Pollution Characteristics and Source Apportionment of Fine Particulate Matter in Autumn and Winter in Puyang, China

Abstract

As one of the air pollution transmission channels around the beijing-Tianjin-Hebei region, Puyang frequently suffer from severe airpollution in autumn and winter. In order to study the characteristics and main sources of fine particulate matter during these periods, manual membrane sampling of PM2.5 was conducted at three national control sites from October 15, 2017, to January 13, 2018. Chemical composition analysis was conducted and, combined with a PMF receptor model, source analysis of the fine particles was also undertaken. The results show that the average mass concentration of PM2.5 in Puyang was 94.16 μg·m-3 in the autumn and winter of 2017, and Pushuihe station was the most polluted site. During the heating season, the three control stations all recorded the frequent occurrence of severe and serious pollution events, while the frequency of mild pollution events decreased. When heavy pollution events occurred, the concentrations of NO2 and CO increased significantly. The main components of PM2.5 were water-soluble ions (52.33%), OCEC (25.32%), and crustal elements (0.08%). The concentrations of NO3- were high while the concentrations of SO42- were low. When heavy pollution occurred, the concentrations of water-soluble ions, OC, EC, and K in PM2.5 increased significantly, while the concentrations of crustal elements decreased. During the sampling period, the conversion ratios of sulfur and nitrogen in Puyang were high and atmospheric oxidation was strong. The transformation of sulfur and nitrogen promoted the occurrence of heavy pollution. Emissions of NOx, CO, and VOCs were higher in Puyang in 2017, and the source apportionment results showed that the main sources of PM2.5 in autumn and winter were secondary inorganic salts (37%), industrial sources (16%), secondary organic aerosol (SOA, 14%), biomass combustion (12%), mobile sources (9%), coal burning (7%), and dust (4%). Secondary transformation played an important role in the development of heavy pollution events in Puyang. It is necessary to focus on the control of emissions from industrial sources, biomass combustion, moving source, and civil coal combustion.