Determination of size-segregated elements in diesel-biodiesel blend exhaust emissions

Rocha, Luiz Diego Silva; Corrêa, Sérgio Machado

doi:10.1007/s11356-018-1980-8

Cited by 21 publications

(6 citation statements)

References 24 publications

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“…The observation of mass concentrations increasing with decreasing carbon number for dicarboxylic acids (i.e., oxalate > succinate > adipate) is consistent with many past studies for other regions as larger chain acids undergo oxidative decay to eventually form oxalate (e.g., Kawamura and Ikushima, 1993;Kawamura and Sakaguchi, 1999;Sorooshian et al, 2007). Maleate is an unsaturated dicarboxylic acid emitted from gas and diesel engines (Rogge et al, 1993) and a product of the photooxidation of benzene (Kawamura and Ikushima, 1993). The aromatic dicarboxylic acid phthalate is a known photooxidation product of naphthalene and stems largely from plastic processing and fuel combustion (Fraser et al, 2003;Kautzman et al, 2010;Fu et al, 2012;Kleindienst et al, 2012).…”

Section: Water-soluble Ionssupporting

confidence: 89%

Size-resolved composition and morphology of particulate matter during the southwest monsoon in Metro Manila, Philippines

et al. 2019

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Abstract. This paper presents novel results from size-resolved particulate matter (PM) mass, composition, and morphology measurements conducted during the 2018 southwest monsoon (SWM) season in Metro Manila, Philippines. Micro-orifice uniform deposit impactors (MOUDIs) were used to collect PM sample sets composed of size-resolved measurements at the following aerodynamic cut-point diameters (Dp): 18, 10, 5.6, 3.2, 1.8, 1.0, 0.56, 0.32, 0.18, 0.10, and 0.056 µm. Each sample set was analyzed for composition of the water-soluble fraction. Analysis for mass was carried out on two sample sets, whereas black carbon (BC) and morphology analysis were analyzed on a single sample set. The bulk of the PM mass was between 0.18 and 1.0 µm with a dominant mode between 0.32 and 0.56 µm. Similarly, most of the black carbon (BC) mass was found between 0.10 and 1.0 µm, peaking between 0.18 and 0.32 µm. These peaks are located in the Greenfield gap, or the size range between 0.10 and 1.0 µm, where wet scavenging by rain is relatively inefficient. In the range between 0.10 and 0.18 µm, BC constituted 78.1 % of the measured mass. Comparable contributions of BC (26.9 %) and the water-soluble fraction (33.4 %) to total PM were observed and most of the unresolved mass, which amounted to 39.6 % in total, was for diameters exceeding 0.32 µm. The water-soluble ions and elements exhibited an average combined concentration of 8.53 µg m−3, with SO42-, NH4+, NO3-, Na+, and Cl− as the major contributors. Positive matrix factorization (PMF) was applied to identify the possible aerosol sources and estimate their contribution to the water-soluble fraction of collected PM. The factor with the highest contribution was attributed to “aged aerosol” (48.0 %), while “sea salt” (22.5 %) and “combustion” emissions (18.7 %) had comparable contributions. “Vehicular/resuspended dust” (5.6 %) and “waste processing” emissions (5.1 %) were also identified. Microscopy analysis highlighted the ubiquity of nonspherical particles regardless of size, which is significant when considering calculations of parameters such as single scattering albedo, the asymmetry parameter, and the extinction efficiency. The significant influence from aged aerosol to Metro Manila during the SWM season indicates that local sources in this megacity do not fully govern this coastal area's aerosol properties. The fact that the majority of the regional aerosol mass burden is accounted for by BC and other insoluble components has important downstream effects on the aerosol hygroscopic properties, which depend on composition. The results are relevant for understanding the impacts of monsoonal features on size-resolved aerosol properties, notably aqueous processing and wet scavenging. Finally, the results of this work provide contextual data for future sampling campaigns in Southeast Asia such as the airborne component of the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex) planned for the SWM season in 2019.

