Khoder M I
Air Pollution Department, National Research Centre, Dokki, Giza, Egypt.
Chemosphere. 2002 Nov;49(6):675-84. doi: 10.1016/s0045-6535(02)00391-0.
Sulfur dioxide, nitrogen dioxide, particulate sulfate and nitrate, gaseous nitric acid, ozone and meteorological parameters (temperature and relative humidity) were measured during the winter season (1999-2000) and summer season (2000) in an urban area (Dokki, Giza, Egypt). The average particulate nitrate concentrations were 6.20 and 9.80 microg m(-3), while the average gaseous nitric acid concentrations were 1.14 and 6.70 microg m(-3) in the winter and summer seasons, respectively. The average sulfate concentrations were 15.32 microg m(-3) during the winter and 25.10 microg m(-3) during the summer season. The highest average concentration ratio of gaseous nitric acid to total nitrate was found during the summer season. Particulate sulfate and nitrate and gaseous nitric acid concentrations were relatively higher in the daytime than those in the nighttime. Sulfur conversion ratio (Fs) and nitrogen conversion ratio (Fn) defined in the text were calculated from the field measurement data. Sulfur conversion ratio (Fs) and nitrogen conversion ratio (Fn) in the summer were about 2.22 and 2.97 times higher than those in the winter season, respectively. Moreover, sulfur conversion ratio (Fs) and nitrogen conversion ratio (Fn) were higher in the daytime than those in the nighttime during the both seasons. The sulfur conversion ratio (Fs) increases with increasing ozone concentration and relative humidity. This indicates that the droplet phase reactions and gas phase reactions are important for the oxidation of SO2 to sulfate. Moreover, the nitrogen conversion ratio (Fn) increases with increasing ozone concentration, and the gas phase reactions are important and predominant for the oxidation of NO2 to nitrate.
在埃及吉萨省多基市的一个市区，于冬季（1999 - 2000年）和夏季（2000年）对二氧化硫、二氧化氮、颗粒态硫酸盐和硝酸盐、气态硝酸、臭氧以及气象参数（温度和相对湿度）进行了测量。冬季颗粒态硝酸盐的平均浓度分别为6.20和9.80微克/立方米，而气态硝酸的平均浓度在冬季和夏季分别为1.14和6.70微克/立方米。硫酸盐的平均浓度在冬季为15.32微克/立方米，夏季为25.10微克/立方米。气态硝酸与总硝酸盐的平均浓度比值在夏季最高。颗粒态硫酸盐和硝酸盐以及气态硝酸的浓度在白天相对高于夜间。根据实地测量数据计算了文中定义的硫转化率（Fs）和氮转化率（Fn）。夏季的硫转化率（Fs）和氮转化率（Fn）分别比冬季高出约2.22倍和2.97倍。此外，在两个季节中，白天的硫转化率（Fs）和氮转化率（Fn）均高于夜间。硫转化率（Fs）随臭氧浓度和相对湿度的增加而升高。这表明液滴相反应和气相反应对于将SO2氧化为硫酸盐很重要。此外，氮转化率（Fn）随臭氧浓度的增加而升高，气相反应对于将NO2氧化为硝酸盐很重要且占主导地位。
