A high-resolution regional emission inventory of atmospheric mercury and its comparison with multi-scale inventories: a case study of Jiangsu, China
A better understanding of the discrepancies in multi-scale inventories could give an insight into their approaches and limitations as well as provide indications for further improvements; international, national, and plant-by-plant data are primarily obtained to compile those inventories. In thi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/15119/2016/acp-16-15119-2016.pdf |
| Summary: | A better understanding of the discrepancies in multi-scale inventories could
give an insight into their approaches and limitations as well as provide
indications for further improvements; international, national, and
plant-by-plant data are primarily obtained to compile those inventories. In
this study we develop a high-resolution inventory of Hg emissions at
0.05° × 0.05° for Jiangsu, China, using a bottom-up
approach and then compare the results with available global/national
inventories. With detailed information on individual sources and the updated
emission factors from field measurements applied, the annual Hg emissions of
anthropogenic origin in Jiangsu in 2010 are estimated at 39 105 kg, of
which 51, 47, and 2 % were Hg<sup>0</sup>, Hg<sup>2+</sup>, and Hg<sup>p</sup>, respectively. This
provincial inventory is thoroughly compared to three downscaled national
inventories (NJU, THU, and BNU) and two global ones (AMAP/UNEP and
EDGARv4.tox2). Attributed to varied methods and data sources, clear
information gaps exist in multi-scale inventories, leading to differences in
the emission levels, speciation, and spatial distributions of atmospheric Hg.
The total emissions in the provincial inventory are 28, 7, 19, 22, and
70 % larger than NJU, THU, BNU, AMAP/UNEP, and EDGARv4.tox2,
respectively. For major sectors, including power generation, cement, iron and
steel, and other coal combustion, the Hg contents (HgC) in coals/raw
materials, abatement rates of air pollution control devices (APCDs) and
activity levels are identified as the crucial parameters responsible for the
differences in estimated emissions between inventories. Regarding speciated
emissions, a larger fraction of Hg<sup>2+</sup> is found in the provincial
inventory than national and global inventories, resulting mainly from the
results by the most recent domestic studies in which enhanced Hg<sup>2+</sup> were
measured for cement and iron and steel plants. Inconsistent information on
large power and industrial plants is the main source of differences in
spatial distribution of emissions between the provincial and other
inventories, particularly in southern and northwestern Jiangsu, where
intensive coal combustion and industry are located. Quantified with Monte
Carlo simulation, uncertainties in the provincial inventory are smaller than
those of the NJU national inventory, resulting mainly from the more accurate
activity data of individual plants and the reduced uncertainties in HgC in
coals/raw materials. |
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| ISSN: | 1680-7316 1680-7324 |