scholarly journals Emissions of organic aerosol mass, black carbon, particle number, and regulated and unregulated gases from scooters and light and heavy duty vehicles with different fuels

2014 ◽  
Vol 14 (11) ◽  
pp. 16591-16639 ◽  
Author(s):  
R. Chirico ◽  
M. Clairotte ◽  
T. W. Adam ◽  
B. Giechaskiel ◽  
M. F. Heringa ◽  
...  

Abstract. A sampling campaign with seven different types of vehicles was conducted in 2009 at the vehicle test facilities of the Joint Research Centre (JRC) in Ispra (Italy). The vehicles chosen were representative of some categories circulating in Europe and were fueled either with standard gasoline or diesel and some with blends of rapeseed methyl ester biodiesel. The aim of this work was to improve the knowledge about the emission factors of gas phase and particle-associated regulated and unregulated species from vehicle exhaust. Unregulated species such as black carbon (BC), primary organic aerosol (OA) content, particle number (PN), monocyclic and polycyclic aromatic hydrocarbons (PAHs) and a~selection of unregulated gaseous compounds, including nitrous acid (N2O), ammonia (NH3), hydrogen cyanide (HCN), formaldehyde (HCHO), acetaldehyde (CH3CHO), sulfur dioxide (SO2), and methane (CH4), were measured in real time with a suite of instruments including a high-resolution aerosol time-of-flight mass spectrometer, a resonance enhanced multi-photon ionization time-of-flight mass spectrometer, and a high resolution Fourier transform infrared spectrometer. Diesel vehicles, without particle filters, featured the highest values for particle number, followed by gasoline vehicles and scooters. The particles from diesel and gasoline vehicles were mostly made of BC with a low fraction of OA, while the particles from the scooters were mainly composed of OA. Scooters were characterized by super high emissions factors for OA, which were orders of magnitude higher than for the other vehicles. The heavy duty diesel vehicle (HDDV) featured the highest nitrogen oxides (NOx) emissions, while the scooters had the highest emissions for total hydrocarbons and aromatic compounds due to the unburned and partially burned gasoline and lubricant oil mixture. Generally, vehicles fuelled with biodiesel blends showed lower emission factors of OA and total aromatics than those from the standard fuels. The scooters were the main emitters of aromatic compounds, followed by the gasoline vehicle, the diesel vehicles and the HDDV.

2020 ◽  
Author(s):  
Yunle Chen ◽  
Masayuki Takeuchi ◽  
Theodora Nah ◽  
Lu Xu ◽  
Manjula R. Canagaratna ◽  
...  

Abstract. The formation and evolution of secondary organic aerosol (SOA) was investigated at Yorkville, GA, in late summer (mid-August ~ mid-October, 2016). Organic aerosol (OA) composition was measured using two on-line mass spectrometry instruments, the high-resolution time-of-flight aerosol mass spectrometer (AMS) and the Filter Inlet for Gases and AEROsols coupled to a high-resolution time-of-flight iodide-adduct chemical ionization mass spectrometer (FIGAERO-CIMS). Through analysis of speciated organics data from FIGAERO-CIMS and factorization analysis of data obtained from both instruments, we observed notable SOA formation from isoprene and monoterpenes during both day and night. Specifically, in addition to isoprene epoxydiols (IEPOX) uptake, we identified isoprene SOA formation via hydroxyl hydroperoxide oxidation (ISOPOOH oxidation via non-IEPOX pathways) and isoprene organic nitrate formation via photooxidation in the presence of NOx and nitrate radical oxidation. Monoterpenes were found to be the most important SOA precursors at night. We observed significant contributions from highly-oxidized acid-like compounds to the aged OA factor from FIGAERO-CIMS. Taken together, our results showed that FIGAERO-CIMS measurements are highly complementary to the extensively used AMS factorization analysis, and together they provide more comprehensive insights into OA sources and composition.


