Physicochemical characterization and source apportionment of PM2.5 collected in Shanghai urban atmosphere and at Lin’an background atmospheric monitoring station
Abstract：The ambient PM2.5 particles were sampled synchronously at two sites,Xujiahui (a commercial center in Shanghai) and Lin’an background atmospheric monitoring station (in Zhejiang Province) in April 2008.The microscopic image of the particles were characterized by using of FESEM/EDS, while their chemical elements composition and the valence of zinc in the samples were investigated by using synchrotron radiation fluorescence technique. The average mass concentrations of PM2.5 in Xujiahui and Lin’an were (131.6?65.2), (83.5?22.9)μg/m3, respectively. The Xujiahui PM2.5 was primarily consisted by soots, flying ash and mineral particles, while the Lin’an PM2.5 was mainly composed by irregular shaped fine particles. Mass concentrations of the 19 elements (P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Pb) were almost higher in Xujiahui PM2.5 than in Lin’an PM2.5. The result of synchrotron radiation XANES indicated that the valence of zinc was mainly in the form of zinc sulfate at the both sites. Enrichment factor analysis demonstrated all the elements except K, Ca was more enriched in Shanghai PM2.5 than in Lin’an PM2.5.
