Two diesel buses respectively certified to meet China Ⅲ and China Ⅴ emission standards were used as prototype vehicles, fixed on a heavy-duty chassis dynamometer and driven according to a typical city bus driving cycle to analyze the pollutant emissions and volatile organic compounds (VOCs). The buses were fueled with diesel and waste cooking oil based biodiesel with 10 vol% blend ratio (B10). The emissions of total hydrocarbon(THC), CO, particulate matter (PM), and the number of solid particles with a diameter of 23 nm to 2.5 μm (referred to as "solid particulate number of PM2.5") from the bus certified to meet China Ⅴ (referred to as "China V bus") were 39.3%, 19.9%, 77.4%, and 28.4% lower than those from the other bus certified to meet China Ⅲ (referred to as "China Ⅲ bus"), while NOx emissions were 31.7% higher. Moreover, alkanes, alkenes, aromatic hydrocarbons, and oxygenated compounds in VOCs emitted from the China V bus were lower than those emitted from the China Ⅲ bus, suggesting lower atmospheric reactivity and smaller potential of secondary organic aerosol formation. Compared with the emission results of two diesel-fueled buses, the B10-fueled buses emitted smaller amounts of THC, CO, PM, and solid particulate number of PM2.5, lower oxygenated compounds but higher alkenes; slightly higher NOx emissions than China Ⅲ but slightly lower NOx emissions than China V. Consequently, the atmospheric reactivity of VOCs in exhaust gas from the bus fueled with B10 was higher than that from the diesel-powered bus.
Keywords: atmospheric reactivity; diesel bus; pollutant emission; volatile organic compounds; waste cooking oil based biodiesel.