IVL Swedish Environmental Research Institute

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  • 1.
    Hallquist, Åsa
    IVL Swedish Environmental Research Institute.
    Chlorine oxidation of VOCs at a semi-rural site in Beijing: significant chlorine liberation from ClNO2 and subsequent gas- and particle-phase Cl–VOC production, Atmos.2018In: Chemical Physics, ISSN 0301-0104, E-ISSN 1873-4421, no 18, p. 13013-13030Article in journal (Refereed)
    Abstract [en]

    Nitryl chloride (ClNO2) accumulation at night acts as a significant reservoir for active chlorine and impacts the following day's photochemistry when the chlorine atom is liberated at sunrise. Here, we report simultaneous measurements of N2O5 and a suite of inorganic halogens including ClNO2 and reactions of chloride with volatile organic compounds (Cl–VOCs) in the gas and particle phases utilising the Filter Inlet for Gas and AEROsols time-of-flight chemical ionisation mass spectrometer (FIGAERO-ToF-CIMS) during an intensive measurement campaign 40km northwest of Beijing in May and June 2016. A maximum mixing ratio of 2900ppt of ClNO2 was observed with a mean campaign nighttime mixing ratio of 487ppt, appearing to have an anthropogenic source supported by correlation with SO2, CO and benzene, which often persisted at high levels after sunrise until midday. This was attributed to such high mixing ratios persisting after numerous e-folding times of the photolytic lifetime enabling the chlorine atom production to reach 2.3 × 105moleculescm−3 from ClNO2 alone, peaking at 09:30LT and up to 8.4 × 105moleculescm−3 when including the supporting inorganic halogen measurements.

  • 2.
    Hallquist, Åsa
    IVL Swedish Environmental Research Institute.
    Online gas- and particle-phase measurements of organosulfates, organosulfonates and nitrooxy organosulfates in Beijing utilizing a FIGAERO ToF-CIMS2018In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, no 18, p. 10355-10371Article in journal (Refereed)
    Abstract [en]

    A time-of-flight chemical ionization mass spectrometer (CIMS) utilizing the Filter Inlet for Gas and Aerosol (FIGAERO) was deployed at a regional site 40km north-west of Beijing and successfully identified and measured 17 sulfur-containing organics (SCOs are organo/nitrooxy organosulfates and sulfonates) with biogenic and anthropogenic precursors. The SCOs were quantified using laboratory-synthesized standards of lactic acid sulfate and nitrophenol organosulfate (NP OS). The variation in field observations was confirmed by comparison to offline measurement techniques (orbitrap and high-performance liquid chromatography, HPLC) using daily averages. The mean total (of the 17 identified by CIMS) SCO particle mass concentration was 210±110ngm−3 and had a maximum of 540ngm−3, although it contributed to only 2±1% of the organic aerosol (OA). The CIMS identified a persistent gas-phase presence of SCOs in the ambient air, which was further supported by separate vapour-pressure measurements of NP OS by a Knudsen Effusion Mass Spectrometer (KEMS). An increase in relative humidity (RH) promoted partitioning of SCO to the particle phase, whereas higher temperatures favoured higher gas-phase concentrations.

    Biogenic emissions contributed to only 19% of total SCOs measured in this study. Here, C10H16NSO7, a monoterpene-derived SCO, represented the highest fraction (10%) followed by an isoprene-derived SCO. The anthropogenic SCOs with polycyclic aromatic hydrocarbon (PAH) and aromatic precursors dominated the SCO mass loading (51%) with C11H11SO7, derived from methyl naphthalene oxidation, contributing to 40ngm−3 and 0.3% of the OA mass. Anthropogenic-related SCOs correlated well with benzene, although their abundance depended highly on the photochemical age of the air mass, tracked using the ratio between pinonic acid and its oxidation product, acting as a qualitative photochemical clock. In addition to typical anthropogenic and biogenic precursors the biomass-burning precursor nitrophenol (NP) provided a significant level of NP OS. It must be noted that the contribution analysis here is only representative of the detected SCOs. There are likely to be many more SCOs present which the CIMS has not identified.

