scholarly journals Measurement Report: Interpretation of Wide Range Particulate Matter Size Distributions in Delhi

2021 ◽  
Author(s):  
Ülkü Alver Şahin ◽  
Roy M. Harrison ◽  
Mohammed S. Alam ◽  
David C. S. Beddows ◽  
Dimitrios Bousiotis ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Particle Number ◽  
Size Fraction ◽  
Distribution Data ◽  
Size Distributions ◽  
Post Monsoon ◽  
Wide Range ◽  
Autumn And Winter ◽  
The City ◽  
Very High

Abstract. Delhi is one of the world’s most polluted cities, with very high concentrations of airborne particulate matter. However, little is known on the factors controlling the characteristics of particle number size distributions. Here, new measurements are reported from three field campaigns conducted in winter, pre-monsoon and post-monsoon seasons on the Indian Insitute of Technology campus in the south of the city. Particle number size distributions were measured simultaneously using a Scanning Mobility Particle Sizer and a Grimm optical particle monitor, covering 15 nm to > 10 µm diameter. The merged, wide-range size distributions were categorised into five size ranges: nucleation (15–20 nm), Aitken (20–100 nm), accumulation (100 nm–1 µm), large fine (1–2.5 µm) and coarse (2.5–10 µm) particles. The ultrafine fraction (15–100 nm) accounts for about 52 % of all particles by number (PN10), but just 1 % by PM10 volume (PV10). The measured size distributions are markedly coarser than most from other parts of the world, but are consistent with earlier cascade impactor data from Delhi. Our results suggest substantial aerosol processing by coagulation, condensation and water uptake in the heavily polluted atmosphere, which takes place mostly at nighttime and in the morning hours. Total number concentrations are highest in winter, but the mode of the distribution is largest in the post-monsoon (autumn) season. The accumulation mode particles dominate the particle volume in autumn and winter, while the coarse mode dominates in summer. Polar plots show a huge variation between both size fractions in the same season and between seasons for the same size fraction. The diurnal pattern of particle numbers is strongly reflective of a road traffic influence upon concentrations, especially in autumn and winter. There is a clear influence of diesel traffic at nighttime when it is permitted to enter the city, and also indications in the size distribution data of a mode < 15 nm, probably attributable to CNG/LPG vehicles. New particle formation appears to be infrequent, and in this dataset is limited to one day in the summer campaign. Our results reveal that the very high emissions of airborne particles in Delhi, particularly from traffic, determine the variation of particle number size distributions.

scholarly journals Spatial and Seasonal Variations of PM Concentration and Size Distribution in Manure-Belt Poultry Layer Houses

2019 ◽  
Vol 62 (2) ◽  
pp. 415-427 ◽  
Author(s):  
Reyna M. Knight ◽  
Xinjie Tong ◽  
Zhenyu Liu ◽  
Sewoon Hong ◽  
Lingying Zhao
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Distribution ◽  
Seasonal Variations ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Potential Health ◽  
Significant Difference ◽  
Autumn And Winter ◽  
Mass Concentrations

Abstract. Poultry layer houses are a significant source of particulate matter (PM) emissions, which potentially affect worker and animal health. Particulate matter characteristics, such as concentration and size distribution inside layer houses, are critical information for assessment of the potential health risks and development of effective PM mitigation technologies. However, this information and its spatial and seasonal variations are lacking for typical layer facilities. In this study, two TSI DustTrak monitors (DRX 8533) and an Aerodynamic Particle Sizer (APS 3321) were used to measure PM mass concentrations and number-weighted particle size distributions in two typical manure-belt poultry layer houses in Ohio in three seasons: summer, autumn, and winter. Bimodal particle size distributions were consistently observed. The average count median diameters (mean ±SD) were 1.68 ±0.25, 2.16 ±0.31, and 1.87 ±0.07 µm in summer, autumn, and winter, respectively. The average geometric standard deviations of particle size were 2.16 ±0.23, 2.16 ±0.18, and 1.74 ±0.17 in the three seasons, respectively. The average mass concentrations were 67.4 ±54.9, 289.9 ±216.2, and 428.1 ±269.9 µg m-3 for PM2.5; 73.6 ±59.5, 314.6 ±228.9, and 480.8 ±306.5 µg m-3 for PM4; and 118.8 ±99.6, 532.5 ±353.0, and 686.2 ±417.7 µg m-3 for PM10 in the three seasons, respectively. Both statistically significant (p &lt; 0.05) and practically significant (difference of means &gt;20% of smaller value) seasonal variations were observed. Spatial variations were only practically significant for autumn mass concentrations, likely due to external dust infiltration from nearby agricultural activities. The OSHA-mandated permissible exposure limit for respirable PM was not exceeded in any season. Keywords: Air quality, Particulate matter, Poultry housing, Seasonal variation, Spatial variation.

