title: Characterization and source apportionment of size-segregated atmospheric particulate matter collected at ground level and from the urban canopy in Tianjin.
abstract: To investigate the size distributions of chemical compositions and sources of particulate matter (PM) at ground level and from the urban canopy, a study was conducted on a 255 m meteorological tower in Tianjin from December 2013 to January 2014. Thirteen sets of 8 size-segregated particles were collected with cascade impactor at 10 m and 220 m. Twelve components of particles, including water-soluble inorganic ions and carbonaceous species, were analyzed and used to apportion the sources of PM with positive matrix factorization. Our results indicated that the concentrations, size distributions of chemical compositions and sources of PM at the urban canopy were affected by regional transport due to a stable layer approximately 200 m and higher wind speed at 220 m. The concentrations of PM, Cl-and elemental carbon (EC) in fine particles at 10 m were higher than that at 220 m, while the reverse was true for NO3-and SO42-. The concentrations of Na+, Ca2+, Mg2+, Cl-and EC in coarse particles at 10 m were higher than that at 220 m. The size distributions of major primary species, such as Cl-, Na+, Ca2+, Mg2+and EC, were similar at two different heights, indicating that there were common and dominant sources. The peaks of SO42-, NH4+, NO3-and organic carbon (OC), which were partly secondary generated species, shifted slightly to the smaller particles at 220 m, indicating that there was a different formation mechanism. Industrial pollution and coal combustion, re-suspended dust and marine salt, traffic emissions and transport, and secondary inorganic aerosols were the major sources of PM at both heights. With the increase in vertical height, the influence of traffic emissions, re-suspended dust and biomass burning on PM weakened, but the characteristics of regional transport from Hebei Province and Beijing gradually become obvious.
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Bao-Shuang
authors.initials: BS
authors.lastname: Liu
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: envwujh@nankai.edu.cn.
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Wu
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Peng
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Zhang
authors.affiliation: Tianjin Institute of Meteorological Science, Tianjin 300074, China.
authors.forename: Su-Qin
authors.initials: SQ
authors.lastname: Han
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Yin-Chang
authors.initials: YC
authors.lastname: Feng
authors.affiliation: State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Tan
authors.initials: T
authors.lastname: Zhu
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry*; D001272:Atmosphere / Q000032:analysis* / Q000737:chemistry*; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D007221:Industry; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter
keywords: Chemical composition; Particulate matter; Size distribution; Source apportion; Urban canopy