Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of particulate matter from wood- and dung-fueled cooking fires, garbage and crop residue burning, brick kilns, and other sources
The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) characterized widespread and under-sampled combustion sources common to South Asia, including brick kilns, garbage burning, diesel and gasoline generators, diesel groundwater pumps, idling motorcycles, traditional and modern coo...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/2259/2018/acp-18-2259-2018.pdf |
| Summary: | The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE)
characterized widespread and under-sampled combustion sources common to South
Asia, including brick kilns, garbage burning, diesel and gasoline generators,
diesel groundwater pumps, idling motorcycles, traditional and modern cooking
stoves and fires, crop residue burning, and heating fire. Fuel-based
emission factors (EFs; with units of pollutant mass emitted per kilogram of fuel
combusted) were determined for fine particulate matter (PM<sub>2.5</sub>), organic
carbon (OC), elemental carbon (EC), inorganic ions, trace metals, and organic
species. For the forced-draft zigzag brick kiln, EF<sub>PM<sub>2.5</sub></sub>
ranged from 12 to 19 g kg<sup>−1</sup> with major contributions from OC (7 %),
sulfate expected to be in the form of sulfuric acid (31.9 %), and other
chemicals not measured (e.g., particle-bound water). For the clamp kiln,
EF<sub>PM<sub>2.5</sub></sub> ranged from 8 to 13 g kg<sup>−1</sup>, with major contributions
from OC (63.2 %), sulfate (23.4 %), and ammonium (16 %). Our
brick kiln EF<sub>PM<sub>2.5</sub></sub> values may exceed those previously
reported, partly because we sampled emissions at ambient temperature after
emission from the stack or kiln allowing some particle-phase OC and sulfate
to form from gaseous precursors. The combustion of mixed household garbage
under dry conditions had an EF<sub>PM<sub>2.5</sub></sub> of
7.4 ± 1.2 g kg<sup>−1</sup>, whereas damp conditions generated the highest
EF<sub>PM<sub>2.5</sub></sub> of all combustion sources in this study, reaching up
to 125 ± 23 g kg<sup>−1</sup>. Garbage burning emissions contained
triphenylbenzene and relatively high concentrations of heavy metals (Cu, Pb,
Sb), making these useful markers of this source. A variety of cooking stoves
and fires fueled with dung, hardwood, twigs, and/or other biofuels were
studied. The use of dung for cooking and heating produced higher
EF<sub>PM<sub>2.5</sub></sub> than other biofuel sources and consistently emitted
more PM<sub>2.5</sub> and OC than burning hardwood and/or twigs; this trend was
consistent across traditional mud stoves, chimney stoves, and three-stone cooking
fires. The comparisons of different cooking stoves and cooking fires revealed
the highest PM emissions from three-stone cooking fires (7.6–73 g kg<sup>−1</sup>),
followed by traditional mud stoves (5.3–19.7 g kg<sup>−1</sup>), mud stoves with
a chimney for exhaust (3.0–6.8 g kg<sup>−1</sup>), rocket stoves
(1.5–7.2 g kg<sup>−1</sup>), induced-draft stoves (1.2–5.7 g kg<sup>−1</sup>),
and the bhuse chulo stove (3.2 g kg<sup>−1</sup>), while biogas had no detectable
PM emissions. Idling motorcycle emissions were evaluated before and after
routine servicing at a local shop, which decreased EF<sub>PM<sub>2.5</sub></sub>
from 8.8 ± 1.3 to 0.71 ± 0.45 g kg<sup>−1</sup> when averaged across
five motorcycles. Organic species analysis indicated that this reduction in
PM<sub>2.5</sub> was largely due to a decrease in emission of motor oil, probably
from the crankcase. The EF and chemical emissions profiles developed in this
study may be used for source apportionment and to update regional emission
inventories. |
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| ISSN: | 1680-7316 1680-7324 |