scholarly journals Particle number concentrations and size distribution in a polluted megacity: The Delhi Aerosol Supersite study

2020 ◽  
Author(s):  
Shahzad Gani ◽  
Sahil Bhandari ◽  
Kanan Patel ◽  
Sarah Seraj ◽  
Prashant Soni ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Ultrafine Particles ◽  
Particle Number ◽  
Fine Particulate Matter ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Time Resolved ◽  
Fine Particulate ◽  
National Capital ◽  
Order Of Magnitude

Abstract. The Indian national capital, Delhi, routinely experiences some of the world's highest urban particulate matter concentrations. While fine particulate matter (PM2.5) mass concentrations in Delhi are at least an order of magnitude higher than in many western cities, the particle number (PN) concentrations are not similarly elevated. Here we report on 1.25 years of highly time resolved particle size distributions (PSD) data in the size range of 12–560 nm. We observed that the large number of accumulation mode particles – that constitute most of the PM2.5 mass – also contributed substantially to the PN concentrations. The ultrafine particles (UFP, Dp 

scholarly journals Mobile measurements of ship emissions in two harbour areas in Finland

2014 ◽  
Vol 7 (1) ◽  
pp. 149-161 ◽  
Author(s):  
L. Pirjola ◽  
A. Pajunoja ◽  
J. Walden ◽  
J.-P. Jalkanen ◽  
T. Rönkkö ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Particle Number ◽  
City Centre ◽  
Particulate Emissions ◽  
Size Distributions ◽  
So2 Emissions ◽  
The Baltic Sea ◽  
Eu Directive ◽  
The Baltic ◽  
The City

Abstract. Four measurement campaigns were performed in two different environments – inside the harbour areas in the city centre of Helsinki, and along the narrow shipping channel near the city of Turku, Finland – using a mobile laboratory van during winter and summer conditions in 2010–2011. The characteristics of gaseous (CO, CO2, SO2, NO, NO2, NOx) and particulate (number and volume size distributions as well as PM2.5) emissions for 11 ships regularly operating on the Baltic Sea were studied to determine the emission parameters. The highest particle concentrations were 1.5 × 106 and 1.6 × 105 cm−3 in Helsinki and Turku, respectively, and the particle number size distributions had two modes. The dominating mode peaked at 20–30 nm, and the accumulation mode at 80–100 nm. The majority of the particle mass was volatile, since after heating the sample to 265 °C, the particle volume of the studied ship decreased by around 70%. The emission factors for NOx varied in the range of 25–100 g (kg fuel)−1, for SO2 in the range of 2.5–17.0 g (kg fuel)−1, for particle number in the range of (0.32–2.26) × 1016 # (kg fuel)−1, and for PM2.5 between 1.0–4.9 g (kg fuel)−1. The ships equipped with SCR (selective catalytic reduction) had the lowest NOx emissions, whereas the ships with DWI (direct water injection) and HAMs (humid air motors) had the lowest SO2 emissions but the highest particulate emissions. For all ships, the averaged fuel sulphur contents (FSCs) were less than 1% (by mass) but none of them was below 0.1% which will be the new EU directive starting 1 January 2015 in the SOx emission control areas; this indicates that ships operating on the Baltic Sea will face large challenges.

Mercury associated with size-fractionated urban particulate matter: three years of sampling in Prague, Czech Republic

2014 ◽  
Vol 68 (2) ◽  
Author(s):  
Ondřej Zvěřina ◽  
Pavel Coufalík ◽  
Josef Komárek ◽  
Petr Gadas ◽  
Jiřina Sysalová
Keyword(s):  
Czech Republic ◽  
Particulate Matter ◽  
Total Mercury ◽  
Wide Spectrum ◽  
Size Fraction ◽  
Mercury Content ◽  
Air Conditioner ◽  
Mercury Compounds ◽  
Suspended Particulate ◽  
The City

AbstractAn analysis of suspended particulate matter, with an emphasis on the Hg chemical forms, is presented. Dust samples originating from an area highly affected by traffic pollution in the city of Prague (Czech Republic) were sampled over a period of three years from air-conditioner filters and fractioned by size. The samples were morphologically characterised by scanning electron microscopy. The main method used for the analysis of constituent mercury compounds was sequential extraction by leaching solutions in combination with thermal desorption. The total mercury content ranged from 0.37 mg kg−1 to 0.82 mg kg−1. It emerged that the mercury was distributed in a wide spectrum of forms, and various trends in the distribution of these forms among the different size classes were observed. The fraction leached by nitric acid (consisting of elemental and complex-bound mercury) was the main constituent of total mercury. The highest content of this fraction was observed in the finest particle size class. The heterogeneity of morphology of the material increased with the size fraction.

