Monitoring of PM-Bound Polycyclic Aromatic Hydrocarbons from Diesel Vehicles by Photoelectric Aerosol Sensor (PAS)

In addition to the required measurement of particulate matter (PM) mass emission, characterization (chemical composition, surface area, size and number distributions) of diesel PM is becoming increasingly important and may impact future PM emission regulations. This is especially the case for PM-bound polycyclic aromatic hydrocarbons (PAHs), an organic class that includes many potential mutagenic and carcinogenic species. In this study, we have evaluated a sensor technique, photoelectric aerosol sensor (PAS), for the possibility of continuous monitoring of PM-bound PAHs. Evaluation of PAS is performed with heavy duty diesel vehicles (trucks and buses) tested on a dynamometer with various transient driving schedules. Comparison study between PAS and standard chemical analysis of PAHs is also performed for a limited number of diesel and CNG buses. Validation of PAS has been carried out by analyzing the diesel particulate standard reference material SRM1650a with certified PAHs values from National Institute of Standards & Technology (NIST).