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The role of coupled DNRA-Anammox during nitrate removal in a highly saline lake
- Source :
- Science of the Total Environment, Science of the Total Environment, Elsevier, 2022, 806, pp.150726. ⟨10.1016/j.scitotenv.2021.150726⟩, Science of the Total Environment, 2022, 806, pp.150726. ⟨10.1016/j.scitotenv.2021.150726⟩
- Publication Year :
- 2022
-
Abstract
- Nitrate (NO3-) removal from aquatic ecosystems involves several microbially mediated processes, including denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and anaerobic ammonium oxidation (anammox), controlled by slight changes in environmental gradients. In addition, some of these processes (i.e. denitrification) may involve the production of undesirable compounds such as nitrous oxide (N2O), an important greenhouse gas. Saline lakes are prone to the accumulation of anthropogenic contaminants, making them highly vulnerable environments to NO3- pollution. The aim of this paper was to investigate the effect of light and oxygen on the different NO3- removal pathways under highly saline conditions. For this purpose, mesocosm experiments were performed using lacustrine, undisturbed, organic-rich sediments from the Petrola Lake (Spain), a highly saline waterbody subject to anthropogenic NO3- pollution. The revised 15N-isotope pairing technique (15N-IPT) was used to determine NO3- sink processes. Our results demonstrate for the first time the coexistence of denitrification, DNRA, and anammox processes in a highly saline lake, and how their contribution was determined by environmental conditions (oxygen and light). DNRA, and especially denitrification to N2O, were the dominant nitrogen (N) removal pathways when oxygen and/or light were present (up to 82%). In contrast, anoxia and darkness promoted NO3- reduction by DNRA (52%), combined with N loss by anammox (28%). Our results highlight the role of coupled DNRA-anammox, which has not yet been investigated in lacustrine sediments. We conclude that anoxia and darkness favored DNRA and anammox processes over denitrification and therefore to restrict N2O emissions to the atmosphere.
- Subjects :
- 0106 biological sciences
Pollution
inorganic chemicals
Environmental Engineering
Denitrification
010504 meteorology & atmospheric sciences
Nitrogen
media_common.quotation_subject
Nitrous Oxide
chemistry.chemical_element
01 natural sciences
Mesocosm
chemistry.chemical_compound
Nitrate
Ammonium Compounds
Environmental Chemistry
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Waste Management and Disposal
Ecosystem
ComputingMilieux_MISCELLANEOUS
0105 earth and related environmental sciences
media_common
Nitrates
Chemistry
010604 marine biology & hydrobiology
Aquatic ecosystem
Nitrous oxide
6. Clean water
Lakes
13. Climate action
Anammox
Environmental chemistry
[SDE]Environmental Sciences
Oxidation-Reduction
Subjects
Details
- ISSN :
- 00489697 and 18791026
- Database :
- OpenAIRE
- Journal :
- Science of the Total Environment, Science of the Total Environment, Elsevier, 2022, 806, pp.150726. ⟨10.1016/j.scitotenv.2021.150726⟩, Science of the Total Environment, 2022, 806, pp.150726. ⟨10.1016/j.scitotenv.2021.150726⟩
- Accession number :
- edsair.doi.dedup.....f32cea5afcac7d83f80b752c629d8c57