Comparison of Two Mathematical Models for Greenhouse Gas Emission from Membrane Bioreactors

Abstract

Abstract. In this study two mathematical models (Model I and Model II), able to predict the nitrous oxide (N 2 O) and carbon dioxide (CO 2 ) emission from an University Cape Town (UCT) -membrane bioreactor (MBR) plant, have been compared. Model I considers the N 2 O production only during the denitrification. Model II takes into account the two ammonia-oxidizing bacteria (AOB) formation pathways for N 2 O. Both models were calibrated adopting real data. Results highlight that Model II had a better capability of reproducing the measured data especially in terms of N 2 O model outputs. Indeed, the average efficiency related to the N 2 O model outputs was equal to 0.3 and 0.38 for Model I and Model II respectively.