Trace Metals in Soot and PM2.5 from Heavy-Fuel-Oil Combustion in a Marine Engine.
Environ Sci Technol
; 52(11): 6714-6722, 2018 06 05.
Article
em En
| MEDLINE
| ID: mdl-29688717
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 VNi 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.
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Bases de dados:
MEDLINE
Assunto principal:
Óleos Combustíveis
/
Material Particulado
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2018
Tipo de documento:
Article
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