| Summary: | 碩士 === 國立成功大學 === 環境工程研究所 === 83 === In order to evalute the differences of characteristic
profiles of PAHs between industrial sources and traffic
sources , similar sampling schemes were conducted at vehicle
and motorcycle tunnels . The results show that the order of
the concentrations of total PAHs is motorcycle tunnel
(19870ng/m3) > industrial area(789ng/m3) > suburban area
(775ng/m3) > town area (676ng/m3).The greater concentrations
in the suburban area than those at the town area are due
to the large values of NaP concentration in the
suburban area.The fraction of particulate PAHs is
motorcycle tunnel(54%) > Vehicle tunnel(31%) > town
area(12%) > industrial area(10%) >suburban (8%). This is ,
More fraction is in particulate phase for PAHs emitted from
traffic sources . The histograms of size distributions measured
with MOUDI were converted tolog-normal distributions
with the Twomey algorithm . The results show that the size
distributions of individual PAHs are multi-modes: two modes
for dp < 1 μ m and one to three modes for dp > 1 μ m. Most
of the particulate PAHs at the motorcycle tunnel are with
diameter less than 1μm and the percentages are greater
than 90%. However , the results measured at other sites
show significant different patterns sampling sites. The mass
median aerodynamic diameters of each PAHs compounds are
vehicle tunnel (1.61 ± 1.07μm) >industrial area (1.19±
0.41μm) > suburban area (0.75 ±0.45μm) > motorcycle
tunnel(0.48 ± 0.33μm). Emission rates of total PAHs are
1.872mg/km for motorcycle. According to the ratio of
concentrations for VOCs in motorcycle tunnel and vehicle
tunnel, the emissions rates for vehicle are 1/10 to 1/100
times compared with motorcycle.
|
|---|
