A Novel Apportionment Method Utilizing Particle Mass Size Distribution across Multiple Particle Size Ranges

• Published in: Atmosphere Vol. 15; no. 8; p. 955
• Main Authors: Peizhi Wang, Qingsong Wang, Yuhuan Jia, Jingjin Ma, Chunying Wang, Liping Qiao, Qingyan Fu, Mellouki, Abdelwahid, Hui Chen, Li Li
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.08.2024
• Subjects: Aerosols; Air quality management; Algorithms; Atmospheric particulates; Cities; City centres; Comparative analysis; Decomposition; Environmental aspects; Identification and classification; Measurement; non-negative matrix factorization; optical particle counter; Outdoor air quality; Oxidation; Particle counters; Particle mass; particle mass size distribution; Particle size; Particle size distribution; Particles; Particulate matter; Pollutants; Pollution; Radiation counters; Secondary aerosols; Size distribution; source apportionment; Time series; Trace elements; China; United States > US
• ISSN: 2073-4433; 2073-4433
• DOI: 10.3390/atmos15080955

Many cities in China are facing the dual challenge of PM[sub.2.5] and PM[sub.10] pollution. There is an urgent need to develop a cost-effective method that can apportion both with high-time resolution. A novel and practical apportionment method is presented in this study. It combines the measurement of particle mass size distribution (PMSD) with an optical particle counter (OPC) and the algorithm of normalized non-negative matrix factorization (N-NMF). Applied in the city center of Baoding, Hebei, this method separates four distinct pollution factors. Their sizes (ordered from the smallest to largest) range from 0.16 μm to 0.6 μm, 0.16 μm to 1.0 μm, 0.5 μm to 17.0 μm, and 2.0 μm to 20.0 μm, respectively. They correspondingly contribute to PM[sub.2.5] (PM[sub.10] ) with portions of 26% (17%), 37% (26%), 33% (41%), and 4% (16%), respectively, on average. The smaller three factors are identified as combustion, secondary, and industrial aerosols because of their high correlation with carbonaceous aerosols, nitrate aerosols, and trace elements of Fe/Mn/Ca in PM[sub.2.5] , respectively. The largest-sized factor is linked to dust aerosols. The primary origin regions, oxidation degrees, and formation mechanisms of each source are further discussed. This provides a scientific basis for the comprehensive management of PM[sub.2.5] and PM[sub.10] pollution.