| Autor: |
Zhang Z; School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063, China.; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., Qiao LP; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., Zhou M; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., Huang DD; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., An JY; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., Guo HQ; School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063, China.; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang 330063, China., Wang HL; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., Huang C; State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China., Dong ZX; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China., Wang SX; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China. |
| Abstrakt: |
Continuous on-line observation of particulate matter and PM 2.5 chemical composition was conducted from October 15 th to November 7 th 2019 in East China. During the observation period, a wide range of dust-related processes took place. According to supplementary urban air quality assessment affected by dust (hereafter referred to as supplementary provisions), the observations were divided into four stages including pre-dust event, dust Ⅰ, dust Ⅱ, and post-dust event. The dust Ⅰ stage represented the processes of transportation and retention, while the dust Ⅱ stage represented processes of backflow from the sea and scavenging. The start time of the studied dust event was October 29 th 08:00-09:00 based on the supplementary provisions, dust tracers, and air quality models; however, disagreements existed between these data sources with respect to the finishing time. The supplementary provisions could not effectively distinguish backflow dust from sea, and results from different dust tracers were variable. The WRF-CMAQ model simulated dust variation trends well but overestimated short-term suspended dust and backflow dust. PM 10 , PM 2.5 , and trace element concentrations were much higher during dust events than during non-dust periods, with highest daily concentrations of (234.8±125.5), (76.8±22.5), and (17.54±10.5) μg·m -3 , respectively, which occurred on October 29 th . During the dust event, concentration of crustal elements were remarkably high in PM 2.5 . At the same time, secondary ions (SO 4 2- , NO 3 - , and NH 4 + ) contributed less to PM 2.5 mass concentrations. Four major crustal elements (Al, Si, Ca, and Fe) accounted for 23.5% and 13.7% of the mass concentration of PM 2.5 and secondary ions accounted for 24.3% and 41.9% during dust Ⅰ and dust Ⅱ stages, respectively. Based on PMF source apportionment, Ca abundance, PM 2.5 /PM 10 in dust sources, and the reconstruction of crustal material, dust particulates accounted for 43.4%-50.0% of PM 2.5 and backflow dust accounted for 19.2%-24.7% of PM 2.5 . |
