Impact of emissions from a single urban source on air quality estimated from mobile observation and WRF-STILT model simulations

For industrial cities, quantifying the influence of a given emission source on air quality is very important for making a detailed control strategy to the emissions. By taking use of the mobile observations and WRF-STILT model simulations, this study analyzes the air pollution characteristics and air quality influences from an industrial emission source in Xinji, China. During the study period, the hourly average concentrations of smoke, SO2, and NOx emitted from the industrial source are 1.01, 22.04, and 26.22 mg/m3, respectively. The mobile observations show that with the increase of distance from the emission source, the concentration of air pollutants increases first and then decreases. The peak values of PM2.5, SO2, and NOx appear at the distance of around 0–3 km away from the emission source, among which PM2.5 and SO2 increase first and then decrease before stabilizing, while NOx is interfered by emissions from the traffic along the roads. Within the distance of 3 km, the emission source has obvious influence on the air quality with contribution rate 10–48% at night time and 3–23% at day time. The simulation results of WRF-STILT also support the observed gradient change characteristics of air pollutants, suggesting that this industrial emission source is an important pollution source for regions around it. Our results further show that the meteorological conditions play an important role on the transport capacity of industrial emissions. The results of this study provide support for quantifying the scope of influence of fixed emission sources, especially in industrial cities.