Characterization of Fine Particle and Gaseous Emissions during School Bus Idling

The particulate matter (PM) and gaseous emissions from six diesel school buses were determined over a simulated waiting period typical of schools in the northeastern U.S. Testing was conducted for both continuous idle and hot restart conditions using a suite of on-line particle and gas analyzers installed in the U.S. Environmental Protection Agency's Diesel Emissions Aerosol Laboratory. The specific pollutants measured encompassed total PM-2.5 mass (PM 2.5 m in aerodynamic diameter), PM-2.5 number concentration, particle size distribution, particle-surface polycyclic aromatic hydrocarbons (PAHs), and a tracer gas (1,1,1,2,3,3,3-heptafluoropropane) in the diluted sample stream. Carbon monoxide (CO), carbon dioxide, nitrogen oxides (NOx), total hydrocarbons (THC), oxygen, formaldehyde, and the tracer gas were also measured in the raw exhaust. Results of the study showed little difference in the measured emissions between a 10 min post-restart idle and a 10 min continuous idle with the exception of THC and formaldehyde. However, an emissions pulse was observed during engine restart. A predictive equation was developed from the experimental data, which allows a comparison between continuous idle and hot restart for NOx, CO, PM-2.5, and PAHs and which considers factors such as the restart emissions pulse and periods when the engine is not running. This equation indicates that restart is the preferred operating scenario as long as there is no extended idling after the engine is restarted. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/0013936X
• Authors:
  • KINSEY, J S
  • WILLIAMS, D C
  • DONG, Y
  • LOGAN, R
• Publication Date: 2007-7-15

Language

• English

Media Info

• Pagination: 4972-4979
• Serial:
  • Environmental Science & Technology
  • Volume: 41
  • Issue Number: 14
  • Publisher: American Chemical Society
  • ISSN: 0013-936X
  • EISSN: 1520-5851
  • Serial URL: http://pubs.acs.org/journal/esthag

Subject/Index Terms

• TRT Terms: Buses; Diesel engines; Environment; Measurement; Pollutants; Schools; Simulation
• Geographic Terms: United States
• ITRD Terms: 1272: Bus; 1314: Diesel engine; 2442: Emission; 2455: Environment; 6136: Measurement; 101: School; 9103: Simulation; 8122: USA
• Subject Areas: Education and Training; Energy; Environment; Public Transportation; I15: Environment;

Filing Info

• Accession Number: 01076228
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Sep 18 2007 10:16AM