Ozone ( O ₃ ) ambient levels as a secondary airborne precursor in Fahaheel urban area, the State of Kuwait

摘要

Two years of continuous monitoring data over two time‐spans (2004–2005 and 2014–2015) were used to investigate the relationship between ozone (O_(3)) and nitrogen oxides (NO_(X)?≈?NO?+?NO_(2)) in Fahaheel urban area (Kuwait). Their relationship was used to understand their chemical reactions and the NO_(2)and O_(3)concentration ratio to gain an insight into the sources of total atmospheric oxides (O_(X)= O_(3)?+?NO_(2)) levels. A Chemical Mass Balance (CMB) model was developed to detect likely point sources around the monitoring station and quantify their contribution to the overall air pollution load. Hourly diurnal variations in O_(3)ground level concentrations during weekends showed a slight increase in O_(3)levels. In addition, it was observed that overall hourly average O_(3)concentration reached higher levels during weekdays and weekends in 2004–2005 compared to 2014–2015. The concentration of photochemical oxidants (e.g., O_(3)and NO_(2)) can be decreased by controlling the emissions of their precursors; NO_(X)and VOCs. The net effect of NO_(X)emissions on O_(3)concentrations was negative with a weak exponential decline correlation between NO_(X)and O_(3), indicating Fahaheel urban area's VOC‐sensitive characteristics. For all years considered, the slopes of the linear O_(X)–NO_(X)relationships were higher during daytime compared to night‐time, showing that NO_(2)oxidations were dominant during daytime and that O_(3)net production was high. The study also showed the high NO_(X)oxidation level and the possible presence of O_(3)net production. The slopes during night‐time indicated that NO_(2)consumption exceeded its formation rate. During day and night‐time, the NO_(2)/NO_(X)ratio was found to decline significantly as newly emitted NO_(X)increased, supporting the area's VOC‐sensitive nature. By setting up a CMB model around the Fahaheel receptor point, it was revealed that downstream petroleum facilities have been the major contributor to pollutants environmental load over the years. Two years of continuous monitoring data over two time spans (2004–2005 and 2014–2015) were used to investigate the relationship between ozone (O_(3)) and nitrogen oxides (NO_(X)?≈?NO?+?NO_(2)) in Fahaheel urban area (Kuwait). Their relationship was used to understand their chemical reactions; and the NO_(2)and O_(3)concentration ratio to gain an insight into the sources of total atmospheric oxides (O_(X)= O_(3)?+?NO_(2)) levels.