Full-scale emission results (N2O and CH4)

Abstract

Mathematical modelling of N2 O emissions is of great importance for the understanding and reduction of the environmental impact of wastewater treatment systems. This chapter reviews the current status of the modelling of N2 O emissions from wastewater treatment. The existing mathematical models describing all known microbial pathways for N2 O production are reviewed and discussed. These include N2 O production and consumption by heterotrophic denitrifiers, N2 O production by ammonia- oxidizing bacteria (AOB) through the hydroxylamine oxidation pathway and the AOB denitrification pathway and the integration of these pathways in single-pathway N2 O models. The two-pathway models are compared to single-pathway models. The calibration and validation of these models using lab-scale and full-scale experimental data is also reviewed. The mathematical modelling of N2 O production, while still being enhanced by new knowledge development, has reached a maturity that facilitates the estimation of site-specific N2 O emissions and the development of mitigation strategies for wastewater treatment plants taking into account the specific design and operational conditions of the plant.