Environmental Engineering Reference
In-Depth Information
Biomass combustion occurs at relatively low temperatures and is a significant
source of pyrogenic PAHs in nearshore subtidal sediments (Barra et al.
2007
; Gogou
et al.
2000
; Oanh et al.
1999
; Page et al.
1999
; Tobiszewski and Namiesnik
2012
).
However, aerosol from wheat and rice straw burning is enriched in HMW PAHs
(Ravindra et al.
2008
and references therein). Stark et al. (
2003
) identified three- to
six-ringed parent PAH compounds as the major PAHs in fireplace soots (see also
Figs. S18-S20, Supporting Material); alkylated three- and four-ringed compounds
were less abundant. Stark et al. (
2003
) noted that when soots have high total PAH
concentrations, they also contain larger amounts of three- and four-ringed parent
compounds. In contrast, soots with lower total PAH concentrations show a relative
increase in the amounts of five- and six-ringed PAHs.
Guillon et al. (
2013
) identified fluoranthene and pyrene as dominant parent PAH
compounds in particulates from wood combustion, whereas the dominant parent
HMW PAHs are benz[
a
]anthracene and chrysene, followed by benzo[
a
]pyrene.
Cyclopenta[
a
]phenanthrene, phenylnaphthalene and either cyclopenta[
cd
]pyrene or
benzo[
ghi
]luoranthene are present in fireplace soots (O'Malley et al.
1997
; Stark
et al.
2003
). Other HMW PAHs such as benzo[
ghi
]perylene are also produced by
biomass combustion (Dzepina et al.
2007
).
Under certain conditions (e.g., steady combustion and forest fires), and in con-
trast to HMW parent PAHs, alkylated naphthalenes, phenanthrenes, and even chry-
senes may be ubiquitous biomass combustion products (Figs. S18-S20, Supporting
Material; Wang and Fingas
2003
). Furthermore, three-ringed alkyl PAHs such as
1-methylphenanthrene, 1,7-dimethylphenanthrene (also known as pimanthrene)
and retene (1-methyl-7-isopropyl phenanthrene) are produced from abietic and
pimaric acid—both present in pine wood resin—and can be used as markers for
softwood combustion (Benner et al.
1995
; Bucheli et al.
2004
; Gogou et al.
2000
Sicre et al.
1987
; Yan et al.
2005
; Yunker et al.
2002
). The 2,6- dimethylphenanthrene
isomer is present at comparable concentrations in emissions from fossil fuel and
residential wood combustion (Benner et al.
1995
).
The PAHs derived from coal combustion are a concern in some regions of the
world (Chen et al.
2005
). Fluoranthene, pyrene, phenanthrene and anthracene domi-
nate in coal combustion profiles (Larsen and Baker
2003
and references therein).
Chrysene and benzo[
k
]luoranthene dominance has also been suggested as an indi-
cator of coal combustion (Ravindra et al.
2008
and references therein).
Dibenzothiophenes are also abundant in coal emission condensates (Marvin et al.
2000
; Sicre et al.
1987
) and industrial coal emissions, and escape from most modern
SO
x
removal processes (Lehndorff and Schwark
2009
).
Coal combustion patterns sometimes deviate from the general pyrogenic finger-
print of PAH homologues (i.e., maxima at the parent PAH), and can show maxima
for the methyl or dimethyl homologues of phenanthrene and anthracene (Oros and
Simoneit
2000
; Yunker et al.
2002
). Similarly, four-ringed methyl PAHs methylflu-
oranthene or methylpyrene may also show maxima in coal combustion PAH patterns
(Oros and Simoneit
2000
; Yunker et al.
2002
). PAH emissions from coal burning
depend not only on the coal rank, but also on the temperature of combustion.
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