煤烟粒子中PAH_S光化学降解的动力学

Photochemical degradation of PAH S on smoke particles in atmosphere

利用ＴＥＦＬＯＮ薄膜室内光化学烟雾箱研究了光强、湿度和温度对燃煤烟颗粒物上多环芳烃（ＰＡＨｓ）的光化学降解速率的影响。结果表明，ＰＡＨＳ光解速率常数随光强、湿度和温度的升高而增大。在冬季低光强和低水蒸汽浓度的条件下，ＰＡＨｓ降解速率很小，可在大气中停留数日，因而可传输较远距离。在夏季高光强和高水蒸汽浓度条件下，ＰＡＨｓ在数小时内即全部降解。通过对光强、水蒸汽浓度和温度的实验数据进行多元回归，得到了降解速率常数与各参数的函数式，即降解反应的动力学方程式。

The photochemical behavior of selected polycyelie aromatic hydrocarbons(PAH S),such as B(a)p,B(k)F and fluoranthene in coal smoke particles, was studied using an indoor Teflon smog chamber. Experiments suggest that the photochemical reaction of PAH S is of first order. The rates of PAH S were obtained .It shows that the reaction rate constant is proportional to light intensity and water vapor concentration.Temperature and PAH loading also influence PAH degrdation rate. A model for PAH loss has been developed on the basis of these results and its simulating results suggest that coal particle PAH half lives are of the order of a period of days in winter and a few hours in summer. Other factors which may have effect on the photochemical reaction of PAH have also been discussed.