB) and obtaining the desired effluent nitrite:ammonium ratio. The optimal oxygen concentration to achieve these two objectives is determined. Moreover, a control algorithm is proposed to drive the process to the desired operating point. Its steady state behavior is assessed for changing influent ammonium concentrations and biomass retention times. The dynamic performance of the controller is tested through simulation as well, prioritizing NOB suppression in case the two objectives are not compatible.</p>
},
	keywords = {Anammox, Bacteria Competition, Control, Equilibrium Points, Partial nitritation},
	issn = {0263-8762},
	doi = {https://doi.org/10.1016/j.cherd.2019.02.017},
	url = {http://www.sciencedirect.com/science/article/pii/S0263876219300644},
	author = {Mart{\'\i}n Jamilis and Fabricio Garelli and Hern{\'a}n De Battista and Eveline I.P. Volcke}
}
