Evaluating ozone production intensity and BTEXS-NOx reduction scenarios in the yeosu petrochemical industrial atmosphere.

Understanding O3 formation in petrochemical regions requires consideration of how abundant precursor emissions influence local photochemical characteristics. This study investigated ozone production characteristics at the Yeosu National Petrochemical Industrial Complex. We observed gaseous pollutants and Benzene, Toluene, Ethylbenzene, Xylene, Styrene (BTEXS) concentrations, calculated radical-based ozone production rates p(O3), and performed Framework for 0-D Atmospheric Modeling (F0AM) simulations. During the observation period, mean O3, NO, NO2, and CO concentrations were 54.32 ± 19.88, 2.99 ± 3.56, 17.42 ± 11.34, and 152.86 ± 90.78 ppb, respectively. Among BTEXS compounds, toluene showed the highest mean concentration, followed by benzene, m&p-xylene, ethylbenzene, styrene, and o-xylene. O3 exhibited clear daytime enhancement, while BTEXS compounds showed compound-specific temporal and diurnal patterns associated with industrial emissions and photochemical reactivity. Calculated p(O3) was positively associated with both observed and F0AM-simulated O3, with the stronger relationship for F0AM providing an internal consistency check between the simplified calculation and box-model results. Precursor reduction scenarios showed that simultaneous NOx and BTEXS reductions decreased p(O3). These results highlight the importance of coordinated control of NOx and reactive aromatic volatile organic compounds (VOCs) for mitigating industrial ozone formation.Implications: This study provides a monitoring- and modeling-based assessment of ozone production in a petrochemical industrial atmosphere, where aromatic VOCs and NOx jointly influence photochemical ozone formation. By combining observed BTEXS and gaseous pollutant data with radical-based p(O3) calculations and F0AM simulations, the results identify high-production conditions under which precursor reductions are most effective. The findings suggest that coordinated control of NOx and reactive aromatic VOCs, rather than single-precursor management, is necessary to reduce ozone formation in petrochemical industrial regions. This approach can support targeted emission-control strategies for industrial air-quality management.