Operating conditions analysis for a partial nitritation process with biomass retention.

MARTIN JAMILIS; FABRICIO GARELLI; HERNÁN DE BATTISTA; EVELINE VOLCKE

Florianópolis

Simposio; 12th IFAC Symposium on Dynamics and Control of Process Systems, including Biosystems (DYCOPS 2019); 2019

In wastewater treatment, ammonium removal is a key step which can be donebiologically. One method is by coupling a partial nitritation with the Anammox process. Thepartial nitritation goal is to convert half of the ammonium into nitrite, so ammonium andnitrite can be later converted into dinitrogen gas by Anammox bacteria. To obtain a stablepartial nitritation, ammonium oxidizing bacteria (AOB) have to prevail over nitrite oxidizingbacteria (NOB) so as to avoid further conversion of nitrite into nitrate. Two control objectivescan be identified for partial nitritation: the repression of NOB and the regulation of the effluentto obtain the required nitrite to ammonium ratio. In this work, the equilibrium points of thepartial nitrification process are analyzed to find operating conditions for AOB prevalence overNOB. Based on this analysis, a feeding strategy is proposed to regulate the effluent nitriteto ammonium ratio at the value required by Anammox. The study is based on the processdynamical model in a reactor with biomass retention.