摘要: |
This final report presents the investigation results of the CARB vehicle emissions study, with focus on the physicochemical and toxicological properties of the semi-volatile and non-volatile fractions of PM from heavy duty diesel vehicles, operating with and without emissions control technologies. A wide variety of diesel fuelled vehicles, representing the current in-use fleet, have been tested in the California Air Resources Boards (CARB) heavy-duty diesel emission testing laboratory (HDETL) in downtown Los Angeles, including a 1998 Kenworth truck, a diesel hybrid electric bus, a school bus, and a Caltrans truck on three driving cycles, i.e. steady state cruise (50mph), transient (EPA urban dynamometer driving schedule (UDDS)) and idle to simulate various real-world driving conditions. The tested emission control devices include a Continuously Regenerating Technology (CRT); CRT in combination with a selective catalytic reduction system (Zeolite or vanadium based SCRTs) etc. Detailed physicochemical and toxicological characteristics of PM were measured for each vehicle and driving cycle, including physical properties (e.g. PM mass and size distribution), chemical (EC, OC, organic compounds, trace elements, inorganic ions) and toxicological (dithiothreitol (DTT) and macrophage reactive oxygen species (ROS)assays) characterization of the collected PM samples. |