Photochemical emission and fixation of NOX gases in soils

Barrón, Vidal; Méndez, José M.; Balbuena, José; Cruz-Yusta, Manuel; Sánchez, Luis; Giménez, Carmen; Sacristán, Daniel; González-Guzmán, Adrián; Sánchez-Rodríguez, Antonio R.; Skiba, Ute M. ORCID: https://orcid.org/0000-0001-8659-6092; Inda, Alberto V.; Marques, José; Recio, José M.; Delgado, Antonio; del Campillo, María C.; Torrent, José. 2020 Photochemical emission and fixation of NOX gases in soils. Science of the Total Environment, 702, 134982. 9, pp. 10.1016/j.scitotenv.2019.134982

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Official URL: http://dx.doi.org/10.1016/j.scitotenv.2019.134982

Abstract/Summary

Gaseous nitrogen oxides (NOx), which result from the combustion of fossil fuels, volcanic eruptions, forest fires, and biological reactions in soils, not only affect air quality and the atmospheric concentration of ozone, but also contribute to global warming and acid rain. Soil NOx emissions have been largely ascribed to soil microbiological processes; but there is no proof of abiotic catalytic activity affecting soil NO emissions. We provide evidence of gas exchange in soils involving emissions of NOx by photochemical reactions, and their counterpart fixation through photocatalytic reactions under UV–visible irradiation. The catalytic activity promoting NOx capture as nitrate varied widely amongst different soil types, from low in quartzitic sandy soils to high in iron oxide and TiO2 rich soils. Clay soils with significant amounts of smectite also exhibited high rates of NOx sequestration and fixed amounts of N comparable to that of NO (nitric oxide) losses through biotic reactions. In these soils, a flux of 100 µg NNO m−2 h−1, as usually found in most ecosystems, could be reduced by these photochemical reactions by more than 60%. This mechanism of N fixation provides new insight into the nitrogen cycle and may inspire alternative strategies to reduce NO emissions from soils.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1016/j.scitotenv.2019.134982
UKCEH and CEH Sections/Science Areas:	Atmospheric Chemistry and Effects (Science Area 2017-)
ISSN:	0048-9697
Additional Keywords:	NOx, nitric oxide, nitrogen cycle, soil photocatalysis
NORA Subject Terms:	Agriculture and Soil Science
Date made live:	15 Nov 2019 15:12 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/525902

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.scitotenv.2019.134982

UKCEH and CEH Sections/Science Areas:

Atmospheric Chemistry and Effects (Science Area 2017-)

ISSN:

0048-9697

Additional Keywords:

NOx, nitric oxide, nitrogen cycle, soil photocatalysis

NORA Subject Terms:

Agriculture and Soil Science