| A total of 30 light-, medium-, and heavy-duty vehicles from Guangzhou were tested over chassis dynamometers and vehicle exhaust gas samples were simultaneously collected for ammonia measurement using Nessler's Reagents spectrophotometry to calculate the ammonia emission factors. From the emission factors of the test vehicles, the total emissions of ammonia from motor vehicles in Guangzhou in 2009 were estimated based on the obtained ammonia emission factors. In addition, the relationship between emission factors of ammonia and that of CO and NOX was analyzed, and the impact of several key variables (such as vehicle type and emission standard) on emission rates of ammonia was examined and compared with other studies abroad. Based on the results of this study, the following conclusions were obtained:1. Emission factors of ammonia show large variations among vehicles of different categories. The mean emission factors of ammonia of light, medium, and large passenger cars were found to be 26.64 mg/km,41.97 mg/km,65.5 mg/km, and 107.18 mg/km, respectively.2. The average emissions of ammonia in Guangzhou in 2009 were estimated to be 983.26 t, with the maximum and minimum emissions amounting to 373.25t and 2135.96t, respectively. The light passenger cars were the primary emission sources, accounting for 53.7% of the total ammonia emissions, whereas the light trucks, medium and large passenger cars, medium- and heavy-duty trucks accounted for, respectively,11.5%,19%,15.8% of the total ammonia emissions.3. By analyzing the relationship of the emission factor of NH3 and that of CO, NOX, it was found that the emission rates of CO and NOX showed considerable correlations with that of NH3, with correlation coefficients of 0.352 and 0.499, respectively.4. It was found that vehicles with high ammonia emission rates showed the following characteristics:medium-and heavy-duty vehicles, vehicles with out-of-date emission standards, mid-range odometer readings, and higher CO and NOX emission rates.
|
PDF Full Text Request