In:
Atmospheric Measurement Techniques, Copernicus GmbH, Vol. 12, No. 10 ( 2019-10-17), p. 5475-5501
Abstract:
Abstract. Smoke from laboratory chamber burning of peat fuels from Russia, Siberia, the
USA (Alaska and Florida), and Malaysia representing boreal, temperate,
subtropical, and tropical regions was sampled before and after passing
through a potential-aerosol-mass oxidation flow reactor (PAM-OFR) to
simulate intermediately aged (∼2 d) and well-aged
(∼7 d) source profiles. Species abundances in PM2.5 between aged and fresh profiles varied by several orders of magnitude with
two distinguishable clusters, centered around 0.1 % for reactive and ionic
species and centered around 10 % for carbon. Organic carbon (OC) accounted for 58 %–85 % of PM2.5 mass in fresh
profiles with low elemental carbon (EC) abundances (0.67 %–4.4 %). OC abundances decreased by
20 %–33 % for well-aged profiles, with reductions of 3 %–14 % for the
volatile OC fractions (e.g., OC1 and OC2, thermally evolved at 140 and 280 ∘C). Ratios of organic matter (OM) to OC abundances increased by
12 %–19 % from intermediately aged to well-aged smoke. Ratios of ammonia (NH3) to
PM2.5 decreased after intermediate aging. Well-aged NH4+ and NO3- abundances increased to 7 %–8 %
of PM2.5 mass, associated with decreases in NH3, low-temperature
OC, and levoglucosan abundances for Siberia, Alaska, and Everglades
(Florida) peats. Elevated levoglucosan was found for Russian peats,
accounting for 35 %–39 % and 20 %–25 % of PM2.5 mass for fresh and
aged profiles, respectively. The water-soluble organic carbon (WSOC)
fractions of PM2.5 were over 2-fold higher in fresh Russian peat (37.0±2.7 %) than in Malaysian (14.6±0.9 %) peat. While
Russian peat OC emissions were largely water-soluble, Malaysian peat
emissions were mostly water-insoluble, with WSOC ∕ OC ratios of 0.59–0.71 and
0.18–0.40, respectively. This study shows significant differences between fresh and aged peat
combustion profiles among the four biomes that can be used to establish
speciated emission inventories for atmospheric modeling and receptor model
source apportionment. A sufficient aging time (∼7 d) is
needed to allow gas-to-particle partitioning of semi-volatilized species,
gas-phase oxidation, and particle volatilization to achieve representative
source profiles for regional-scale source apportionment.
Type of Medium:
Online Resource
ISSN:
1867-8548
DOI:
10.5194/amt-12-5475-2019
DOI:
10.5194/amt-12-5475-2019-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2019
detail.hit.zdb_id:
2505596-3
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