play a key role in the formation of cloud condensation nuclei (Kurtén et al. 2008;
Smith et al. 2008). In addition, studies have shown that the reaction of some
secondary organic aerosols with NH 3 or ammonium salts can produce absorbable
reduced nitrogen, which affects the optical properties of aerosols (Updyke et al.
2012). Heterocyclic compounds are mainly from the secondary reaction of pollutants
produced by anthropogenic sources (Smith et al. 2008).
On the other hand, oxidized organic nitrogen includes nitropolycyclic aromatic
hydrocarbons (N-PAHs) and nitrate compounds (nitrates, nitrate diesters, hydroxy
nitrates, peroxynitrates, peroxyacetyl nitrates (PANs), etc.) (Atkinson 1990). Oxidized organic nitrogen is mainly derived from the nitration of hydrocarbon precursors, such as biohydrocarbons and nitric acid. In summer, NO 3
À free radical
oxidation of isoprene, bismuth, or monoterpene produced from organic nitrogen is
an important source of secondary organic aerosols (Ng et al. 2008). At high
concentrations of NO x , photochemical oxidation of conjugated diene can produce
particulate nitrooxypolyols, so organic nitrogen participates in photochemical reactions in the atmosphere (Sato 2008).
6.3.3 Size Distribution of Aerosol Nr
Size distribution of nitrogen compounds plays an important role in their health,
environment, and climate effects and the physical and chemical atmospheric processes that affect aerosol properties during haze events (Chang et al. 2009; Contini
et al. 2014; Hu et al. 2014). In urban areas of China, NH 4
+ showed a single mode in
all four seasons, with the peaks mainly at the size of 0.43–1.1 μm (Tian et al. 2016).
NO 3
À exhibited a bimodal distribution, with two peaks located at the 0.43–1.1 μm
and 4.7–5.8 μm ranges, with the major part focused in the fine mode (Huang et al.
2016; Li et al. 2013; Tian et al. 2016; Zhao et al. 2011a).
Few studies reported the aerosol Nr size distributions in background areas in
China. Measurements at the Qira site show that (NH 4 ) 2 SO 4 and NH 4 NO 3 peaked at
0.65–1.1 μm and 3.3–7 μm during dusty weather conditions (Mikami et al. 2006).
Aerosol NO 3
À observed at Mt. Hua mainly arose from the photochemical oxidation
of NO x and exhibits a large peak at the size of 0.65–1.1 μm and a small peak at the
range of 4.7–5.8 μm (Li et al. 2011). The size distribution of NO 3
À is mainly
influenced by the thermodynamic equilibrium of HNO 3 +NH 3 !NH 4 NO 3 . The low
temperature in winter is beneficial for the formation of NH 4 NO 3 , so the size
distribution of NO 3
À in fine mode is coincident with that of NH 4
+ . However, the
coarse mode peak of NO 3
À may be caused by the adsorption of gaseous HNO 3 onto
coarse particles and reacted with alkaline species to form Ca(NO 3 ) 2 , Mg(NO 3 ) 2 ,
NaNO 3 , and KNO 3 .
The size distribution of amines was investigated by Liu et al. (2017a). In general,
amines were found to be predominant in the smallest size fraction (<0.49 μm). And
the concentrations of amines decreased stably with increasing particle size. The
amine concentration in the smallest and the largest size fraction generally differs by
120
Y. Pan et al.
Smith et al. 2008). In addition, studies have shown that the reaction of some
secondary organic aerosols with NH 3 or ammonium salts can produce absorbable
reduced nitrogen, which affects the optical properties of aerosols (Updyke et al.
2012). Heterocyclic compounds are mainly from the secondary reaction of pollutants
produced by anthropogenic sources (Smith et al. 2008).
On the other hand, oxidized organic nitrogen includes nitropolycyclic aromatic
hydrocarbons (N-PAHs) and nitrate compounds (nitrates, nitrate diesters, hydroxy
nitrates, peroxynitrates, peroxyacetyl nitrates (PANs), etc.) (Atkinson 1990). Oxidized organic nitrogen is mainly derived from the nitration of hydrocarbon precursors, such as biohydrocarbons and nitric acid. In summer, NO 3
À free radical
oxidation of isoprene, bismuth, or monoterpene produced from organic nitrogen is
an important source of secondary organic aerosols (Ng et al. 2008). At high
concentrations of NO x , photochemical oxidation of conjugated diene can produce
particulate nitrooxypolyols, so organic nitrogen participates in photochemical reactions in the atmosphere (Sato 2008).
6.3.3 Size Distribution of Aerosol Nr
Size distribution of nitrogen compounds plays an important role in their health,
environment, and climate effects and the physical and chemical atmospheric processes that affect aerosol properties during haze events (Chang et al. 2009; Contini
et al. 2014; Hu et al. 2014). In urban areas of China, NH 4
+ showed a single mode in
all four seasons, with the peaks mainly at the size of 0.43–1.1 μm (Tian et al. 2016).
NO 3
À exhibited a bimodal distribution, with two peaks located at the 0.43–1.1 μm
and 4.7–5.8 μm ranges, with the major part focused in the fine mode (Huang et al.
2016; Li et al. 2013; Tian et al. 2016; Zhao et al. 2011a).
Few studies reported the aerosol Nr size distributions in background areas in
China. Measurements at the Qira site show that (NH 4 ) 2 SO 4 and NH 4 NO 3 peaked at
0.65–1.1 μm and 3.3–7 μm during dusty weather conditions (Mikami et al. 2006).
Aerosol NO 3
À observed at Mt. Hua mainly arose from the photochemical oxidation
of NO x and exhibits a large peak at the size of 0.65–1.1 μm and a small peak at the
range of 4.7–5.8 μm (Li et al. 2011). The size distribution of NO 3
À is mainly
influenced by the thermodynamic equilibrium of HNO 3 +NH 3 !NH 4 NO 3 . The low
temperature in winter is beneficial for the formation of NH 4 NO 3 , so the size
distribution of NO 3
À in fine mode is coincident with that of NH 4
+ . However, the
coarse mode peak of NO 3
À may be caused by the adsorption of gaseous HNO 3 onto
coarse particles and reacted with alkaline species to form Ca(NO 3 ) 2 , Mg(NO 3 ) 2 ,
NaNO 3 , and KNO 3 .
The size distribution of amines was investigated by Liu et al. (2017a). In general,
amines were found to be predominant in the smallest size fraction (<0.49 μm). And
the concentrations of amines decreased stably with increasing particle size. The
amine concentration in the smallest and the largest size fraction generally differs by
120
Y. Pan et al.