2019 ◽  
Vol 19 (18) ◽  
pp. 11687-11700 ◽  
Author(s):  
Wei Huang ◽  
Harald Saathoff ◽  
Xiaoli Shen ◽  
Ramakrishna Ramisetty ◽  
Thomas Leisner ◽  
...  

Abstract. The chemical composition and volatility of organic aerosol (OA) particles were investigated during July–August 2017 and February–March 2018 in the city of Stuttgart, one of the most polluted cities in Germany. Total non-refractory particle mass was measured with a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS; hereafter AMS). Aerosol particles were collected on filters and analyzed in the laboratory with a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-HR-ToF-CIMS; hereafter CIMS), yielding the molecular composition of oxygenated OA (OOA) compounds. While the average organic mass loadings are lower in the summer period (5.1±3.2 µg m−3) than in the winter period (8.4±5.6 µg m−3), we find relatively larger mass contributions of organics measured by AMS in summer (68.8±13.4 %) compared to winter (34.8±9.5 %). CIMS mass spectra show OOA compounds in summer have O : C of 0.82±0.02 and are more influenced by biogenic emissions, while OOA compounds in winter have O : C of 0.89±0.06 and are more influenced by biomass burning emissions. Volatility parametrization analysis shows that OOA in winter is less volatile with higher contributions of low-volatility organic compounds (LVOCs) and extremely low-volatility organic compounds (ELVOCs). We partially explain this by the higher contributions of compounds with shorter carbon chain lengths and a higher number of oxygen atoms, i.e., higher O : C in winter. Organic compounds desorbing from the particles deposited on the filter samples also exhibit a shift of signal to higher desorption temperatures (i.e., lower apparent volatility) in winter. This is consistent with the relatively higher O : C in winter but may also be related to higher particle viscosity due to the higher contributions of larger-molecular-weight LVOCs and ELVOCs, interactions between different species and/or particles (particle matrix), and/or thermal decomposition of larger molecules. The results suggest that whereas lower temperature in winter may lead to increased partitioning of semi-volatile organic compounds (SVOCs) into the particle phase, this does not result in a higher overall volatility of OOA in winter and that the difference in sources and/or chemistry between the seasons plays a more important role. Our study provides insights into the seasonal variation of the molecular composition and volatility of ambient OA particles and into their potential sources.


2019 ◽  
Author(s):  
Wei Huang ◽  
Harald Saathoff ◽  
Xiaoli Shen ◽  
Ramakrishna Ramisetty ◽  
Thomas Leisner ◽  
...  

Abstract. Chemical composition and volatility of organic aerosol (OA) particles were investigated during July–August 2017 and February–March 2018 in the city of Stuttgart, one of the most polluted cities in Germany. Total non-refractory particle mass was measured with a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS; hereafter AMS). Aerosol particles were collected on filters and analyzed in the laboratory with a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-HR-ToF-CIMS; hereafter CIMS), yielding the molecular composition of oxygenated OA (OOA) compounds. While the average organic mass loadings are lower in the summer period (5.1 ± 3.2 µg m−3) than in the winter period (8.4 ± 5.6 µg m−3), we find relatively larger mass contributions of organics measured by AMS in summer (68.8 ± 13.4 %) compared to winter (34.8 ± 9.5 %). CIMS mass spectra show OOA compounds in summer have O : C ratios of 0.82 ± 0.02 and are more influenced by biogenic emissions, while OOA compounds in winter have O : C ratios of 0.89 ± 0.06 and are more influenced by biomass burning emissions. Volatility parametrization analysis shows that OOA in winter is less volatile with higher contributions of low volatile organic compounds (LVOC) and extremely low volatile organic compounds (ELVOC). We partially explain this by the higher contributions of compounds with shorter carbon chain lengths and higher number of oxygen atoms, i.e. higher O : C ratios in winter. Organic compounds desorbing from the particles deposited on the filter samples also exhibit a shift of signal to higher desorption temperatures (i.e. lower apparent volatility) in winter. This is consistent with the relatively higher O : C ratios in winter, but may also be related to higher particle viscosity due to the higher contributions of larger molecular-weight LVOC and ELVOC, interactions between different species and/or particles (particle matrix), and/or thermal decomposition of larger molecules. The results suggest that whereas lower temperature in winter may lead to increased partitioning of semi-volatile organic compounds (SVOC) into the particle phase, this does not result in a higher overall volatility of OOA in winter, and that the difference in sources and/or chemistry between the seasons plays a more important role. Our study provides insights into the seasonal variation of molecular composition and volatility of ambient OA particles, and into their potential sources.


