Characteristics of volatile organic emissions from Hong Kong traffics

Abstract

This research project studies the characteristics of volatile organic emissions from vehicular sources in Hong Kong. It covers the volatile organic emissions from vehicular sources, fuel evaporation and characteristics of volatile organic compound (VOC) in tunnels and ambient atmosphere. Through this research project, a better understanding of the impact of VOC to the air pollution problem in Hong Kong can be achieved. In the tunnel study, results demonstrate that alkenes and alkanes are the most abundant hydrocarbon groups in the selected tunnels. Also, these two groups of hydrocarbon are mainly from vehicle exhaust. Moreover, grab air samples were collected from different vehicular sources in Hong Kong to explore the emission characteristics of each vehicular source. The most abundant VOCs in the exhaust of diesel-powered vehicles and gasoline-powered vehicles are alkenes and aromatic hydrocarbons respectively. In the exhaust of LPG-powered vehicles, the most abundant VOCs are saturated hydrocarbons. For the ambient VOCs in Hong Kong, toluene contributions are high, which may due to gasoline evaporation from vehicles or solvent evaporation. In addition, 3 factors were extracted using the data collected by the multivariate statistical method of Principle Component Analysis (PCA). Results indicate that the VOCs in ambient air are highly influenced by gasoline evaporation, vehicle exhaust emissions and solvent evaporation.