    Gas- and particle-phase measurements of glycolic acid suggest that partitioning towards the particle phase promotes glycolic acid sulfate production, contrary to the current formation mechanism suggested in the literature. Furthermore, the HSO4 ⋅ H2SO4− cluster measured by the CIMS was utilized as a qualitative marker for acidity and indicates that the production of total SCOs is efficient in highly acidic aerosols with high SO42− and organic content. This dependency becomes more complex when observing individual SCOs due to variability of specific VOC precursors.

  • 3.
    Hallquist, Åsa
    IVL Swedish Environmental Research Institute.
    Ozone and OH-induced oxidation of monoterpenes: Changes in the thermal properties of secondary organic aerosol (SOA)2017In: Journal of Aerosol Science, ISSN 0021-8502, E-ISSN 1879-1964, no 114, p. 31-41Article in journal (Refereed)
    Abstract [en]

    The behaviour of secondary organic aerosols (SOA) in the atmosphere is highly dependent on their thermal properties. Here we investigate the volatility of SOA formed from α-pinene, β-pinene and limonene upon ozone- and OH-induced oxidation, and the effect of OH-induced ageing on the initially produced SOA. For all three terpenes, the ozone-induced SOA was less volatile than the OH-induced SOA. The thermal properties of the SOA were described using three parameters extracted from the volatility measurements: the temperature at which 50% of the volume has evaporated (TVFR0.5), which is used as a general volatility indicator; a slope factor (SVFR), which describes the volatility distribution; and TVFR0.1, which measures the volatility of the least volatile particle fraction.

    Limonene-derived SOA generally had higher TVFR0.5 values and shallower slopes than SOA derived from α- and β-pinene. This was especially true for the ozone-induced SOA, partially because the ozonolysis of limonene has a strong tendency to cause SOA formation and to produce extremely low volatility VOCs (ELVOCs). Ageing by OH exposure did not reduce TVFR0.5 for any of the studied terpenes but did increase the breadth of the volatility distribution by increasing the aerosols’ heterogeneity and contents of substances with different vapour pressures, also leading to increases in TVFR0.1.

    This stands in contrast to previously reported results from smog chamber experiments, in which TVFR0.5 always increased with ageing. These results demonstrate that there are two opposing processes that influence the evolution of SOAs’ thermal properties as they age, and that results from both flow reactors and static chambers are needed to fully understand the temporal evolution of atmospheric SOA’ thermal properties.

  • 4.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Fallgren, Henrik
    IVL Swedish Environmental Research Institute.
    Jerksjö, Martin
    IVL Swedish Environmental Research Institute.
    Jutterström, Sara
    IVL Swedish Environmental Research Institute.
    Liua, Qianyun
    Salberg, Håkan
    IVL Swedish Environmental Research Institute.
    Hallquist, Mattias
    Le Breton, Michael
    Pei, Xiangyu
    Kant Pathak, Ravi
    Liu, Tengyu
    Lee, Berto
    K. Chan, Chak
    Roadside assessment of a modern city bus fleet: Gaseous and particle emissions2019In: Atmospheric Environment: X, ISSN 2590-1621Article in journal (Refereed)
  • 5.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Garmash, Olga
    P. Rissanen, Matti
    Pullinen, Iida
    Schmitt, Sebastian
    Kausiala, Oskari
    Tillmann, Ralf
    Zhao, Defeng
    Percival, Carl
    J. Bannan, Thomas
    Priestley, Michael
    Kleist, Einhard
    Kiendler-Scharr, Astrid
    Hallquist, Mattias
    Berndt, Torsten
    McFiggans, Gordon
    Wildt, Jürgen
    F. Mentel, Thomas
    Ehn, Mikael
    Multi-generation OH oxidation as a source for highly oxygenated organic molecules from aromatics2019In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324Article in journal (Refereed)
  • 6.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Jerksjö, Martin
    IVL Swedish Environmental Research Institute.
    Fallgren, Henrik
    IVL Swedish Environmental Research Institute.
    Jutterström, Sara
    IVL Swedish Environmental Research Institute.
    Fresh and Oxidized Emissions from In-Use Transit Buses Running on Diesel, Biodiesel, and CNG2018Article in journal (Refereed)
    Abstract [en]

    The potential effect of changing to a nonfossil fuel vehicle fleet was investigated by measuring primary emissions (by extractive sampling of bus plumes) and secondary mass formation, using a Gothenburg Potential Aerosol Mass (Go:PAM) reactor, from 29 in-use transit buses. Regarding fresh emissions, diesel (DSL) buses without a diesel particulate filter (DPF) emitted the highest median mass of particles, whereas compressed natural gas (CNG) buses emitted the lowest (MdEFPM 514 and 11 mg kg fuel–1, respectively).