2020 ◽  
Vol 20 (14) ◽  
pp. 8421-8440
Author(s):  
Yunle Chen ◽  
Masayuki Takeuchi ◽  
Theodora Nah ◽  
Lu Xu ◽  
Manjula R. Canagaratna ◽  
...  

Abstract. The formation and evolution of secondary organic aerosol (SOA) were investigated at Yorkville, GA, in late summer (mid-August to mid-October 2016). The organic aerosol (OA) composition was measured using two online mass spectrometry instruments, the high-resolution time-of-flight aerosol mass spectrometer (AMS) and the Filter Inlet for Gases and AEROsols coupled to a high-resolution time-of-flight iodide-adduct chemical ionization mass spectrometer (FIGAERO-CIMS). Through analysis of speciated organics data from FIGAERO-CIMS and factorization analysis of data obtained from both instruments, we observed notable SOA formation from isoprene and monoterpenes during both day and night. Specifically, in addition to isoprene epoxydiol (IEPOX) uptake, we identified isoprene SOA formation from non-IEPOX pathways and isoprene organic nitrate formation via photooxidation in the presence of NOx and nitrate radical oxidation. Monoterpenes were found to be the most important SOA precursors at night. We observed significant contributions from highly oxidized acid-like compounds to the aged OA factor from FIGAERO-CIMS. Taken together, our results showed that FIGAERO-CIMS measurements are highly complementary to the extensively used AMS factorization analysis, and together they provide more comprehensive insights into OA sources and composition.


2021 ◽  
Author(s):  
feng jiang ◽  
Harald Saathoff ◽  
junwei song ◽  
linyu gao ◽  
magdalena vallon ◽  
...  

<p>Brown carbon (BrC) aerosol has significant climatic impact due to its ability to absorb solar radiation in the near-ultraviolet and visible spectral range. However, chromophores responsible for light absorption in atmospheric aerosol particles are not well understood in urban areas. Therefore, optical properties and chromophore composition of brown carbon were characterized during March 2020 in downtown Karlsruhe, a city of 300000 inhabitants in southwest Germany.</p><p>In this study, total non-refractory particle mass was measured with a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-MS; hereafter AMS). Furthermore, Aerosol particles were collected on filters and analyzed in the laboratory. Filter samples were extracted by methanol and the corresponding solutions were analyzed by excitation-emission spectroscopy (AquaLog), resulting in characteristic light absorption and fluorescence spectra. Furthermore, filters were analyzed by a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-HR-TOF-CIMS; hereafter CIMS) employing iodide ions, which results in the molecular composition of oxygenated organic aerosol compounds.</p><p>Our results show that the average light absorption and mass absorption efficiency of brown carbon at 365 nm were (2.8±1.9) Mm<sup>-1</sup> and (1.1±0.2) m<sup>2</sup> g<sup>-1</sup> respectively. Parallel factor (PARAFAC) analysis allowed for identification of four types of fluorescence in methanol-soluble organic compounds. HULIS-like compounds contributed 47%, road dust-like compounds 19%, biomass burning-like compounds 25%, and protein-like compounds 9%. Positive matrix factorization (PMF) analysis of organic detected by AMS led to five characteristic organic compound classes. Of these five classes, the biomass burning organic aerosol showed a correlation coefficient of r2=0.7 with the biomass burning like factor from the fluorescence analysis. Oxygenated organic aerosol components had potentially lower fluorescence intensity and mass absorption coefficiency. Furthermore, five nitroaromatic compounds were identified by CIMS (C7H7O3N, C7H7O4N, C6H5O5N, C6H5O4N, and C6H5O3N) which contributed 0.2%-0.9% to total organic mass, but can explain 3%-6% of the absorption at 365 nm.</p>


