TY - JOUR
AU1 - Chen, Hung-Hong
AU2 - Shen, Yun-Hwei
AU3 - Yang, Hsi-Hsien
AU4 - Lu, Jau-Huai
AU5 - Wang, Lin-Chi
AU6 - Hsieh, Yen-Kung
AU7 - Lee, Chia-Fon
AU8 - Lin, Sheng-Lun
AB - Scooter emissions have attracted attention in recent years because of human exposure to their direct effects in urban areas. Trace toxics, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) have thus become important in scooter emissions. In this work, ten Tier 5 and 6 scooters were tested using a 100-second model to analyze their PCDD/F and PCB emissions and compare the results with previous Tier 3 studies. Tier 5 and 6 scooters emitted 1.86–2.91 and 0.133–0.298 pg WHO-TEQ Nm−3 of PCDD/Fs and PCBs, respectively. It was interesting to find that the PCDD/Fs were reduced by 94.6–97.4% and 99.4–99.6% in Tier 5 and 6 motors, respectively. The congener profiles of PCDD/Fs were affected by improving the emission control. The domination of highly chlorinated congeners shown in Tier 3 was reduced in Tier 5 with increases in low chlorinated PCDFs. This showed that de novo synthesis occurred and could be inhibited by the OBD system in Tier 6. The tailpipe renews reduced 60.0–93.8% of PCDD/Fs and 85.3–97.7% of PCB emissions, but several cases would still exhibit a delay for stable operation of a catalytic converter. The annual emissions of PCDD/F TEQ was calculated based on the statistics in 2019 and tested as 1.63 g WHO-TEQ. It could be 99.7% reduced to 3.55 mg by replacing all scooters with Tier 6. Consequently, the improvement of electronic fuel injection and onboard diagnostics systems from a carburetor without feedback control not only reduced the regulated pollutants but effectively reduced PCDD/F emissions.
TI - Newer Generation of Scooters: Polychlorinated Dibenzo-p-dioxin and Dibenzofuran and Polychlorinated Biphenyl Reductions
JF - Aerosol and Air Quality Research
DO - 10.4209/aaqr.2020.04.0138
DA - 2020-06-01
UR - https://www.deepdyve.com/lp/springer-journals/newer-generation-of-scooters-polychlorinated-dibenzo-p-dioxin-and-chifXCC9UU
SP - 1495
EP - 1509
VL - 20
IS - 6
DP - DeepDyve
ER -