scholarly journals Size-segregated particle number and mass concentrations from different emission sources in urban Beijing

2020 ◽  
Vol 20 (21) ◽  
pp. 12721-12740
Author(s):  
Jing Cai ◽  
Biwu Chu ◽  
Lei Yao ◽  
Chao Yan ◽  
Liine M. Heikkinen ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Source Apportionment ◽  
Particle Number ◽  
Fine Particles ◽  
Size Distributions ◽  
Vehicular Emissions ◽  
Particle Size Distributions ◽  
Chemical Fingerprints ◽  
Mass Concentrations

Abstract. Although secondary particulate matter is reported to be the main contributor of PM2.5 during haze in Chinese megacities, primary particle emissions also affect particle concentrations. In order to improve estimates of the contribution of primary sources to the particle number and mass concentrations, we performed source apportionment analyses using both chemical fingerprints and particle size distributions measured at the same site in urban Beijing from April to July 2018. Both methods resolved factors related to primary emissions, including vehicular emissions and cooking emissions, which together make up 76 % and 24 % of total particle number and organic aerosol (OA) mass, respectively. Similar source types, including particles related to vehicular emissions (1.6±1.1 µg m−3; 2.4±1.8×103 cm−3 and 5.5±2.8×103 cm−3 for two traffic-related components), cooking emissions (2.6±1.9 µg m−3 and 5.5±3.3×103 cm−3) and secondary aerosols (51±41 µg m−3 and 4.2±3.0×103 cm−3), were resolved by both methods. Converted mass concentrations from particle size distributions components were comparable with those from chemical fingerprints. Size distribution source apportionment separated vehicular emissions into a component with a mode diameter of 20 nm (“traffic-ultrafine”) and a component with a mode diameter of 100 nm (“traffic-fine”). Consistent with similar day- and nighttime diesel vehicle PM2.5 emissions estimated for the Beijing area, traffic-fine particles, hydrocarbon-like OA (HOA, traffic-related factor resulting from source apportionment using chemical fingerprints) and black carbon (BC) showed similar diurnal patterns, with higher concentrations during the night and morning than during the afternoon when the boundary layer is higher. Traffic-ultrafine particles showed the highest concentrations during the rush-hour period, suggesting a prominent role of local gasoline vehicle emissions. In the absence of new particle formation, our results show that vehicular-related emissions (14 % and 30 % for ultrafine and fine particles, respectively) and cooking-activity-related emissions (32 %) dominate the particle number concentration, while secondary particulate matter (over 80 %) governs PM2.5 mass during the non-heating season in Beijing.

scholarly journals Mobile measurements of ship emissions in two harbour areas in Finland

2013 ◽  
Vol 6 (4) ◽  
pp. 7149-7184
Author(s):  
L. Pirjola ◽  
A. Pajunoja ◽  
J. Walden ◽  
J.-P. Jalkanen ◽  
T. Rönkkö ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Particle Number ◽  
Particulate Emissions ◽  
Size Distributions ◽  
So2 Emissions ◽  
The Baltic Sea ◽  
Particle Volume ◽  
Eu Directive ◽  
The Baltic ◽  
The City

Abstract. Four measurement campaigns by a mobile laboratory van were performed in two different environments; inside the harbour areas in the city center of Helsinki and along the narrow shipping channel near the city of Turku, Finland, during the winter and summer conditions in 2010–2011. The characteristics of gaseous (CO, CO2, SO2, NO, NO2, NOx) and particulate (number and volume size distributions as well as PM2.5) emissions for 11 ships regularly operating on the Baltic Sea were studied to determine the emission parameters. The highest particle concentrations were 1.5 × 106 and 1.6 × 105 cm−3 in Helsinki and Turku, respectively, and the particle number size distributions had two modes. The dominating mode was peaking at 20–30 nm and the accumulation mode at 80–100 nm. The majority of the particle mass was volatile since after heating the sample to 265 °C, the particle volume of the studied ships decreased by around 70%. The emission factors for NOx varied in the range of 25–100 g (kg fuel)−1, for SO2 in the range of 2.5–17.0 g (kg fuel)−1, for particle number in the range of (0.32–2.26) × 1016 particles (kg fuel)−1, and for PM2.5 between 1.0–4.9 g (kg fuel)−1. The ships equipped with SCR had lowest NOx emissions whereas the ships with DWI and HAM had lowest SO2 emissions but highest particulate emissions. For all ships the averaged fuel sulphur contents (FSCs) were less than 1% (by mass) but none of those was below 0.1% which will be the new EU directive from 1 January 2015 in the SOx Emission Control Areas, indicating big challenges for ships operating on the Baltic Sea.

