Objectives To investigate the source characteristics and distribution of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate matters in Spring in Beijing.
Methods The air quality information published by the Beijing Municipal Environmental Protection Monitoring Center and air samples were collected by using atmospheric particulate matter sampler in a district of Beijing. The organic matters in PM2.5 were extracted by the Soxhlet extraction method, and the PAHs were quantitatively analyzed by gas chromatography-mass spectrometry. The molecular diagnostic ratio method was used to analyze the source of PAHs.
Results The daily mean value of AQI was positively correlated with anthracene, fluoranthene, benzoa anthracene, chrysene, benzob fluoranthene, and lndeno(1, 2, 3-cd)pyrene; and negatively correlated with acenaphthene and fluorene. Among them, the correlation coefficient with benzob fluoranthene was the highest, (r=0.772). With the deterioration of air quality, the concentrations of benzoa pyrene, Indeno (1, 2, 3-cd)pyrene, and Benzo(g, hi)perylene were increased and the difference was statistically significant (P < 0.01); in addition, the levels of lanthanum, cerium, phenanthrene, and anthracene were decreased, and the difference was statistically significant (P < 0.01). According to the characteristics and source analysis, in the cases of excellent and good air quality, the PAHs in particulate matters were mainly originated from the combustion of petroleum substances and liquid fossil fuels. In the cases of heavy pollution and severe pollution, the PAHs were mainly originated from the combustion of wood and coal, besides liquid fossil fuels.
Conclusions Polycyclic aromatic hydrocarbons in atmospheric particulate matters in spring of 2014 in Beijing were mainly originated from the combustion of coal and fossil fuels, which might be related to residential heating and traffic pollution.
DownLoad: