A mechanistic model was developed as an extension of the Activated Sludge Model No. 1 to describe three nitrous oxide (N2O) production pathways in a laboratory-scale anammox-enriched granular sequencing batch reactor. Heterotrophic denitrification and two processes mediated by ammonia oxidizing bacteria (AOB), that is, ammonia (NH4+) oxidation via hydroxylamine (NH2OH) and autotrophic denitrification, were considered. A systematic model calibration and validation protocol was developed to obtain a unique set of kinetic parameters in the extended model. The dynamic nitrate (NO3–), nitrite (NO2–), NH4+ and N2O behaviors were accurately predicted (R2 ≥ 0.81) under five different nitrogen loading conditions. The predicted N2O production factor ranged from 1.7 to 2.9%. The model-based analysis also revealed the dominant N2O production mechanisms in terms of the actual process conditions, that is, NH4+ oxidation via NH2OH when only NH4+ was supplied, heterotrophic denitrification when only NO2– was supplied, and a shift of the dominant mechanism when a mixture of NH4+ and NO2– was supplied.
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Additional information
- DOI
- Digital Object Identifier link open in new tab 10.1021/acs.est.7b05611
- Category
- Publikacja w czasopiśmie
- Type
- artykuł w czasopiśmie wyróżnionym w JCR
- Language
- angielski
- Publication year
- 2018