Stable isotope analyses of precipitation nitrogen sources in Guiyang, southwestern China

Xue-Yan Liu; Hong-Wei Xiao; Hua-Yun Xiao; Wei Song; Xin-Chao Sun; Xu-Dong Zheng; Cong-Qiang Liu; Keisuke Koba

doi:10.1016/j.envpol.2017.06.010

Stable isotope analyses of precipitation nitrogen sources in Guiyang, southwestern China

Environ Pollut. 2017 Nov:230:486-494. doi: 10.1016/j.envpol.2017.06.010. Epub 2017 Jul 6.

Authors

Xue-Yan Liu¹, Hong-Wei Xiao², Hua-Yun Xiao³, Wei Song⁴, Xin-Chao Sun⁴, Xu-Dong Zheng⁴, Cong-Qiang Liu⁵, Keisuke Koba⁶

Affiliations

¹ Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China. Electronic address: liuxueyan@tju.edu.cn.
² Laboratory of Atmospheric Environment, Key Laboratory of Nuclear Resources and Environment (Ministry of Education), East China University of Technology, Nanchang 330013, China; School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang 330013, China.
³ State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China. Electronic address: xiaohuayun@vip.skleg.cn.
⁴ Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China.
⁵ Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
⁶ Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan; Center for Ecological Research, Kyoto University, Shiga, 520-2113, Japan.

PMID: 28688925
DOI: 10.1016/j.envpol.2017.06.010

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 (NO_x, mainly from biomass burning (24 ± 12%) and microbial N cycle (26 ± 5%)) equals that of fossil NO_x, 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 NO_x, fossil NH₃ and organic N in precipitation N inputs of urban environments.

Keywords: Ammonium; Dissolved organic nitrogen; Nitrate; Reactive nitrogen emission; SIAR; Stable isotope.

MeSH terms

Air / analysis*
Air / standards
Air Pollutants / analysis*
Bayes Theorem
China
Environmental Monitoring / methods*
Nitrogen / analysis*
Nitrogen Isotopes / analysis
Seasons
Urbanization

Substances

Air Pollutants
Nitrogen Isotopes
Nitrogen