Trace Metals in Soot and PM<inf>2.5</inf>from Heavy-Fuel-Oil Combustion in a Marine Engine

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Date
2018-06-05Type
- Journal Article
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Cited 76 times in
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Abstract
Heavy fuel oil (HFO) particulate matter (PM) emitted by marine engines is known to contain toxic heavy metals, including vanadium (V) and nickel (Ni). The toxicity of such metals will depend on the their chemical state, size distribution, and mixing state. Using online soot-particle aerosol mass spectrometry (SP-AMS), we quantified the mass of five metals (V, Ni, Fe, Na, and Ba) in HFO-PM soot particles produced by a marine diesel research engine. The in-soot metal concentrations were compared to in-PM2.5 measurements by inductively coupled plasma-optical emission spectroscopy (ICP-OES). We found that <3% of total PM2.5 metals was associated with soot particles, which may still be sufficient to influence in-cylinder soot burnout rates. Since these metals were most likely present as oxides, whereas studies on lower-temperature boilers report a predominance of sulfates, this result implies that the toxicity of HFO PM depends on its combustion conditions. Finally, we observed a 4-to-25-fold enhancement in the ratio V:Ni in soot particles versus PM2.5, indicating an enrichment of V in soot due to its lower nucleation/condensation temperature. As this enrichment mechanism is not dependent on soot formation, V is expected to be generally enriched within smaller HFO-PM particles from marine engines, enhancing its toxicity. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000271717Publication status
publishedExternal links
Journal / series
Environmental Science & TechnologyVolume
Pages / Article No.
Publisher
American Chemical SocietyOrganisational unit
03690 - Lohmann, Ulrike / Lohmann, Ulrike
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Citations
Cited 76 times in
Web of Science
Cited 80 times in
Scopus
ETH Bibliography
yes
Altmetrics