    Rapeseed methyl ester (RME) buses showed smaller MdEFPM and particle sizes than DSL buses. DSL (no DPF) and hybrid-electric RME (RMEHEV) buses exhibited the highest particle numbers (MdEFPN 12 × 1014 # kg fuel–1). RMEHEV buses displayed a significant nucleation mode (Dp< 20 nm). EFPN of CNG buses spanned the highest to lowest values measured. Low MdEFPN and MdEFPM were observed for a DPF-equipped DSL bus.

    Secondary particle formation resulting from exhaust aging was generally important for all the buses (79% showed an average EFPM:AGED/EFPM:FRESH ratio >10) and fuel types tested, suggesting an important nonfuel dependent source. The results suggest that the potential for forming secondary mass should be considered in future fuel shifts, since the environmental impact is different when only considering the primary emissions.

  • 7.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Kong, Xiangrui
    Mark Salvador, Christian
    Carlsson, Staffan
    Pathak, Ravikant
    Davidsson, KentO
    Le Breton, Michael
    Mwaniki Gaia, Samuel
    Mitra, Kalyan
    Hallquist, Mattias
    B. C. Pettersson, Jan
    Factor Analysis and Molecular Characterization of Emissions from a Residential Wood Burning Boiler2019Article in journal (Refereed)
  • 8.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Le Breton, M.
    Psichoudaki, M.
    Watne, Å.K.
    Lutz, A.
    Hallquist, M.
    Application of a FIGAERO ToF CIMS for on-linecharacterization of real-world fresh and agedparticle emissions from buses2019In: Aerosol Science and Technology, ISSN 0278-6826, E-ISSN 1521-7388Article in journal (Refereed)
  • 9.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Le Breton, Michael
    Psichoudaki, Magda
    Hallquist, Mattias
    K. Watne, Ågot
    Lutz, Anna
    Application of a FIGAERO ToF CIMS for on-line characterization of real-world fresh and aged particle emissions from buses2019In: Aerosol Science and Technology, ISSN 0278-6826, E-ISSN 1521-7388Article in journal (Refereed)
  • 10.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Li, Jinjian
    Liu, Qianyun
    Li, Yongjie
    Liu, Tengyu
    Huang, Dandan
    Zheng, Jing
    Zhu, Wenfei
    Hu, Min
    Wu, Yusheng
    Lou, Shengrong
    Hallquist, Mattias
    K. Chan, Chak
    Canonaco, Franxesco
    S. H. Prévôt, André
    C. H. Fung, Jimmy
    K. H. Lau, Alexis
    Zhen Yu, Jian
    Characterization of Aerosol Aging Potentials at Suburban Sites in Northern and Southern China Utilizing a Potential Aerosol Mass (Go:PAM) Reactor and an Aerosol Mass Spectrometer.2019In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 214, no 10, p. 5629-5649Article in journal (Refereed)
  • 11.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    McFiggans, Gordon
    F. Mentel, Thomas
    Wildt, Jurgen
    Pullinen, Iida
    Kang, Sungah
    Kleist, Einhard
    Schmitt, Sebastian
    Springer, Monika
    Tillmann, Ralf
    Wu, Cheng
    Zhao, Defeng
    Hallquist, Mattias
    Faxon, Cameron
    Le Breton, Michael
    Simpson, David
    Bergstrom, Robert
    E. Jenkin, Michael
    Ehn, Mikael
    A. Thornton, Joel
    Rami Alfarra, M.
    J. Bannan, Thomas
    J. Percival, Carl
    Priestley, Michael
    Topping, David
    Kiendler-Scharr, Astrid
    Secondary organic aerosol reduced by mixture of atmospheric vapours2019In: Nature, ISSN 0028-0836, E-ISSN 1476-4687Article in journal (Refereed)
  • 12.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    McFiggans, Gordon
    F. Mentel, Thomas
    Wildt, Jürgen
    Pullinen, Lida
    Kang, Sungah
    Kleist, Einhard
    Schmitt, Sebastian
    Springer, Monika
    Tillmann, Ralf
    Wu, Cheng
    Zhao, Defeng
    Hallquist, Mattias
    Faxon, Cameron
    Le Breton, Michael
    Simpson, David
    Bergström, Robert
    E. Jenkin, Micheael
    Ehn, Mikael
    A. Thornton, Joel
    Rami Alfarra, M.
    J. Bannan, Thomas
    J. Percival, Carl
    Priestley, Michael
    Topping, David
    Kiendler-Scharr, Astrid
    Secondary organic aerosol reduced by mixture of atmospheric vapours2019In: Nature, ISSN 0028-0836, E-ISSN 1476-4687Article in journal (Refereed)
  • 13.
    Hallquist, Åsa
    et al.
    IVL Swedish Environmental Research Institute.
    Salberg, Håkan
    IVL Swedish Environmental Research Institute.
    Emissionsmätningar från bussar: Euroklass VI-gasbussar och bränsledrivna värmare i elbussar2022Report (Other academic)
    Abstract [en]

