Ozone pollution control strategies examined by Empirical Kinetics Modeling Approach over the Beaumont-Port Arthur region in Texas of USA

Abstract

Ground-level ozone is harmful to both human health and ecological environment, which is formed by reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. With the increasingly rigorous ozone standard in the U.S., it is important to examine ozone pollution control strategies to help air-quality management in a concentrated industrial region, such as Beaumont-Port Arthur (BPA) areas in Texas of USA. In this study, the method of Empirical Kinetics Modeling Approach (EKMA) associated with the comprehensive air quality modeling with extensions (CAMx) have been employed to demonstrate feasible air-quality control strategies to examine the effects of VOCs and NOx abatement on ozone concentration in the BPA area. Case studies included base case simulations as well as those with 25%, 50%, and 75% reductions of anthropogenic NOx and/or VOCs emissions in the BPA area, which were based on the TCEQ-provided meteorological and emission inventories for a high ozone episode. Simulation results indicated that NOx abatement is more effective than VOCs abatement in reducing ozone concentrations for BPA area, which suggestively belongs to the NOx-sensitive regime for ozone pollution. The average 8-hr ozone could be reduced 3.3%, 7.0% and 11.1%, respectively, by 25%, 50% and 75% of both NOx and VOCs emission abatement. The effect of pollutant abatement on ozone reduction is observed to be different at eight monitor stations in BPA region. Also, the nonlinear relationship between ozone and its precursors has been observed. This study could be helpful to provide scientific and technological support for the future development of air-quality management and ozone control strategies in a concentrated industrial region.