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Section: Water-soluble Ionssupporting

confidence: 89%

Size-resolved composition and morphology of particulate matter during the southwest monsoon in Metro Manila, Philippines

et al. 2019

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“…In contrast to a previous study that depicted haze-related urban PM as spherical based on 2D SEM (Zeb et al 2018 ), we have shown using 3D confocal imaging that DPM can contain particles with sharp appearing edges. Diesel emission particles can vary in size from fine particles less than 100nm to several micrometers (Liati et al 2013 , Rocha and Corrêa 2018 ); in view of the range of DPM size, it is possible that at least some particles imaged with confocal microscopy may consist of fine particle agglomeration. A recent study has reported that brake dust particles can also have jagged edges (Selley et al 2020 ).…”

Section: Discussionmentioning

confidence: 99%

Confocal microscopy 3D imaging of diesel particulate matter

Miyashita

Foley

Gill

et al. 2021

Environ Sci Pollut Res

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To date, diesel particulate matter (DPM) has been described as aggregates of spherule particles with a smooth appearing surface. We have used a new colour confocal microscope imaging method to study the 3D shape of diesel particulate matter (DPM); we observed that the particles can have sharp jagged appearing edges and consistent with these findings, 2D light microscopy demonstrated that DPM adheres to human lung epithelial cells. Importantly, the slide preparation and confocal microscopy method applied avoids possible alteration to the particles’ surfaces and enables colour 3D visualisation of the particles. From twenty-one PM10 particles, the mean (standard deviation) major axis length was 5.6 (2.25) μm with corresponding values for the minor axis length of 3.8 (1.25) μm. These new findings may help explain why air pollution particulate matter (PM) has the ability to infiltrate human airway cells, potentially leading to respiratory tract, cardiovascular and neurological disease.

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“…No signal was found for DJF, possibly due to the lower levels of precursors from reduced anthropogenic activity during this season. To demonstrate the importance of this process, M. T. Cruz et al (2019) attributed a significant fraction of the MOUDI aerosol mass in Metro Manila to an aged aerosol factor, consisting of multiple sources such as fuel combustion (Rocha & Corrêa, 2018), metallurgical processes (Youn et al, 2016), and biogenic emissions (Sorooshian et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

Characterizing Weekly Cycles of Particulate Matter in a Coastal Megacity: The Importance of a Seasonal, Size‐Resolved, and Chemically Speciated Analysis

et al. 2020

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We present the first study of the weekly cycles (WCs) of chemically speciated and size‐resolved particulate matter (PM) in Metro Manila, Philippines, a coastal megacity located within a highly complex meteorological environment that is subject to both anthropogenic and natural sources. To measure PM, Micro‐Orifice Uniform Deposit Impactors (MOUDIs) were deployed in Metro Manila from August 2018 to October 2019 and samples were analyzed for ionic and elemental species, including black carbon (BC). The WC in Metro Manila varied remarkably across seasons, linked to shifts in meteorology, transport, and aerosol source. Identified aerosol sources were traffic, local and regional burning, dust, sea salt, and secondary aerosol formation. Direct emissions induced a late workweek peak, while secondary aerosol formation led to a weekend peak in response to precursor buildup mainly from traffic. Seasonal analysis revealed that local burning from solid waste management and agricultural fires induced a strong WC peak while regional burning emissions from the Maritime Continent (MC) and possibly the Asian continent elevated seasonal baseline concentrations of the WC. BC showed a seasonally persistent WC, consistent in magnitude, weekly peak timing, and particle size. The dominant submicrometer WC and the contribution of BC across seasons have important ramifications on public health and policymaking, which are also discussed. As many of the observed WC patterns are undetectable when using only bulk PM, this study demonstrates that a seasonal, size‐resolved, and chemically speciated characterization is required to more fully understand the driving mechanisms governing WCs.

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Determination of size-segregated elements in diesel-biodiesel blend exhaust emissions

Cited by 21 publications

References 24 publications

Size-resolved composition and morphology of particulate matter during the southwest monsoon in Metro Manila, Philippines

Size-resolved composition and morphology of particulate matter during the southwest monsoon in Metro Manila, Philippines

Confocal microscopy 3D imaging of diesel particulate matter

Characterizing Weekly Cycles of Particulate Matter in a Coastal Megacity: The Importance of a Seasonal, Size‐Resolved, and Chemically Speciated Analysis

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