Stable isotope analyses of precipitation nitrogen sources in Guiyang, southwestern China.
Environ Pollut
; 230: 486-494, 2017 Nov.
Article
en En
| MEDLINE
| ID: mdl-28688925
ABSTRACT
To constrain sources of anthropogenic nitrogen (N) deposition is critical for effective reduction of reactive N emissions and better evaluation of N deposition effects. This study measured δ15N signatures of nitrate (NO3-), ammonium (NH4+) and total dissolved N (TDN) in precipitation at Guiyang, southwestern China and estimated contributions of dominant N sources using a Bayesian isotope mixing model. For NO3-, the contribution of non-fossil N oxides (NOx, mainly from biomass burning (24 ± 12%) and microbial N cycle (26 ± 5%)) equals that of fossil NOx, to which vehicle exhausts (31 ± 19%) contributed more than coal combustion (19 ± 9%). For NH4+, ammonia (NH3) from volatilization sources (mainly animal wastes (22 ± 12%) and fertilizers (22 ± 10%)) contributed less than NH3 from combustion sources (mainly biomass burning (17 ± 8%), vehicle exhausts (19 ± 11%) and coal combustions (19 ± 12%)). Dissolved organic N (DON) accounted for 41% in precipitation TDN deposition during the study period. Precipitation DON had higher δ15N values in cooler months (13.1) than in warmer months (-7.0), indicating the dominance of primary and secondary ON sources, respectively. These results newly underscored the importance of non-fossil NOx, fossil NH3 and organic N in precipitation N inputs of urban environments.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Monitoreo del Ambiente
/
Aire
/
Contaminantes Atmosféricos
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Nitrógeno
Tipo de estudio:
Prognostic_studies
País/Región como asunto:
Asia
Idioma:
En
Revista:
Environ Pollut
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2017
Tipo del documento:
Article