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Emissions from passenger cars are one of major sources that deteriorate urban air quality. This study presents characterization of real-drive emissions from three Euro 6 emission level passenger cars (two gasoline and one diesel) in terms of fresh particles and secondary aerosol formation. The gasoline vehicles were also characterized by chassis dynamometer studies. In the real-drive study, the particle number emissions during regular driving were 1.1–12.7 times greater than observed in the laboratory tests (4.8 times greater on average), which may be caused by more effective nucleation process when diluted by real polluted and humid ambient air. However, the emission factors measured in laboratory were still much higher than the regulatory value of 6 × 1011 particles km−1. The higher emission factors measured here result probably from the fact that the regulatory limit considers only non-volatile particles larger than 23 nm, whereas here, all particles (also volatile) larger than 3 nm were measured. Secondary aerosol formation potential was the highest after a vehicle cold start when most of the secondary mass was organics. After the cold start, the relative contributions of ammonium, sulfate and nitrate increased. Using a novel approach to study secondary aerosol formation under real-drive conditions with the chase method resulted mostly in emission factors below detection limit, which was not in disagreement with the laboratory findings. publishedVersion

Exhaust emissions from traffic significantly affect urban air quality. In this study, in-traffic emissions of diesel-fueled city buses meeting enhanced environmentally friendly vehicle (EEV) and Euro VI emission limits and the effects of retrofitting of EEV buses were studied on-road by chasing the buses with a mobile laboratory in the Helsinki region, Finland. The average emission factors of particle number (PN), particle mass (PM

Particle chemical composition, physical properties and concentrations of selected gaseous compounds were measured on-board a large RoRo passenger ship equipped with an open loop scrubber and diesel oxidation catalyst. Measurements were made using on-line measuring devices with high time resolution together with filter based samplings. The aim of the measurements were to gather information on the performance of exhaust aftertreatment. Measurements showed that scrubber reduce effectively the SO2 concentration from the exhaust gas and also concentration of NOx was reduced. CO and hydrocarbon concentrations were reduced by diesel oxidant catalyst located before scrubber. Particulate matter (PM) consisted mainly sulphate, organics and black carbon (BC). During open sea cruising (65% engine load) the major particulate chemical compound measured after scrubber was sulphate (66%). However its concentration was very low (~40 mg/Sm3 dry). Markedly lower sulphate concentrations were measured at 17% engine load which is connected to lower engine temperature and reduced conversion of SO2 to SO3. About one third of measured PM was organic matter and only about 4% (

ln-depth measurements of gaseous and particulate emissions were conducted onboard an ocean vessel by researcheis from VTT Technical Research Centre'of Finland Ltd, Finnish Meteorological Institute and Tampere University of Technology. Altogether more than 20 different instruments were used in these onboard measurements. A variety of instruments, MAAP (Multi-angle absorption photometer), Aethalometer, FSN (Filter smoke number), AVL MSS (Micro Soot Sensor) were used to measure black carbon (BC) concentrations. In addition, in-depth characterization of gaseous emissions as well as particulate emissions (concentration, composition, size distribution) and their properties (e g. volatility, secondary aerosol formation potential) of a ship equipped with a modern after treatment system (catalyst + scrubber) was achieved by using state-of-the-art online measurement devices (e.9. SPAMS, ELPI, SMPS, PSM, CPC, FTIR, Horiba PG-250A, Pegasor PPS -sensor, Nephelometer, Thermodenuder, PAM -chamber) and filter collections (AVL Smart Sampler). Fuels during measurements were HFO (0.7Yo Sulphur) and MGO (.0.1% Sulphur). The aim of this measurement campaign was to 1) evaluate suitability of BC instruments for onboard measurements and 2) to conduct in-depth characterization of gaseous and particulate emissions of a modern low emission ship. A special focus was on BC emissions as the international maritime organisation (lMO) limit is anticipated for BC emitted by ships. Measurements were successful and large amount of data about the ship emissions was collected. The particulate and gaseous emissions of ship were very low, as expected for a modern ship. The goal is to publish results in the scientific journals and as conference publications. ln addition information for authorities and IMO about the suitability of BC measurement methods for onboard BC measurements will be provided.