School of Environmental Science, Liaoning University, Shenyang 110036, China.
J Hazard Mater. 2010 Jan 15;173(1-3):168-72. doi: 10.1016/j.jhazmat.2009.08.059. Epub 2009 Aug 22.
The rates of photodegradation of pyrene (Pyr) on soil surfaces under UV light have been studied. Different parameters such as temperature, soil particle sizes, soil depth, and humic acid (HA) concentration responsible for photodegradation have been monitored. The results obtained indicated that Pyr photodegradation follows pseudo-first-order kinetics. Pyr degradation was fastest at 30 degrees C, while the photodegradation rate was increased with the temperature from 20 to 30 degrees C. The degradation loss was about 35% at 30 degrees C, 30% at 25 degrees C and 25% at 20 degrees C, respectively. The rates of Pyr photodegradation at different soil particle sizes followed the order: less than 1mm>less than 0.45 mm>less than 0.25 mm. The results showed that the relationship of Pyr half-life with soil depth was linear (significant correlation, p<0.01). When the soil depth increased from 1 to 4mm, the half-life increased from 19.80 to 37.46 d. HA treatments significantly increased the photodegradation of Pyr on soil surfaces under UV light. However the concentration of HA increased from 5 to 40 mg kg(-1), the pseudo-first-order rates of Pyr decreased due to the shielding effect of HA.
已研究了蒽（Pyr）在紫外光下于土壤表面的光降解速率。监测了负责光降解的不同参数，如温度、土壤粒径、土壤深度和腐殖酸（HA）浓度。结果表明，Pyr 光降解遵循准一级动力学。30°C 时 Pyr 降解最快，而光降解速率随温度从 20°C 增加到 30°C 而增加。在 30°C 时，降解损失约为 35%，在 25°C 时为 30%，在 20°C 时为 25%。不同土壤粒径的 Pyr 光降解速率依次为：小于 1mm>小于 0.45mm>小于 0.25mm。结果表明，Pyr 半衰期与土壤深度呈线性关系（显著相关，p<0.01）。当土壤深度从 1mm 增加到 4mm 时，半衰期从 19.80d 增加到 37.46d。HA 处理显著增加了 Pyr 在紫外光下于土壤表面的光降解。然而，当 HA 浓度从 5mgkg(-1)增加到 40mgkg(-1)时，由于 HA 的屏蔽效应，Pyr 的准一级速率降低。
