| Popis: |
This paper reports a field study of concentration and chemical characterization of PM2.5 emitted from a large egg production facility. PM2.5 samples were taken at five sampling locations covering emission source (in a layer barn) and four ambient stations at four wind directions surrounding the facility. Eight particulate matter (PM) sampling events were conducted from December 2008 to February 2009, through which 117 filter based PM samples were collected and analyzed for PM2.5 mass concentration, organic/elemental carbon (OC/EC), ionic species (nitrate, sulfate, ammonium, sodium, and potassium) and chemical elements (sodium through lead). PM2.5 concentrations in house were found in the range of 143.85 to 396.48 µg/m3, and four ambient stations were in range of 5.94-16.27 µg/m3 (station 2), 5.54-13.97 µg/m3 (station 3), 5.15-14.20 µg/m3 (station 4), and 4.05-16.71 µg/m3 (station 5) respectively. These winter data didn’t show spatially significant difference in ambient PM2.5 mass concentrations among different locations. Na and K concentrations in house PM2.5 samples were higher than that in ambient locations and they were highly correlated with each other. Aerosol NH4+ showed no difference in samples from house to ambient locations. Majority components in PM2.5 were organic compounds, and all PM2.5 samples had EC/TC ratio less than 0.1. PM2.5 samples in house had much higher concentrations of Ca, Cl, K, Mg, Na, P, S, Si and Zn than those of ambient PM2.5 samples. Both ambient and house stations had very low concentrations of Ag, Al, As, Ba, Cd, Ce, Co, Cr, Cs, Cu, In, Ni, Pb, Rb, Sb, Se, Sn, Sr, Ti, V, and Zr. |
