AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Source Apportionment of Multiple Metals in PM2.5 in Beijing, China
MEI ZHENG, Xi Yang, Junyi Liu, Peking University
Abstract Number: 513 Working Group: Source Apportionment
Abstract Sources of multiple metals in PM2.5 including K, Ca, Fe, Zn, Pb, Ba, Mn, Cu, As, Se, Cr, and Ni were investigated in this study, which were measured for one year at 1-h resolution in Beijing by a Xact TM625 multi-metal monitor (from September 2016 to July 2017) at an urban site in Beijing. The levels of atmospheric metals in Beijing are lower than some other industrial cities in China, but two or three orders of magnitude higher than some cities in Europe and the U.S. They exhibited clear seasonal variations, with higher concentration in winter than summer. The comparison between haze and non-haze periods for metals was made to examine sources that contribute to the increase of fine particles during haze periods. In addition, positive matrix factorization (PMF) was applied for source apportionment of metals in PM2.5, and four factors including industry, vehicular exhaust, dust, and coal combustion were identified and quantified. The relative importance of different sources varied from metal to metal. The trajectory analysis indicated that the transport from the south of Beijing could contribute to some high level of metals during episodic events.