Source apportionment of PM2.5 pollution in an industrial city in southern China
2017
Zou, Bei-Bing | Huang, Xiao Feng | Dai, Jing | Zhang, Bin | Zeng, Li-Wu | Feng, Ning | He, Ling-Yan
Severe PM2.5 pollution has become a great challenge to atmospheric pollution control in China. Most of previous aerosol source apportionment studies in China focused only on part of PM2.5 (e.g., organic matter in composition or PM1 in size) or lacked source contributions identified with necessary tempo-spatial variations, which makes the results not convincible enough for policy making. In this study, five various sites were selected for simultaneous PM2.5 observation in an industrial city in the Pearl River Delta (PRD) of South China during all four seasons of 2014. A positive matrix factorization (PMF) model was applied to the datasets of measured chemical species to perform source apportionment with the results as: (1) The annual mean PM2.5 concentration was 52.6 μg/m³, with secondary sulfate, vehicle emissions, secondary organic aerosol (SOA), and secondary nitrate identified as the major sources, contributing 24.6%, 14.5%, 12.0%, and 10.9% to PM2.5, respectively. Ship emissions, fugitive dust, biomass combustion, industrial emissions, and aged sea salt each contributed 3%–8%. (2) The tempo-spatial variations of sources reveal that secondary sulfate, SOA, biomass combustion, and ship emissions had obvious regional pollution characteristics; however, vehicle emissions, secondary nitrate, fugitive dust, and industrial emissions showed obvious local emission characteristics. (3) The exceeding standard polluted days (PM2.5>75 μg/m³) appeared with secondary nitrate, biomass burning, and SOA increasing mostly in concentration, which should be controlled more strictly. This study highlights the importance of SOA in PM2.5 pollution in China, which has been scarcely quantified for bulk PM2.5 in the literature.
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