 |
| Titel |
Characteristics of concentrations and chemical compositions for PM2.5 in the region of Beijing, Tianjin, and Hebei, China |
| VerfasserIn |
P. S. Zhao, F. Dong, D. He, X. J. Zhao, X. L. Zhang, W. Z. Zhang, Q. Yao, H. Y. Liu |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 9 ; Nr. 13, no. 9 (2013-05-06), S.4631-4644 |
| Datensatznummer |
250018631
|
| Publikation (Nr.) |
 copernicus.org/acp-13-4631-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| In order to study the temporal and spatial variations of PM2.5 and its
chemical compositions in the region of Beijing, Tianjin, and Hebei (BTH),
PM2.5 samples were collected at four urban sites in Beijing (BJ),
Tianjin (TJ), Shijiazhuang (SJZ), and Chengde (CD), and also one site at
Shangdianzi (SDZ) regional background station over four seasons from 2009 to
2010. The samples were weighted for mass concentrations and analyzed in the
laboratory for chemical profiles of 19 elements (Al, As, Ba, Ca, Cd, Co, Cr,
Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sr, Ti, V, and Zn), eight water-soluble
inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+,
Cl−, NO3−, and SO42−, and carbon fractions (OC and
EC). The concentrations of PM2.5 and its major chemical species were
season dependent and showed spatially similar characteristics in the plain
area of BTH. The average annual concentrations of PM2.5 were
71.8–191.2 μg m−3 at the five sites, with more than 90% of sampling days
exceeding 50 μg m−3 at BJ, TJ, and SJZ. PM2.5 pollution was most
serious at SJZ, and the annual concentrations of PM2.5, secondary
inorganic ions, OC, EC, and most crustal elements were all highest. Due
to stronger photochemical oxidation, the sum of concentrations of secondary
inorganic ions (NH4+, NO3−, and SO42− was
highest in the summer at SDZ, BJ, TJ, and CD. Analysis of electric charges
of water-soluble inorganic ions indicated the existence of nitric acid or
hydrochloric acid in PM2.5. For all five sites, the concentrations of
OC, EC and also secondary organic carbon (SOC) in the spring and summer were
lower than those in the autumn and winter. SOC had more percentages of
increase than primary organic carbon (POC) during the winter. The sums of
crustal elements (Al, Ca, Fe, Mg, Ti, Ba, and Sr) were higher in the spring
and autumn owing to more days with blowing or floating dust. The
concentrations of heavy metals were at higher levels in the BTH area by
comparison with other studies. In Shijiazhuang and Chengde, the PM2.5
pollution was dominated by coal combustion. Motor vehicle exhausts and coal
combustion emissions both played important roles in Tianjin PM2.5
pollution. However, motor vehicle exhausts had played a more important role in
Beijing owing to the reduction of coal consumption and sharp increase of
cars in recent years. At SDZ, regional transportation of air pollutants from
southern urban areas was significant. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|