[Ozone Pollution Control Strategies Based on VOCs Source Apportionment]

The frequent O₃ pollution in China occurs mainly in volatile organic compounds （VOCs） control areas. However， a simulation focusing on the influence of reduction from different VOCs sources is lacking. Thereby， we conducted online observations of 116 types of VOCs and HCHO based on liquid phase chemistry in the summer of 2024 in Nanjing. A positive matrix factorization （PMF） model was further combined with observational-based model （OBM） to explore O₃ control policies for emission reduction from different pollution sources. As a result， the maximum 8h moving average of O₃[ρ（MDA8-O₃）] in Nanjing exceeded the national standard （222 μg·m^-3）， and the average volume mixing ratio of total VOCs （including HCHO） was 30.2×10^-9， dominated by oxygenated VOCs and alkanes. Acetaldehyde， formaldehyde， and isoprene as the top three species contributed 51.8% of the total ozone formation potential （151 μg·m^-3）. Motor vehicle sources （33.9%） and industrial sources （26.4%） were the main sources of TVOCs. OBM simulation captured the measured O₃ （R=0.86） well， and the O₃ pollution in Nanjing was found to be in the VOCs control areas by the EKMA curve. The O₃ could reach the standard through a moderate reduction of VOCs （40%） or substantial reduction of NO_x （70%）. The scenario based on the observations and PMF resolved spectrum showed that O₃ pollution was more sensitive to motor vehicle sources and industrial sources， wherein reducing 90% of either source， respectively， could significantly reduce O₃ and reach the standard. This study on a basis of the measured pollutants could simulate the photochemical process in the real atmosphere to provide a theoretical suggestion for O₃ pollution control.