Physical Size Distribution Characterization of Diesel Particulate Matter and the Study of the Coagulation Process

1978 ◽  
Author(s):  
N. J. Khatri ◽  
John H. Johnson
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Diesel Particulate Matter ◽  
Diesel Particulate ◽  
Physical Size ◽  
Coagulation Process

Characterization and Quantification of Ultrafine Particles and Carbonaceous Components from Occupational Exposures to Diesel Particulate Matter in Selected Workplaces

2020 ◽  
Vol 64 (5) ◽  
pp. 490-502 ◽  
Author(s):  
Alan da Silveira Fleck ◽  
Cyril Catto ◽  
Gilles L’Espérance ◽  
Jean-Philippe Masse ◽  
Brigitte Roberge ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Ultrafine Particles ◽  
Occupational Exposures ◽  
Total Carbon ◽  
Geometric Standard Deviation ◽  
Diesel Particulate Matter ◽  
Subway Tunnel ◽  
Diesel Particulate ◽  
Exposure Levels

Abstract Questions still exist regarding which indicator better estimates worker’s exposure to diesel particulate matter (DPM) and, especially for ultrafine particles (UFP), how exposure levels and the characteristics of the particles vary in workplaces with different exposure conditions. This study aimed to quantify and characterize DPM exposures in three workplaces with different exposure levels: an underground mine, a subway tunnel, and a truck repair workshop. The same sampling strategy was used and included measurements of the particle number concentration (PNC), mass concentration, size distribution, transmission electron microscopy (TEM), and the characterization of carbonaceous fractions. The highest geometric means (GMs) of PNC and elemental carbon (EC) were measured in the mine [134 000 (geometric standard deviation, GSD = 1.5) particles cm−3 and 125 (GSD = 2.1) µg m−3], followed by the tunnel [32 800 (GSD = 1.7) particles cm−3 and 24.7 (GSD = 2.4) µg m−3], and the truck workshop [22 700 (GSD = 1.3) particles cm−3 and 2.7 (GSD = 2.4) µg m−3]. This gradient of exposure was also observed for total carbon (TC) and particulate matter. The TC/EC ratio was 1.4 in the mine, 2.5 in the tunnel and 8.7 in the workshop, indicating important organic carbon interference in the non-mining workplaces. EC and PNC were strongly correlated in the tunnel (r = 0.85; P < 0.01) and the workshop (r = 0.91; P < 0.001), but a moderate correlation was observed in the mine (r = 0.57; P < 0.05). Results from TEM showed individual carbon spheres between 10 and 56.5 nm organized in agglomerates, while results from the size distribution profiles showed bimodal distributions with a larger accumulation mode in the mine (93 nm) compared with the tunnel (39 nm) and the truck workshop (34 nm). In conclusion, the composition of the carbonaceous fraction varies according to the workplace, and can interfere with DPM estimation when TC is used as indicator. Also, the dominance of particles <100 nm in all workplaces, the high levels of PNC measured and the good correlation with EC suggest that UFP exposures should receive more attention on occupational routine measurements and regulations.

Effect of lubricant oil additive on size distribution, morphology, and nanostructure of diesel particulate matter

2014 ◽  
Vol 130 ◽  
pp. 33-40 ◽  
Author(s):  
Yuesen Wang ◽  
Xingyu Liang ◽  
Gequn Shu ◽  
Xiangxiang Wang ◽  
Xiuxiu Sun ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Diesel Particulate Matter ◽  
Diesel Particulate ◽  
Lubricant Oil

Chemical characterization of organic adsorbates on diesel particulate matter

1982 ◽  
Vol 54 (3) ◽  
pp. 354-357 ◽  
Author(s):  
James A. Yergey ◽  
Terence H. Risby ◽  
Samuel S. Lestz
Keyword(s):  
Particulate Matter ◽  
Chemical Characterization ◽  
Diesel Particulate Matter ◽  
Diesel Particulate ◽  
Organic Adsorbates

Effects of CVS Tunnel, Ambient and Instrument Dilution on Characteristics of Nano Diesel Particulate Matter Evolution

2012 ◽  
Author(s):  
Yuebin Wu ◽  
Nigel N. Clark ◽  
Daniel K. Carder
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Diesel Engine ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Diesel Particulate Matter ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Diesel Particulate ◽  
Exhaust Plume

In 2007, U.S. certification standards for heavy duty on-road diesel engine particulate matter (PM) emissions were reduced from 0.1g/bhp-hr to 0.01g/bhp-hr, representing an order of magnitude reduction in pollutant level. The Tier 4 standards for nonroad diesel engines, being phased in from 2008 through 2015, also require similar level of reduction in PM. Most conventional diesel engines could meet these low PM standards, once equipped with a diesel particulate filter (DPF). However, accurate, repeatable measurements of this PM may pose significant challenges. Gravimetric PM measurement involves diluting exhaust, then collecting the resultant aerosol sample on approved filter media. Few data exist to characterize the evolution of particulate matter (PM) in dilution tunnels, particularly at very low PM mass levels. Data are lacking as well, for PM evolution in portable dilution instruments and in exhaust plumes downstream of the tailpipe. Size distributions of ultra-fine particles in the diesel exhaust from a naturally aspirated ISUZU C240 diesel engine, equipped with a DPF, were studied. Particle size distribution data, during steady-state engine operations, were collected using a Cambustion DMS500 Fast Particulate Spectrometer. The effects of dilution ratios, dilution rates, and residence times on the diesel particulate matter (DPM) size distributions were analyzed and discussed. Measurements were made for three dilution methods: dilution in standard primary and secondary-dilution tunnels with a full scale Constant Volume Sampler (CVS) system, instrument dilution with a Portable Particulate Measurement Device (PPMD), and ambient dilution at the post-tailpipe exhaust plume centerline. Gaseous emissions measurements were utilized as surrogate confirmation of adequate mixing at the various measurement locations, as well as an indicator of dilution ratios. Tunnel sample results indicated varying size distributions at tunnel cross sections where the flow was still developing. Evolution of particle-size distributions was observed even for fully mixed primary flow conditions. Size distributions at the end of the secondary dilution tunnel were observed to vary with different secondary-dilution ratios. Particle-size distributions of post-tailpipe and PPMD test results were analyzed and compared with those results collected from the full-flow tunnel. Results from post-tailpipe sampling indicate that nucleation was the dominant process when the exhaust plume was diluted along the post-tailpipe centerline. Results from PPMD dilution measurements indicate that change of particle-size-distribution curves, including number count and mass concentration levels, were not as strongly correlated to dilution ratios as were the results from the other two sampling methods. This study shows that particle-size distributions measured inside full-flow dilution tunnel can adequately mimic freshly emitted exhaust sampled immediately post-tailpipe.

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