δ 15 N-stable isotope analysis of NH x : An overview on analytical measurements, source sampling and its source apportionment.

Autor: Bhattarai N; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084 China.; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084 China., Wang S; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084 China.; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084 China., Pan Y; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 China., Xu Q; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084 China.; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084 China., Zhang Y; Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science & Technology, Nanjing, 210044 China., Chang Y; Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science & Technology, Nanjing, 210044 China., Fang Y; CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016 China.
Jazyk: angličtina
Zdroj: Frontiers of environmental science & engineering [Front Environ Sci Eng] 2021; Vol. 15 (6), pp. 126. Date of Electronic Publication: 2021 Mar 15.
DOI: 10.1007/s11783-021-1414-6
Abstrakt: Agricultural sources and non-agricultural emissions contribute to gaseous ammonia (NH 3 ) that plays a vital role in severe haze formation. Qualitative and quantitative contributions of these sources to ambient PM 2.5 (particulate matter with an aerodynamic equivalent diameter below 2.5 µm) concentrations remains uncertain. Stable nitrogen isotopic composition (δ 15 N) of NH 3 and NH 4 + (δ 15 N(NH 3 ) and δ 15 N(NH 4 + ), respectively) can yield valuable information about its sources and associated processes. This review provides an overview of the recent progress in analytical techniques for δ 15 N(NH 3 ) and δ 15 N(NH 4 + ) measurement, sampling of atmospheric NH 3 and NH 4 + in the ambient air and their sources signature (e.g., agricultural vs. fossil fuel), and isotope-based source apportionment of NH 3 in urban atmosphere. This study highlights that collecting sample that are fully representative of emission sources remains a challenge in fingerprinting δ 15 N(NH 3 ) values of NH 3 emission sources. Furthermore, isotopic fractionation during NH 3 gas-to-particle conversion under varying ambient field conditions (e.g., relative humidity, particle pH, temperature) remains unclear, which indicates more field and laboratory studies to validate theoretically predicted isotopic fractionation are required. Thus, this study concludes that lack of refined δ 15 N(NH 3 ) fingerprints and full understanding of isotopic fractionation during aerosol formation in a laboratory and field conditions is a limitation for isotope-based source apportionment of NH 3 . More experimental work (in chamber studies) and theoretical estimations in combinations of field verification are necessary in characterizing isotopic fractionation under various environmental and atmospheric neutralization conditions, which would help to better interpret isotopic data and our understanding on NH x (NH 3 + NH 4 + ) dynamics in the atmosphere.
Electronic Supplementary Material: Supplementary material is available in the online version of this article at 10.1007/s11783-021-1414-6 and is accessible for authorized users. Supplementary material includes supplementary tables on summary of recent isotope-based source apportionment studies on ambient NH 3 derived from δ 15 N(NH 3 ) values (Table A1); and summary of recent isotope-based source apportionment studies on particulate NH 4 + derived from δ 15 N(NH 4 + ) values (Table A2).
(© Higher Education Press 2021.)
Databáze: MEDLINE
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