scholarly journals Characteristics and Sources of Black Carbon Aerosol in a Mega-City in the Western Yangtze River Delta, China

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 315
Author(s):  
Jun Li ◽  
Lei Jiang ◽  
Cheng Chen ◽  
Dantong Liu ◽  
Songshan Du ◽  
...  

A single particle soot photometer (SP2) was deployed in urban Nanjing, located in the Yangtze River Delta (China), to investigate the mixing state and sources of ambient refractory black carbon (rBC) from 26 January to 25 February 2014, along with an in-situ measurement of submicron aerosol chemical species by an aerodyne aerosol chemical speciation monitor (ACSM). The results showed that anthropogenic activities associated with firework emissions can be a significant source for rBC-containing particles during the period of the Chinese New Year, resulting from the evident peaks of rBC at midnight. During the residual periods, namely regular day (RD), the diurnal cycles of rBC presented two typical peaks that can be attributed to a synergistic influence of local traffic emissions and boundary layer changes throughout a day. Three coating factors, including organics, sulfate, and nitrate (-rich), were resolved using a positive matrix factorization (PMF) approach to explain the potential contribution of non-rBC coatings (i.e., organics, sulfate, and nitrate) to the coating thickness of rBC-containing particles. As the results show, organic aerosols (OAs) might be a major contributor to the coating thickness of rBC-coating particles during the whole period. The relative coating thickness (a ratio between coated particle size to BC core) exhibited a positive relationship with sulfate, indicative of the favorable coating factor during the episode caused by firework emissions. Source apportionment of rBC was performed via a multiple linear regression between the total rBC mass and each ACSM-PMF factor (rBC-ACSM-PMF). On average, biomass burning emissions accounted for 43%, being the largest contributor during the RD period, whereas local traffic emissions played a major role during the new year time.

2020 ◽  
Vol 96 ◽  
pp. 72-84 ◽  
Author(s):  
Yue Tan ◽  
Honglei Wang ◽  
Shuangshuang Shi ◽  
Lijuan Shen ◽  
Chen Zhang ◽  
...  

2014 ◽  
Vol 89 ◽  
pp. 415-424 ◽  
Author(s):  
B.L. Zhuang ◽  
T.J. Wang ◽  
J. Liu ◽  
S. Li ◽  
M. Xie ◽  
...  

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 789 ◽  
Author(s):  
Lian Duan ◽  
Lei Yan ◽  
Guangli Xiu

To comprehensively explore the transport of air pollutants, one-year continuous online observation of PM2.5 was conducted from 1 April 2015 to 31 March 2016 at Dianshan Lake, a suburban junction at the central of Yangtze River Delta. The chemical species of PM2.5 samples mainly focused on Organic carbon (OC), Elemental carbon (EC) and Water-Soluble Inorganic Ions (WSIIs). The annual average of PM2.5 concentration was 59.8 ± 31.7 µg·m−3, 1.7 times higher than the Chinese National Ambient Air Quality Standards (CNAAQS) (35 µg·m−3). SNA (SO42−, NO3− and NH4+) was the most dominated species of PM2.5 total WSIIs, accounting for 51% of PM2.5. PM2.5 and all of its chemical species shared the same seasonal variations with higher concentration in winter and spring, lower in autumn and summer. The higher NO3−/EC and NOR occurred in winter suggested that intensive secondary formation of nitrate contributed to the higher levels of PM2.5. Cluster analysis based on 72-h backward air trajectory showed that the air mass cluster from nearby inland cities, including Zhejiang, Anhui and Jiangxi Provinces contributed mostly to the total trajectories. Furtherly, potential source contribution function (PSCF) analysis revealed that local sources, namely the emissions in the Yangtze River, were the primary sources. During haze pollution, NO3− was the most important fraction of PM2.5 and the heterogeneous formation of nitrate became conspicuous. All the results suggested that the anthropogenic emissions (such as traffic exhaust) was responsible for the relatively high level of PM2.5 at this monitoring station.


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