多环芳烃在风积沙土壤中的光降解研究

The photodegradation of phenanthrene on aeolian sand under sunlight

多环芳烃(PAHs)是一类难降解的持久性有机污染物,其因分布广泛并具有致畸、致癌、致突变的特性而受到国内外学者的广泛关注。文中以多环芳烃菲(Phe)为目标污染物,用卤钨灯模拟太阳光,研究了在风积沙土壤中,p H值、污染物初始浓度及光照强度对光降解PAHs的影响。结果表明:在125W的光强下光解1.5h,不同p H值3.0、5.0、7.0、9.0和11.0的光降解率分别为43.05%、47.48%、50.16%、58.13%、60.47%;初始浓度分别为500、750、1000、1250、1500mg/L的光降解率分别为64.28%、59.87%、55.79%、52.67%、49.03%;在同一光照强度下,时间越久,PAHs的光解程度越高;不同光照强度55、75、100、125W时,Phe的半衰期分别为0.46、0.44、0.29、0.25h。该研究对光降解土壤中多环芳烃有机污染物有重要的现实意义。

Polycyclic aromatic hydrocarbons（ PAHs） are a group of persistent organic pollutants that are ubiquitous in environment due to their toxicity,mutagenicity and carcinogenicity. We studied the aeolian sand PAHs photodegradation under sunlight irradiation simulated by tungsten halogen lamp with phenanthrene（ Phe） as target contaminant. The effects of p H,initial concentration and illumination intensity on the Phe photodegradation were investigated. The results show that the photodegradation rates of Phe in different p H 3. 0,5. 0,7. 0,9. 0 and11. 0 under strong light 125 W in 1. 5 h were 43. 05%,47. 48%,50. 16%,58. 13%,60. 47%,respectively. The rates of photodegradation of Phe were 64. 28%,59. 87%,55. 79%,52. 67% and 49. 03%,respectively with initial concentration of Phe 500,750,1000,1250 and 1500 mg / L respectively. And the photodegradation rate of PAHs increased with increasing of illumination time and intensity. When illumination intensity were 55,75,100 and 125W,half- times of Phe were 0. 46,0. 44,0. 29 and 0. 25 h. The study would provide important practical significance for further studies on improvement of photodegradation of PAHs on soil.