Environment Research Institute, Shandong University, Qingdao 266237, China.
Environment Research Institute, Shandong University, Qingdao 266237, China; Jiangsu Collaborative Innovation Center for Climate Change, Nanjing, Jiangsu 210093, China.
Sci Total Environ. 2020 Jul 20;727:138631. doi: 10.1016/j.scitotenv.2020.138631. Epub 2020 Apr 13.
Seventeen polycyclic aromatic hydrocarbons (PAHs) and eight nitrated PAHs (NPAHs) in PM and conventional gaseous pollutants exhausted from 54 in-use gasoline vehicles encompassing different emission standards (China 1 to China 5) were tested on the chassis and engine dynamometric test bench. With the increase of emission standards, a decrease in the emissions of PM-bound PAHs and NPAHs was detected. The emission factors (EFs) of total PAHs and NPAHs in PM emitted by the vehicles with a mileage of >100,000 km were greater than that emitted by the vehicles with driving mileage of <100,000 km under all the five emission standards. The EFs of PM-bound PAHs and NPAHs emitted from port fuel injection engines were larger than that from gasoline direct injection engines. The emissions of PM-bound PAHs and NPAHs were less correlated with the exhaust of CO, while the hydrocarbon (HC) emissions were strongly correlated with the PM-bound PAHs emissions. The emissions of NPAHs and NOx had an inverse correlation. The toxic (TEQs) of total PAHs and NPAHs in China 3, China 4 and China 5 were significantly reduced compared to China 1 and China 2, which may be related to exhaust technology improvements. Although the EFs of NPAHs were significantly lower than those of PAHs, the TEQs of NPAHs were higher, which indicates that the toxic effect of NPAHs emitted by gasoline vehicles were stronger than PAHs.
对 54 辆不同排放标准（中国 1 至中国 5）的在用汽油车在底盘和发动机测功机上排放的 PM 和常规气态污染物中的 17 种多环芳烃（PAHs）和 8 种硝化多环芳烃（NPAHs）进行了测试。随着排放标准的提高，检测到 PM 结合态 PAHs 和 NPAHs 的排放量减少。在所有 5 种排放标准下，行驶里程>100,000km 的车辆排放的 PM 结合态总 PAHs 和 NPAHs 的排放因子（EFs）大于行驶里程<100,000km 的车辆排放的 EFs。燃油喷射发动机排放的 PM 结合态 PAHs 和 NPAHs 的 EFs 大于直喷发动机。PM 结合态 PAHs 和 NPAHs 的排放与 CO 排放的相关性较小，而碳氢化合物（HC）排放与 PM 结合态 PAHs 的排放密切相关。NPAHs 和 NOx 的排放呈负相关。与中国 1 和中国 2 相比，中国 3、中国 4 和中国 5 中的总 PAHs 和 NPAHs 的毒性（TEQs）明显降低，这可能与排气技术的改进有关。尽管 NPAHs 的 EF 明显低于 PAHs，但 NPAHs 的 TEQs 更高，这表明汽油车排放的 NPAHs 的毒性作用比 PAHs 更强。
