Kinetics of nitrification using a fluidized sand bed reactor with attached growth

Abstract

Abstract The oxidation of ammonium ion to nitrite and nitrate ion (nitrification) has been studied in a laboratory scale fluidized sand bed reactor with attached microbial growth. The undefined population of Nitrobacteracea organisms were immobilized on the sand particles by natural attachment after 2–3 months of adaptation. General balance equations have been formulated for a recycle reactor and oxygenation tank system. Kinetic experiments in the reactor and in a microrespirometer have been analyzed in terms of double Michaelis–Menten rate expression for the nitrogenous reactants and dissolved oxygen. Dynamic simulation of the batch integral reactor system was used to establish the error in the kinetic constant which arose due to assuming differential behavior. Design guidelines have been developed for the oxygen requirements in terms of oxygen transfer coefficients, oxygen enrichment, and liquid recycle rate.