Characterization of Particulate Matter Emitted From Motor Vehicles: Integrated Measurements and Sample Particle ObservationsEPA Grant Number: U915236
Title: Characterization of Particulate Matter Emitted From Motor Vehicles: Integrated Measurements and Sample Particle Observations
Investigators: King, Brian R.
Institution: California Institute of Technology
EPA Project Officer: Lee, Sonja
Project Period: January 1, 1997 through January 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997) RFA Text | Recipients Lists
Research Category: Fellowship - Environmental Engineering , Academic Fellowships , Engineering and Environmental Chemistry
The objective of this research project is to characterize the particulate matter (PM) emitted from light-duty motor vehicles by integrating measurements of particle size distribution and chemical composition with chemical composition data taken at the single-particle level.
The dilution source sampler developed by Hildemann et al. (1989), which simulates the dilution process that occurs in an exhaust plume, has been modified to simultaneously collect fine PM, semi-volatile organic compounds, (SVOC), and volatile organic compounds, (VOC), and to measure the size distribution of the chemical composition of fine particulate emissions. Aerosol samples are collected using filter-based systems and cascade impactors for quantification of the emissions of trace metals, elemental and organic carbon, soluble ionic species, and individually speciated organic compounds. Particle size distributions are measured using a differential mobility analyzer and a laser optical particle counter. The size and chemical composition of individual particles also isare also measured using an aerosol time-of-flight mass spectrometer (ATOFMS). From these measurements, the size and composition distribution of the PM emissions from motor vehicles, as seen by conventional measurement methods, can be compared to the ATOFMS data. The ATOFMS then can then be calibrated in a way thatto allow quantification of the amount of the various chemical species in individual partcles. The strengths of these different measurement approaches can be combined in a way thatto creates a more complete picture of the motor vehicle emissions than is otherwise possible by the use of either filter-based samplers, impactors, electronic size distribution monitors, or the ATOFMS alone.