    Within the frame work of a research project funded by Västtrafik and the foundation SIVL, the emissions from individual Euro class VI gas buses and fuel-operated heaters in electric buses have been characterised, in total 37 buses (20 gas buses and 17 heaters).

    An extractive measurement method has been used where the ambient air is continuously measured, and particle and gaseous concentrations are measured with high time resolution (≥1 Hz).

    Emission factors (EFs) were retrieved using the carbon balance method, assuming complete combustion and a specific fuel carbon content. The results are reported as mass or number of pollutants per kilo fuel burnt. 

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  • 14.
    Jerksjö, Martin
    et al.
    IVL Swedish Environmental Research Institute.
    Hallquist, Åsa
    IVL Swedish Environmental Research Institute.
    Measurements of bus emissions 2010-20152016Report (Other academic)
    Abstract [en]

    In this report results from measurements of exhaust emissions from buses conducted by IVL between 2010 and 2015 are presented. The measurements are parts of three different studies of which the latest was conducted between 2014 and 2015. The measured emissions from all studies form a relatively large data set, which may be used for various analyses. This is the reason why IVL has chosen to present results from all three studies in this report, even if the focus lies on the latest study. The main objectives of the latest study were to: • measure emissions from Euro VI buses. • measure both NO (nitrogen oxide) and NO2 (nitrogen dioxide) and not only NO which was the case in the previous studies. • measure emissions from buses driving in real world traffic and not only during controlled conditions as was the case in the previous studies.

    In this report emissions of nitrogen oxides (NOX), carbon monoxide (CO) and particle mass (PM) are presented. The emissions have been analysed with respect to Euro class, exhaust aftertreatment and fuel type. The most important findings were: • The average emissions of NOX and particles from the tested Euro VI buses are significantly lower than from the tested Euro V buses. • The median particle emission from Euro V buses driving on 100% RME (Rapeseed Methyl Esther) was 88% lower compared to buses driving on (low blended) diesel. This result is based on measurements of buses from only one manufacturer. • The median nitrogen oxide emission from Euro V buses driving on 100% RME was 35% higher compared to buses driving on (low blended) diesel. This result is based on measurements on buses from only one manufacturer. However, the difference of the average values was not statistically significant. • No decrease in NOX emissions was observed going from Euro III to Euro V. • A constant decrease of particle emissions (by mass) was observed going from Euro III to Euro VI, with the exception of Euro IV buses using EGR. • Measured average NO2 share of NOX is in relatively good accordance with data from the road vehicle emission model HBEFA. However, the results indicate that the ratio is not only dependent on the Euro standard and the exhaust aftertreatment system but also on vehicle manufacturer. • Three out of the six buses which were tested fuelled with both (low blended) diesel and 100% RME did show a reduction of particle emissions when fuelled with RME. The remaining three buses showed an increase in PM emissions and a simultaneous increase in CO emissions.

