Sonochemical Degradation of Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoate (PFOA) in Landfill Groundwater: Environmental Matrix Effects
Sonochemical Degradation of Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoate (PFOA) in Landfill Groundwater: Environmental Matrix Effects
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DOI：
10.1021/es8013858
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发表时间：
2008-11-01
影响因子：
11.4
通讯作者：
Hoffmann, Michael R.
中科院分区：
文献类型：
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作者：
Cheng, Jie;Vecitis, Chad D.;Hoffmann, Michael R.
全氟化学品，如全氟辛烷磺酸（PFOS）和全氟辛酸（PFOA）具有环境持久性，对大多数传统化学和微生物处理技术具有抗性。在本文中，我们表明声溶能够分解存在于垃圾填埋场地下水中的全氟辛烷磺酸和全氟辛烷磺酸。然而，由于其他有机成分的存在，填埋场地下水中声化学I降解的伪一级速率常数相对于Millia水分别降低了61%和56%，这主要是由于PFOS和PFOA的存在。在本研究中，我们评估了各种有机化合物对全氟辛烷磺酸和全氟辛酸声化学分解速率的影响。环境基质中的有机成分可能通过在气泡-水界面上的竞争性吸附或在瞬态气泡破裂事件中降低平均界面温度来降低全氟辛烷磺酸和全氟辛烷磺酸的声化学降解率。单个有机化合物的作用取决于朗缪尔吸附常数、亨利定律常数、比热容和总的离解吸热。挥发性有机物（VOCs）是垃圾填埋场地下水中全氟辛烷磺酸（PFOS）和全氟辛烷磺酸（PFOA）声化学速率降低的主要原因，而溶解性天然有机物（DOM）的影响不显著。最后，臭氧化和声波溶解相结合的过程显示，基本上恢复了垃圾填埋场地下水中全氟辛烷磺酸和全氟辛烷磺酸的速率损失。
Perfluorinated chemicals such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are environmentally persistent and recalcitrant to most conventional chemical and microbial treatment technologies. In this paper, we show that sonolysis is able to decompose PFOS and PFOA present in groundwater beneath a landfill. However, the pseudo first-order rate constant for the sonochemica I degradation in the landfill groundwater is reduced by 61 and 56% relative to Millia water for PFOS and PFOA, respectively, primarily due to the presence of other organic constituents. In this study, we evaluate the effect of various organic compounds on the sonochemical decomposition rates of PFOS and PFOA. Organic components in environmental matrices may reduce the sonochemical degradation rates of PFOS and PFOA by competitive adsorption onto the bubble-water interface or by lowering the average interfacial temperatures during transient bubble collapse events. The effect of individual organic compounds depends on the Langmuir adsorption constant, the Henry's law constant the specific heat capacity, and the overall endothermic heat of dissociation. Volatile organic compounds (VOCs) are identified as the primary cause of the sonochemical rate reduction for PFOS and PFOA in landfill groundwater, whereas the effect of dissolved natural organic matter (DOM) is not significant. Finally, a combined process of ozonation and sonolysis is shown to substantially recover the rate loss for PFOS and PFOA in landfill groundwater.