2010 ◽  
Vol 10 (10) ◽  
pp. 22669-22723 ◽  
Author(s):  
Y.-L. Sun ◽  
Q. Zhang ◽  
J. J. Schwab ◽  
K. L. Demerjian ◽  
W.-N. Chen ◽  
...  

Abstract. Submicron aerosol particles (PM1) were measured in-situ using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) during the summer 2009 Field Intensive Study at Queens College in New York City. Organic aerosol (OA) and sulfate are the two dominant species, accounting for 54% and 24%, respectively, of total PM1 mass on average. The average mass size distribution of OA presents a small mode peaking at ~150 nm (Dva) in addition to an accumulation mode (~550 nm) that is internally mixed with sulfate, nitrate, and ammonium. The diurnal cycles of sulfate and OA both show pronounced peaks between 01:00–02:00 p.m. EST due to photochemical production. The average (±1σ) oxygen-to-carbon (O/C), hydrogen-to-carbon (H/C), and nitrogen-to-carbon (N/C) ratios of OA in NYC are 0.36 (±0.09), 1.49 (±0.08), and 0.012(±0.005), respectively, corresponding to an average organic mass-to-carbon (OM/OC) ratio of 1.62(±0.11). Positive matrix factorization (PMF) of the high resolution mass spectra identified five OA components: a hydrocarbon-like OA (HOA), two types of oxygenated OA (OOA) including a low-volatility OOA (LV-OOA) and a semi-volatile OOA (SV-OOA), a cooking-emission related OA (COA), and a unique nitrogen-enriched OA (NOA). HOA appears to represent primary OA (POA) from urban traffic emissions. It comprises primarily of reduced species (H/C=1.83; O/C=0.06) and shows a mass spectral pattern very similar to those of POA from fossil fuel combustion, and correlates tightly with traffic emission tracers including elemental carbon and NOx. LV-OOA, which is highly oxidized (O/C=0.63) and correlates well with sulfate, appears to be representative for regional, aged secondary OA (SOA). SV-OOA, which is less oxidized (O/C=0.38) and correlates well with non-refractory chloride, likely represents less photo-chemically aged, semi-volatile SOA. COA shows a similar spectral pattern to the reference spectra of POA from cooking emissions and a distinct diurnal pattern peaking around local lunch and dinner times. In addition, NOA is characterized with prominent CxH2x+2N+ peaks likely from amine compounds. Our results indicate that cooking-related activities are a major source of POA in NYC, releasing comparable amounts of POA as traffic emissions. POA=HOA+COA) on average accounts for ~30% of the total OA mass during this study while SOA dominates the OA composition with SV-OOA and LV-OOA on average accounting for 34% and 30%, respectively, of the total OA mass. The chemical evolution of SOA in NYC involves a~continuous oxidation from SV-OOA to LV-OOA, which is further supported by a gradual increase of O/C ratio and a simultaneous decrease of H/C ratio in total OOA. Detailed analysis of NOA (5.8% of OA) presents evidence that nitrogen-containing organic species such as amines might have played an important role in the atmospheric processing of OA in NYC, likely involving acid-base chemistry. Analysis of air mass trajectories and satellite imagery of aerosol optical depth (AOD) indicates that the high potential source regions of secondary sulfate and aged OA are mainly located in regions to the west and southwest of the city.


2020 ◽  
Vol 10 (17) ◽  
pp. 5856
Author(s):  
Gyutae Park ◽  
Kyunghoon Kim ◽  
Taehyun Park ◽  
Seokwon Kang ◽  
Jihee Ban ◽  
...  