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  • 15.
    Jerksjö, Martin
    et al.
    IVL Swedish Environmental Research Institute.
    Hallquist, Åsa
    IVL Swedish Environmental Research Institute.
    Fallgren, Henrik
    IVL Swedish Environmental Research Institute.
    Wängberg, Ingvar
    IVL Swedish Environmental Research Institute.
    Westerlund, Jonathan
    Avgasmätningar på bussar i verklig drift för identifiering av högemitterare2013Report (Other academic)
    Abstract [en]

    Inom ramen för ett forskningsprojekt samfinansierat av Västtrafik och Stiftelsen IVL har IVL under 2011 och 2012 genomfört avgasmätningar på ett hundratal bussar i Västsverige. Avgasmätningarna utfördes utomhus på gårdsplanerna hos de bussoperatörer där bussarna testats. Avgaserna mättes från varje buss när de vid upprepade tillfällen passerade mätutrustningen under fullgas¬acceleration. För att inte behöva ta hänsyn till utspädningen med luften mättes alla utsläpp relativt CO2 eftersom förhållandet till CO2 förblir konstant oberoende av utspädningen. Resultaten rapporteras som föroreningarnas massa per kilo förbrukat bränsle.

    I syfte att validera de vägkantsbaserade utsläppsmätningarna utfördes även inom projektet ombordmätningar på en buss (Euro V) med PEMS (Portable Emission Monitoring System). PEMS-mätningarna syftade även till att undersöka hur de uppmätta utsläppen under acceleration relaterar till utsläppen under körning i linjetrafik med en blandning av körning i stads- och landsbygdstrafik. Utifrån ombordmätningarna har för partiklar kunnat uppskattas gränsvärden på utsläpp under fullgasacceleration, vilka kan användas som indikation på att bussar vars utsläpp överskrider detta värde inte uppfyller de lagkrav de är certifierade mot. Bland annat till följd av den stora inverkan avgastemperaturen har på NOX-reningen hos Euro IV och Euro V bussar med SCR-katalysator, har motsvarande gränsvärden inte kunnat uppskattas för utsläpp av kväveoxider.

    Då bussar med olika drivmedel ingått i mätningarna har även drivmedlets inverkan på utsläppen kunnat studeras. Detta har dock främst varit möjligt för utsläpp av partiklar. När det gäller utsläpp av kväveoxider har det i de flesta fall inte gått att bedöma i vilken grad variationer i utsläpp berott på vilket bränsle som använts eller på otillräcklig reningsfunktion hos SCR-systemet till följd av för låg avgastemperatur.

    Om den vägkantsbaserade avgasmätmetoden ska kunna användas för att bedöma utsläpps-prestanda med avseende på kväveoxider i relation till gällande avgaskrav för bussar som är certifierade att klara Euro IV och Euro V kraven och som har SCR-katalysator, måste man försäkra sig om att avgastemperaturen vid mättillfället är tillräckligt hög för att SCR-systemet ska fungera optimalt. Detta är möjligt att uppnå om mätplatsen väljs så att mätningarna kan utföras i direkt anslutning till att bussen kommit från körning på landsväg eller motorväg.

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    FULLTEXT01
  • 16.
    Munthe, John
    et al.
    IVL Swedish Environmental Research Institute.
    Hallquist, Åsa
    IVL Swedish Environmental Research Institute.
    Moldanova, Jana
    IVL Swedish Environmental Research Institute.
    Photochemical Smog in China: Scientific challenges and implications for air quality policies2016In: National Science Review, ISSN 2095-5138Article in journal (Refereed)
    Abstract [en]

    Severe air pollution events in many parts of China pose a major threat to health and ecosystems. China's air pollution is concentrated to economically developed areas, for instance Beijing-Tianjin-Hebei (BTH) and Pearl-River-Delta (PRD). The situation has received considerable attention in international and national media including its secondary societal and economic impacts such as lowered productivity, reduced investments and loss of professionals who have the choice of residing elsewhere.

    Large efforts are today underway from the Government to improve the situation by measures to reduce primary emissions, see Airborne Pollution Prevention and Control Action Plan (2013-2017), available at http://www.gov.cn. This will also affect secondary pollutants such as ozone (O3) and particulate matter (PM) but how and to what magnitude is uncertain. The photochemically induced secondary pollutants will add to any severe local urban air pollution but requires a very different approach for abatements. In this perspective view we will address the complexity of photochemical smog while acknowledging the urge for similar descriptions on local urban air pollution as described elsewher.

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