Rapid identification of high particle number emitting on-road vehicles and its application to a large fleet of diesel buses

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • E. R. Jayaratne
  • L. Morawska
  • Z. D. Ristovski
  • C. He

Detail(s)

Original languageEnglish
Pages (from-to)5022-5027
Journal / PublicationEnvironmental Science and Technology
Volume41
Issue number14
Publication statusPublished - 15 Jul 2007
Externally publishedYes

Abstract

Pollutant concentrations measured in the exhaust plume of a vehicle may be related to the pollutant emission factor using the CO2 concentration as a measure of the dilution factor. We have used this method for the rapid identification of high particle number (PN) emitting on-road vehicles. The method was validated for PN using a medium-duty vehicle and successfully applied to measurements of PN emissions from a large fleet of on-road diesel buses. The ratio of PN concentration to CO2 concentration, Z, in the exhaust plume was estimated for individual buses. On the average, a bus emitted about 1.5 × 109 particles per mg of CO2 emitted. A histogram of the number of buses as a function of Z showed, for the first time, that the PN emissions from diesel buses followed a gamma distribution, with most of the values within a narrow range and a few buses exhibiting relatively large values. It was estimated that roughly 10% and 50% of the PN emissions came from just 2% and 25% of the buses, respectively. A regression analysis showed that there was a positive correlation between Z and age of buses, with the slope of the best line being significantly different from zero. The mean Z value for the pre-Euro buses was significantly greater than each of the values for the Euro I and II buses. © 2007 American Chemical Society.

Citation Format(s)

Rapid identification of high particle number emitting on-road vehicles and its application to a large fleet of diesel buses. / Jayaratne, E. R.; Morawska, L.; Ristovski, Z. D.; He, C.

In: Environmental Science and Technology, Vol. 41, No. 14, 15.07.2007, p. 5022-5027.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review