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Exhaust emissions of 23 individual city buses measured in Finland

Exhaust emissions of 23 individual city buses measured in Finland

Exhaust emissions of 23 individual city buses at EURO III, EURO IV and EEV (Enhanced Environmentally Friendly Vehicle) emission levels were measured in Helsinki, Finland.

Investigated buses represented different technologies in terms of engines, exhaust after-treatment systems (e.g., diesel particulate filter, selective catalytic reduction, and three-way catalyst) and fuels (diesel, diesel-electric (hybrid), ethanol, and compressed natural gas (CNG)). Emission from the buses were measured by the chasing method under real-world conditions at a depot area and on the normal route of bus line 24. The highest particulate emissions were detected from the EURO III and EURO IV buses and the lowest from the ethanol and CNG-fueled buses. The bus line experiments showed, however, that large variation existed between individual buses of the same type indicating that the operating conditions by drivers had large effect on the emissions. The detailed chemical composition of exhaust particles was determined by using a soot particle aerosol mass spectrometer (SP-AMS). Based on the SP-AMS results, the bus emission particles were dominated by organics and refractory black carbon (rBC). In addition to organics and rBC, the presence of trace metals in the bus emission particles was investigated.

More information:

Sanna Saarikoski, tel. +358 50 590 6091, sanna.saarikoski@fmi.fi

 

Liisa Pirjola, tel. +358 40 731 8045, liisa.pirjola@metropolia.fi

 

Saarikoski, S., Timonen, H. Carbone, S., Kuuluvainen, H.,  Niemi, J. V., Kousa, A., Rönkkö, T., Worsnop, D., Hillamo, R. & Pirjola, L.: Investigating the chemical species in submicron particles emitted by city buses, Aerosol Sci. Technol. 51, 317−329, 2017.

http://www.tandfonline.com/doi/pdf/10.1080/02786826.2016.1261992

Pirjola, L., Dittrich, A., Niemi, J. V., Saarikoski, S., Timonen, H., Kuuluvainen, H., Järvinen, A., Kousa, A., Rönkkö, T. & Hillamo, R.: Physical and chemical characterization of real-world particle number and mass emissions from city buses in Finland. Environ. Sci. Technol. 50, 294−304, 2016.

Sanna Saarikoski, puh. 050 590 6091, sanna.saarikoski@fmi.fi

 

Liisa Pirjola, puh. 040 731 8045, liisa.pirjola@metropolia.fi

 

Saarikoski, S., Timonen, H. Carbone, S., Kuuluvainen, H.,  Niemi, J. V., Kousa, A., Rönkkö, T., Worsnop, D., Hillamo, R. & Pirjola, L.: Investigating the chemical species in submicron particles emitted by city buses, Aerosol Sci. Technol. 51, 317−329, 2017.

http://www.tandfonline.com/doi/pdf/10.1080/02786826.2016.1261992

Pirjola, L., Dittrich, A., Niemi, J. V., Saarikoski, S., Timonen, H., Kuuluvainen, H., Järvinen, A., Kousa, A., Rönkkö, T. & Hillamo, R.: Physical and chemical characterization of real-world particle number and mass emissions from city buses in Finland. Environ. Sci. Technol. 50, 294−304, 2016.

http://pubs.acs.org/doi/pdf/10.1021/acs.est.5b04105


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