Predicting N2O emissions from nitrifying and denitrifying biofilms : a modeling study
Wastewater treatment plants can be significant sources of nitrous oxide (N2O), a potent greenhouse gas. While our understanding of N2O emissions from suspended-growth processes has advanced significantly, less is known about emissions from biofilm processes. Biofilms may behave differently due to th...
| Publié dans: | Water science and technology : a journal of the International Association on Water Pollution Research. - 1986. - 75(2017), 3-4 vom: 17. Feb., Seite 530-538 |
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| Auteur principal: | |
| Autres auteurs: | , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2017
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| Accès à la collection: | Water science and technology : a journal of the International Association on Water Pollution Research |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Nitrites Waste Water Hydroxylamine 2FP81O2L9Z Nitrous Oxide K50XQU1029 Oxygen S88TT14065 |
| Résumé: | Wastewater treatment plants can be significant sources of nitrous oxide (N2O), a potent greenhouse gas. While our understanding of N2O emissions from suspended-growth processes has advanced significantly, less is known about emissions from biofilm processes. Biofilms may behave differently due to their substrate gradients and microbial stratification. In this study, we used mathematical modeling to explore the mechanisms of N2O emissions from nitrifying and denitrifying biofilms. Our ammonia-oxidizing bacteria biofilm model suggests that N2O emissions from biofilm can be significantly greater than from suspended-growth systems. The driving factor is the diffusion of hydroxylamine, a nitrification intermediate, from the aerobic to the anoxic regions of the biofilm. The presence of nitrite-oxidizing bacteria further increased emissions. For denitrifying biofilms, our results suggest that emissions are generally greater than for suspended-growth systems. However, the magnitude of the difference depends on the bulk dissolved oxygen, chemical oxygen demand, and nitrate concentrations, as well as the biofilm thickness. Overall, the accumulation and diffusion of key intermediates, i.e. hydroxylamine and nitrite, distinguish biofilms from suspended-growth systems. Our research suggests that the mechanisms of N2O emissions from biofilms are much more complex than suspended-growth systems, and that emissions may be higher in many cases |
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| Description: | Date Completed 26.06.2017 Date Revised 07.12.2022 published: Print Citation Status MEDLINE |
| ISSN: | 0273-1223 |
| DOI: | 10.2166/wst.2016.484 |