Source appointment of nitrogen in PM2.5 based on bulk δ15N signatures and a Bayesian isotope mixing model

SourcesN speciesδ¹⁵N/‰ReferencesCoal combustionNO₂+19.8 ± 5.2Felix et al. (2012)Coal combustionNH₃−8.9 ± 4.1Freyer (1991), Felix et al. (2013)Vehicle exhaustsNO₂−2.5 ± 1.5Walters et al. (2015)Vehicle exhaustsNH₃−3.4 ± 1.7Felix et al. (2013)Biomass burningNO₂+12.5 ± 3.1Hastings et al. (2009), Felix et al. (2012)Biomass burningNH₃+12.0Kawashima and Kurahashi (2011)Microbial N cycleNO₂−30.3 ± 9.4Li and Wang (2008), Felix et al. (2013), Felix and Elliott (2014)Animal wastesNH₃−19.0 ± 14.1Freyer (1978), Heaton (1987), Felix et al. (2013, 2014)Fertilizer applicationNH₃−26.8 ± 15.4Felix et al. (2013, 2014)

δ¹⁵N values of bulk N in PM_2.5 and dominant N sources assigned for PM_2.5 at the Beijing CRAES site (in red) and the Menyuan site (in blue). The box encompasses the 25th–75th percentiles, whiskers are SD values. The line and square in each box mark the median and arithmetic mean values, respectively. The number of jittered replicate δ¹⁵N data (dots around the boxes) is 1–34. Mean and SD values of source δ¹⁵N data were used in the SIAR model. δ¹⁵N values of N from dust were assumed as those of surface soils (Wang et al., 2014) according to the air mass backward trajectories (Fig. 2).

Table 2.

Mass concentrations of inorganic N ( ${NH}_{4}^{+}$ –N plus ${NO}_{3}^{-}$ –N), ${SO}_{4}^{2 -}$ –S, bulk N, molecular ratios of ${NH}_{4}^{+}$ to ${NO}_{3}^{-}$ , ${NH}_{4}^{+}$ to ${SO}_{4}^{2 -}$ , ${NH}_{4}^{+}$ to ( ${NO}_{3}^{-} + {SO}_{4}^{2 -}$ ) in PM_2.5 at Beijing (CRAES site) and a background site (Menyuan, Qinghai province) of China. Data of ambient NH₃ and SO₂ at Beijing site were cited from Carmichael et al. (2003), He et al. (2014), Wei et al. (2015). Data of NH₃ and SO₂ were cited from the background site of Waliguan in Qinghai Province (Carmichael et al., 2003).

Beijing (CRAES site)Menyuan, QinghaiPM_2.5 (μg/m³)264.3 ± 118.0 (43.0–433.6)13.0 ± 3.2 (7.0–17.8)

{NH}_{4}^{+}

-N (%)7.4 ± 3.4 (3.5–12.9)5.9 ± 1.8 (3.1–9.4)

{NO}_{3}^{-}

-N (%)5.0 ± 3.0 (0.7–9.4)1.9 ± 0.4 (1.2–2.6)

{SO}_{4}^{2 -}

-S (%)5.5 ± 2.4 (2.4–8.3)0.2 ± 0.0 (0.2–0.3)Inorganic N (%)12.4 ± 4.6 (5.1–22.2)7.8 ± 1.7 (5.7–11.3)Bulk N (%)16.7 ± 4.6 (8.2 –29.3)8.6 ± 5.6 (1.4–18.7)n-

{NH}_{4}^{+}

/n-

{NO}_{3}^{-}

2.5 ± 2.5 (0.5–9.0)3.3 ± 1.2 (1.2–4.9)n-

{NH}_{4}^{+}

/n-

{SO}_{4}^{2 -}

3.5 ± 1.6 (1.2–6.3)56.3 ± 14.3 (42.1–89.5)n-

{NH}_{4}^{+}

/(n-

{NO}_{3}^{-}

+ n-

{SO}_{4}^{2 -}

)1.1 ± 0.6 (0.4–2.9)3.1 ± 1.1 (1.2–4.7)n-

{NH}_{4}^{+}

/(n-

{NO}_{3}^{-}

+ 2*n-

{SO}_{4}^{2 -}

)0.8 ± 0.4 (0.3–1.7)2.9 ± 1.0 (1.1–4.5)NH₃ (μg/m³)14.14.8NO₂ (μg/m³)89.2 ± 21.2 (57.0–122.0)4.3 ± 1.3 (2.6–6.7)SO₂ (μg/m³)22.90.3n-NH₃/n-NO₂0.43.0n-NH₃/n-SO₂2.360.2n-NH₃/(n-NO₂ + n-SO₂)0.42.9n-NH₃/(n-NO₂ + 2*n-SO₂)0.32.7

Seventy-two-h air mass backward trajectories for all sampling dates at the Beijing CRAES site and the Menyuan site, based on NOAA HYSPLIT model back trajectories.

Correlations between δ¹⁵N values of PM_2.5 and molecular ratios of ${NH}_{4}^{+}$ to ( ${NO}_{3}^{-} + 2 * {SO}_{4}^{2 -}$ ) (expressed as n- ${NH}_{4}^{+}$ /n-( ${NO}_{3}^{-} + 2 * {NO}_{3}^{-} + 2 * {SO}_{4}^{2 -}$ )) in PM_2.5 at Beijing CRAES site and Menyuan site. The regression line was drawn on data of both sites.

Table 3.

Fractional contributions (F, %) of dominant N precursors and sources to bulk N in PM_2.5 at Beijing (CRAES site) and a background site (Menyuan, Qinghai province) of China. Values (mean ± SD; n = 10⁴) were calculated based on the output of the SIAR model.

Beijing (CRAES site)Menyuan, Qinghai

F_{{NH}_{3}}

40 ± 1064 ± 11

F_{{NO}_{2}}

41 ± 1122 ± 10

F_{{NH}_{3}} / F_{{NO}_{2}}

1.1 ± 6.34.4 ± 5.6F_fossil71 ± 12 F_non-fossil29 ± 12F_{coal combustion}39 ± 10 F_{vehicle exhausts}32 ± 12

F_{{NH}_{3} volatilization}

34 ± 12F_{biomass burning}46 ± 10

Fractional contributions of dominant N sources to bulk N in PM_2.5 at the Beijing CRAES site and the Menyuan site. Dots around the boxes (n = 10⁴) show the percentages estimated by the SIAR model. The box encompasses the 25th–75th percentiles, whiskers are the 5th and 95th percentiles. The line and cross in each box mark the median and arithmetic mean values, respectively.

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DOI: https://doi.org/10.1080/16000889.2017.1299672 | Journal eISSN: 1600-0889

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Language: English

Page range: 1299672 - 1299672

Submitted on: Jan 20, 2017

Accepted on: Feb 20, 2017

Published on: Jan 1, 2017

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

Keywords:

nitrogen isotope,

aerosol,

air pollution,

source apportionment,

ammonium

© 2017 Yan-Li Wang, Xue-Yan Liu, Wei Song, Wen Yang, Bin Han, Xiao-Yan Dou, Xu-Dong Zhao, Zhao-Liang Song, Cong-Qiang Liu, Zhi-Peng Bai, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 69 (2017): Issue 1

Source appointment of nitrogen in PM2.5 based on bulk δ15N signatures and a Bayesian isotope mixing model