|
|
|
| Characteristics and sources of metal elements in PM2.5 during hazy days in Nanjing |
|
|
|
|
Abstract Fine particular matter (PM2.5) was continuously sampled with a TEOM-1400a (tapered element oscillating microbalance)ambient particulate monitor (Rupprecht and Patashnick Corp.) in Nanjing from 13 June 2007 to 29 May 2008. Thirty metal elements, including K, Al, Ca and Pb etc., were determined using an inductive coupled plasma-mass spectrometry(ICP-MS), and characteristics of these components were analyzed and compared between hazy and non-hazy days. The annual mean concentration of PM2.5 in Nanjing was around 103μg/m3, quite higher than that in clean cities, and that the PM2.5 concentration in hazy days was 1.35 fold higher than that in non-hazy days. It was also found that the concentration of metal elements in hazy days was higher than that in non-hazy days in autumn and winter, but there was no significant difference between hazy and non-hazy days in spring. Enrichment factor (EF) analysis for metal elements showed that metal components from anthropogenic origins (Cu, Se, Hg and Bi) were highly enriched in PM2.5,especially in hazy days. A source analysis further revealed that PM2.5 in hazy days in Nanjing mainly originated from soil dusts, metallurgic emissions, the combustion of fossil fuel, refuse incineration and emissions from construction industries, which contributed 29.21%, 20.15%, 27.15%, 7.09% and 5.10%, respectively, to the total mass of PM2.5.
|
|
Received: 05 June 2009
|
|
|
|
|
|
|
