Characterization of Particle Bound Organic Carbon from Diesel Vehicles Equipped with Advanced Emission Control Technologies
- 18 February 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 43 (13), 4679-4686
- https://doi.org/10.1021/es8030825
Abstract
A chassis dynamometer study was carried out by the University of Southern California in collaboration with the Air Resources Board (CARB) to investigate the physical, chemical, and toxicological characteristics of diesel emissions of particulate matter (PM) from heavy-duty vehicles. These heavy-duty diesel vehicles (HDDV) were equipped with advanced emission control technologies, designed to meet CARB retrofit regulations. A HDDV without any emission control devices was used as the baseline vehicle. Three advanced emission control technologies; continuously regenerating technology (CRT), zeolite- and vanadium-based selective catalytic reduction technologies (Z-SCRT and V-SCRT), were tested under transient (UDDS) (1) and cruise (80 kmph) driving cycles to simulate real-world driving conditions. This paper focuses on the characterization of the particle bound organic species from the vehicle exhaust. Physical and chemical properties of PM emissions have been reported by Biswas et al. (Atmos. Environ.2008, 42, 5622-5634) and Hu et al. (Atmos. Environ.2008, submitted) Significant reductions in the emission factors (μg/mile) of particle bound organic compounds were observed in HDDV equipped with advanced emission control technologies. V-SCRT and Z-SCRT effectively reduced PAHs, hopanes and steranes, n-alkanes and acids by more than 99%, and often to levels below detection limits for both cruise and UDDS cycles. The CRT technology also showed similar reductions with SCRT for medium and high molecular weight PAHs, acids, but with slightly lower removal efficiencies for other organic compounds. Ratios of particle bound organics-to-OC mass (μg/g) from the baseline exhaust were compared with their respective ratios in diesel fuel and lubricating oil, which revealed that hopanes and steranes originate from lubricating oil, whereas PAHs can either form during the combustion process or originate from diesel fuel itself. With the introduction of emission control technologies, the particle bound organics-to-OC ratios (μg/g) decreased considerably for PAHs, while the reduction was insignificant for hopanes and steranes, implying that fuel and lubricating oil have substantially different contributions to the total OC emitted by vehicles operating with after-treatment control devices compared to the baseline vehicle since these control technologies had a much larger impact on PAH OC than hopanes and steranes OC.Keywords
This publication has 26 references indexed in Scilit:
- Real-time characterization of particle-bound polycyclic aromatic hydrocarbons in ambient aerosols and from motor-vehicle exhaustAtmospheric Chemistry and Physics, 2008
- Size Distribution of Trace Organic Species Emitted From Heavy-Duty Diesel VehiclesEnvironmental Science & Technology, 2007
- Evaluation of elemental carbon as a marker for diesel particulate matterJournal of Exposure Science & Environmental Epidemiology, 2003
- Particle number size distributions in a street canyon and their transformation into the urban-air background: measurements and a simple model studyAtmospheric Environment, 2002
- Chemiions and nanoparticle formation in diesel engine exhaustGeophysical Research Letters, 2001
- The accumulation of polycyclic aromatic hydrocarbons in lubricating oil over time — a comparison of supercritical fluid and liquid–liquid extraction methodsEnvironmental Pollution, 2001
- Distinction of volatile and nonvolatile particles in exhaust of diesel engines with particulate trapsJournal of Aerosol Science, 1999
- Characterization of Polycyclic Aromatic Hydrocarbons in Motor Vehicle Fuels and Exhaust EmissionsEnvironmental Science & Technology, 1999
- Measurement of Emissions from Air Pollution Sources. 2. C1 through C30 Organic Compounds from Medium Duty Diesel TrucksEnvironmental Science & Technology, 1999
- On-Road Emissions of Particulate Polycyclic Aromatic Hydrocarbons and Black Carbon from Gasoline and Diesel VehiclesEnvironmental Science & Technology, 1998