scholarly journals In situ formation and spatial variability of particle number concentration in a European megacity

2015 ◽  
Vol 15 (17) ◽  
pp. 10219-10237 ◽  
Author(s):  
M. Pikridas ◽  
J. Sciare ◽  
F. Freutel ◽  
S. Crumeyrolle ◽  
S.-L. von der Weiden-Reinmüller ◽  
...  
Keyword(s):  
Particle Number ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Size Distributions ◽  
City Center ◽  
Ambient Particle ◽  
In Situ Formation ◽  
The City ◽  
Suburban Site

Abstract. Ambient particle number size distributions were measured in Paris, France, during summer (1–31 July 2009) and winter (15 January to 15 February 2010) at three fixed ground sites and using two mobile laboratories and one airplane. The campaigns were part of the Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation (MEGAPOLI) project. New particle formation (NPF) was observed only during summer on approximately 50 % of the campaign days, assisted by the low condensation sink (about 10.7 ± 5.9 × 10−3 s−1). NPF events inside the Paris plume were also observed at 600 m altitude onboard an aircraft simultaneously with regional events identified on the ground. Increased particle number concentrations were measured aloft also outside of the Paris plume at the same altitude, and were attributed to NPF. The Paris plume was identified, based on increased particle number and black carbon concentration, up to 200 km away from the Paris center during summer. The number concentration of particles with diameters exceeding 2.5 nm measured on the surface at the Paris center was on average 6.9 ± 8.7 × 104 and 12.1 ± 8.6 × 104 cm−3 during summer and winter, respectively, and was found to decrease exponentially with distance from Paris. However, further than 30 km from the city center, the particle number concentration at the surface was similar during both campaigns. During summer, one suburban site in the NE was not significantly affected by Paris emissions due to higher background number concentrations, while the particle number concentration at the second suburban site in the SW increased by a factor of 3 when it was downwind of Paris.

scholarly journals Size segregated particle number and mass emissions in urban Beijing

2020 ◽  
Author(s):  
Jing Cai ◽  
Biwu Chu ◽  
Lei Yao ◽  
Chao Yan ◽  
Liine M. Heikkinen ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Source Apportionment ◽  
Particle Number ◽  
Related Factor ◽  
Size Distributions ◽  
Vehicular Emissions ◽  
Particle Size Distributions ◽  
Chemical Fingerprints ◽  
Mass Concentrations

Abstract. Although secondary particulate matter is reported to be the main contributor of PM2.5 during haze in Chinese megacities, primary particle emissions also affect particle concentrations. In order to improve estimates of the contribution of primary sources to the particle number and mass concentrations, we performed source apportionment analyses using both chemical fingerprints and particle size distributions measured at the same site in urban Beijing from April to July 2018. Both methods resolved factors related to primary emissions, including vehicular emissions and cooking emissions, which together make up 76 % and 24 % of total particle number and organic aerosol (OA) mass, respectively. Similar source-types, including particles related to vehicular emissions (1.6 ± 1.1 μg m−3; 2.4 ± 1.8 × 103 cm−3 and 5.5 ± 2.8 × 103 cm−3 for two traffic-related components), cooking emissions (2.6 ± 1.9 μg m−3 and 5.5 ± 3.3 × 103 cm−3) and secondary aerosols (51 ± 41 μg m−3 and 4.2 ± 3.0 × 103 cm−3) were resolved by both methods. Converted mass concentrations from particle size distributions components were comparable with those from chemical fingerprints. Size distribution source apportionment separated vehicular emissions into a component with a mode diameter of 20 nm (Traffic-ultrafine) and a component with a mode diameter of 100 nm (Traffic-fine). Consistent with similar day and night-time diesel vehicle PM2.5 emissions estimated for the Beijing area, Traffic-fine, hydrocarbon-like OA (HOA, traffic-related factor resulting from source apportionment using chemical fingerprints), and black carbon (BC) showed similar diurnal patterns, with higher concentrations during the night and morning than during the afternoon when the boundary layer is higher. Traffic-ultrafine particles showed the highest concentrations during the rush-hour period, suggesting a prominent role of local gasoline vehicle emissions. In the absence of new-particle formation, our results show that vehicular (14 % and 30 % for ultrafine and fine particles, respectively) and cooking (32 %) emissions dominate the particle number concentration while secondary particulate matter (over 80 %) governs PM2.5 mass during the non-heating season in Beijing.

