title: N2O emissions: modeling the effect of process configuration and diurnal loading patterns.
abstract: The objective of this research was to develop a mechanistic model for quantifying N2O emissions from activated sludge plants and demonstrate how this may be used to evaluate the effects of process configuration and diurnal loading patterns. The model describes the mechanistic link between the factors recognized to correlate positively with N2O emissions. The primary factors are the presence of ammonia and nitrite accumulation. Low dissolved oxygen concentrations also may be implicated through differential impacts on ammonia-oxidizing bacteria (AOB) versus nitrite-oxidizing bacteria (NOB) activity. Factors promoting N2O emissions at treatment plants are discussed below. The model was applied to data from laboratory and pilot-scale systems. From a practical standpoint, plant configuration (e.g., plug-flow versus complete-mix), influent loading patterns (and peak load), and certain operating strategies (e.g., handling of return streams) are all important in determining N2O emissions.
authors.affiliation: EnviroSim Associates Ltd., Hamilton, Ontario, Canada. dwight@envirosim.com
authors.forename: Dwight
authors.initials: D
authors.lastname: Houweling
authors.forename: Pascal
authors.initials: P
authors.lastname: Wunderlin
authors.forename: Peter
authors.initials: P
authors.lastname: Dold
authors.forename: Chris
authors.initials: C
authors.lastname: Bye
authors.forename: Adriano
authors.initials: A
authors.lastname: Joss
authors.forename: Hansruedi
authors.initials: H
authors.lastname: Siegrist
mesh_terms: D002138:Calibration; D002940:Circadian Rhythm; D008962:Models, Theoretical; D009609:Nitrous Oxide / Q000032:analysis*; D010865:Pilot Projects; D012722:Sewage; D012995:Solubility
chemical_list: D012722:Sewage; D009609:Nitrous Oxide