气相过氧化氢的生成及大气中浓度的测定

Formation of Hydrogen Peroxide in Gaseous Phase and the Determination of Its Atmospheric Concentrations

研究了ＨＣ－ＮＯ２－空气体系中Ｈ２Ｏ２和有机氢过氧化物的生成。模拟实验结果表明：Ｈ２Ｏ２生成浓度的最大值与碳氢化合物的初始浓度成正比；生成规律与Ｏ３生成规律类似，比值［Ｏ３］ｍａｘ／［Ｈ２Ｏ２］ｍａｘ随［ＨＣ］０增大而减小。在乙烯、戊烷体系中，Ｈ２Ｏ２在总过氧氢化物的比例为０．６左右；而丙烯体系中，随光照时间的延长，有较多的有机氢过氧化物产生。大气监测结果显示：Ｈ２Ｏ２的生成受污染物排放、日照及温度的影响，早晚浓度低，午后形成峰值，日变化规律与Ｏ３浓度变化相似，监测到的最大浓度值在春季为１．３×１０－９，在秋节为０．６４×１０－９。

Studies on the formations of H2O2 and organic hydrogen Peroxides in the HC-NO2-dry air systems were carried out in an indoor smog chamber. The results from simulated experiments show that the maximum concentrations of H2O2 formed are directly proPOrtional to the initial concentrations of hydrocarbons (HC)0;H2O2 is formed by following a similar rule to that of ozone (O3),and the ratio of (O3)max/ (H2O2 )max decreases with increasing (HC)0. In the system of ethylene or pentune, the ratio of H2O2 to total hydroperoxides (THP) is about 0. 6; and in the system of propylene, more orgsnic hydrogen peroxides are formed with extending irradiation time. The resultS from atmospheric monitoring show that the formation of H2O2 is dependent on emission of pollutants, sunshine and temperature, and it has a lower concentration in both morning and evening and a ark concentration occurred after noon, following a daily change pattern similar to that of ozone. The atmospheric H2O2 was found to have a maximum concentration of 1.3×10-9 in spring and of 0.64×10-9 in autumn as monitored in Beijing in 1991.