With global anthropogenic black carbon (BC) emissions increasing, automobiles are significantly contributing as the major source of emissions. However, the appropriate regulations of BC emissions from vehicles are not in place. This study examined BC emissions following fuel types (gasoline, liquefied petroleum gas (LPG), and diesel) and engine combustion (gasoline direct injection (GDI) and multi-port injection (MPI) for gasoline vehicles) with emission regulations. To this end, chassis dynamometer and aethalometer (AE33) were used. Driving modes created by the National Institute of Environmental Research (NIER) and emission certification modes (CVS-75 and NEDC) for vehicles in Korea were used to determine BC emissions for various vehicle speeds. In addition, the contributions of biomass and coal combustion to the data of AE33 were analyzed to determine the possibility of tracking the BC sources. MPI, LPG, and EURO 6 with diesel particulate filter (DPF) vehicles emitted the lowest BC emissions in NIER modes. Among gasoline vehicles, MPI vehicles showed the lower BC content in PM emissions. Also, older vehicles in MPI vehicles emitted the high PM and BC emissions. The BC emissions of EURO 3 vehicles without DPF were the highest as the results of previous studies, and it was found that as emissions regulations were tightened, the level of BC results of diesel vehicles became similar with MPI vehicles. The average absorption Ångström exponent (AAE) from difference emissions sources were biomass combustion (oak wood) > coal combustion (the power plant stack) > automobile emissions (gasoline, LPG, diesel).


2019 ◽  
Vol 19 (12) ◽  
pp. 8037-8062 ◽  
Author(s):  
Lu Qi ◽  
Mindong Chen ◽  
Giulia Stefenelli ◽  
Veronika Pospisilova ◽  
Yandong Tong ◽  
...  

Abstract. Real-time, in situ molecular composition measurements of the organic fraction of fine particulate matter (PM2.5) remain challenging, hindering a full understanding of the climate impacts and health effects of PM2.5. In particular, the thermal decomposition and ionization-induced fragmentation affecting current techniques has limited a detailed investigation of secondary organic aerosol (SOA), which typically dominates OA. Here we deploy a novel extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF-MS) during winter 2017 in downtown Zurich, Switzerland, which overcomes these limitations, together with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and supporting instrumentation. Positive matrix factorization (PMF) implemented within the Multilinear Engine (ME-2) program was applied to the EESI-TOF-MS data to quantify the primary and secondary contributions to OA. An 11-factor solution was selected as the best representation of the data, including five primary and six secondary factors. Primary factors showed influence from cooking, cigarette smoke, biomass burning (two factors) and a special local unknown event occurred only during two nights. Secondary factors were affected by biomass burning (three factors, distinguished by temperature and/or wind direction), organonitrates, monoterpene oxidation, and undetermined regional processing, in particular the contributions of wood combustion. While the AMS attributed slightly over half the OA mass to SOA but did not identify its source, the EESI-TOF-MS showed that most (>70 %) of the SOA was derived from biomass burning. Together with significant contributions from less aged biomass burning factors identified by both AMS and EESI-TOF-MS, this firmly establishes biomass burning as the single most important contributor to OA mass at this site during winter. High correlation was obtained between EESI-TOF-MS and AMS PMF factors where specific analogues existed, as well as between total signal and POA–SOA apportionment. This suggests the EESI-TOF-MS apportionment in the current study can be approximately taken at face value, despite ion-by-ion differences in relative sensitivity. The apportionment of specific ions measured by the EESI-TOF-MS (e.g., levoglucosan, nitrocatechol, and selected organic acids) and utilization of a cluster analysis-based approach to identify key marker ions for the EESI-TOF-MS factors are investigated. The interpretability of the EESI-TOF-MS results and improved source separation relative to the AMS within this pilot campaign validate the EESI-TOF-MS as a promising approach to source apportionment and atmospheric composition research.


Sign in / Sign up

Export Citation Format

Share Document