scholarly journals Effects of marine fuel sulfur restrictions on particle number concentrations and size distributions in ship plumes at the Baltic Sea

2020 ◽  
Author(s):  
Sami Seppälä ◽  
Joel Kuula ◽  
Antti-Pekka Hyvärinen ◽  
Sanna Saarikoski ◽  
Topi Rönkkö ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Particle Number ◽  
Uv Light ◽  
Ambient Air ◽  
Small Island ◽  
Distribution Data ◽  
Size Distributions ◽  
The Baltic Sea ◽  
Marine Fuel ◽  
The Baltic

Abstract. Exhaust emissions from shipping are a major contributor to particle concentrations in coastal and marine areas. Previously, marine fuel sulfur content (FSC) was restricted globally to 4.5 m/m% but the limit was changed to 3.5 m/m% at the beginning of 2012 and further down to 0.5 m/m% in January 2020. In sulfur emission control areas (SECA), the limits are stricter; FSC restriction was originally 1.50 m/m% but it decreased first to 1.00 m/m% in July 2010 and again to 0.10 m/m% in January 2015. In this work, the effects of the FSC restrictions on particle number concentrations (PNC) and size distributions (NSD) are studied at the Baltic Sea SECA. Measurements were made on a small island (Utö, Finland; 59° 46’50N, 21° 22’23E) between 2007 and 2016. Ship plumes were extracted from the particle number size distribution data, and the effects of the FSC restrictions on the observed plumes as well as on the total ambient concentrations were investigated. Altogether 42 322 analyzable plumes were identified during the 10-year measurement period. The results showed that both changes in the FSC restrictions reduced the PNC of the plumes. The latter restriction (to 0.10 m/m% in January 2015) decreased also the total ambient particle number concentrations, as a significant portion of particles in the area originated from ship plumes that were diluted beyond the plume detection limits. The overall change in the PNC of the plumes and ambient air was 27 and 32 %, respectively, for the total FSC change from 1.50 to 0.10 m/m%. The decrease in plume particle number concentration was caused mostly by a decrease in the concentration of particle sizes of ∼35–134 nm. The latter restriction also reduced the count median diameter of the particles, which was probably caused by the fuel type change from residual oil to distillates during the latter restriction. The PNC was larger for the plumes measured in daytime compared to those measured in nighttime likely because of the photochemical aging of particles due to UV-light. The difference decreased with the reducing FSC indicating that lower FSC has also an impact on the atmospheric processing of ship plumes.

scholarly journals Ultrafine particle sources and in-situ formation in a European megacity

2015 ◽  
Vol 15 (4) ◽  
pp. 5663-5712 ◽  
Author(s):  
M. Pikridas ◽  
J. Sciare ◽  
F. Freutel ◽  
S. Crumeyrolle ◽  
S.-L. von der Weiden-Reinmüller ◽  
...  
Keyword(s):  
Particle Number ◽  
Ultrafine Particle ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Size Distributions ◽  
City Center ◽  
Ambient Particle ◽  
The City ◽  
Suburban Site

Abstract. Ambient particle number size distributions were measured in Paris, France during summer (1–31 July 2009) and winter (15 January–15 February 2010) at three fixed ground sites and using two mobile laboratories and one airplane. The campaigns were part of the MEGAPOLI project. New particle formation (NPF) was observed only during summer at approximately 50% of the campaign days, assisted by the low condensation sink (about 10.7 ± 5.9 × 10−3 s−1). NPF events inside the Paris plume were also observed at 600 m altitude onboard an aircraft simultaneously with regional events identified on the ground. Increased particle number concentrations were measured aloft also outside of the Paris plume at the same altitude, and were attributed to NPF. The Paris plume was identified, based on increased particle number and black carbon concentration, up to 200 km away from Paris center during summer. The number concentration of particles with diameter exceeding 2.5 nm measured on the surface at Paris center was on average 6.9 ± 8.7 × 104 and 12.1 ± 8.6 × 104 cm−3 during summer and winter, respectively, and was found to decrease exponentially with distance from Paris. However, further than 30 km from the city center, the particle number concentration at the surface was similar during both campaigns. During summer one suburban site in the NE was not significantly affected by Paris emissions due to higher background number concentrations, while the particle number concentration at the second suburban site in the SW increased by a factor of three when it was downwind of Paris.

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