DAN Yangbin^1,2, HU Gongren¹, BIAN Yahui², CHEN Jinsheng², WANG Shanshan¹, YU Ruilian¹

(1. College of Chemical Engineering, Huaqiao University, Xiamen 361021, China;
2. Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China)

Abstract: The concentrations, chemical compositions and source contributions of PM2.5 at two representative sites in the coastal and urban areas of Zhangzhou City were studied based on the multi-site three-dimensional receptor model combined with the backward trajectory model. The results showed that the spatiotemporal distribution characteristics of atmospheric PM2.5 mass concentration in Zhangzhou were summer and autumn < winter and spring, offshore < urban area (coastal site: 37.3μg/m3 in summer and 52.1μg/m3 in winter; urban site: 38.5μg/m3 in summer and 86.2μg/m3 in winter). In general, the coastal site was mainly affected by the local air mass and the air mass from Jiangsu-Zhejiang Provinces, while the urban site was mainly affected by the air masses from Guangdong province and its offshore areas. The secondary inorganic components (SO42-, NO3-, and NH4+ ) in the PM2.5 at the coastal site were higher than those at the urban site, while the secondary organic pollution at the urban site were significantly higher than that at the coastal site in autumn. The concentrations of PM2.5 chemical components were higher at the coastal site than those at the urban site in winter due to the influence of the estuary terrain. There were seasonal differences in the source analysis results between the two sites. At the coastal site, secondary inorganic source in spring and winter and secondary organic source in summer and autumn were the largest. In the urban area, construction dust in spring, secondary organic source in summer, crustal dust in autumn and secondary inorganic source in winter contributed the most, respectively. At the coastal site, the largest contributors to PM2.5 from different air mass directions were secondary inorganic source from NNE in spring (20.5%), secondary organic source from SW in summer (14.3%), secondary organic source from NNE in autumn (10.0%) and secondary inorganic source from NE in winter (24.2%). For the urban site, the largest contributors to PM2.5 were construction dust from NNE in spring (18.0%), secondary organic source from WSW in summer (15.9%), crustal dust from NNE in autumn (15.4%) and secondary inorganic source from NNE in winter (24.3%).

Key words: Multi-site three-dimensional receptor model; Backward trajectory; PM2.5; chemical component; source contribution

EARTH AND ENVIRONMENT Vol.49, No.2, Tot No.340, 2021, Page 134-146