Investigating the Atmospheric Sources and Sinks of Perfluorooctanoic Acid Using a Global Chemistry Transport Model
Investigating the Atmospheric Sources and Sinks of Perfluorooctanoic Acid Using a Global Chemistry Transport Model
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DOI：
10.3390/atmos11040407
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发表时间：
2020-04
期刊：
影响因子：
2.9
通讯作者：
Rayne Holland;M. Khan;R. Chhantyal-Pun;A. Orr-Ewing;C. Percival;C. Taatjes;D. Shallcross
中科院分区：
文献类型：
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作者：
Rayne Holland;M. Khan;R. Chhantyal-Pun;A. Orr-Ewing;C. Percival;C. Taatjes;D. Shallcross
全氟辛酸是我们大气中许多令人担忧的污染物之一；它对环境退化过程具有高度的抵抗力，使其能够在生物上积累。随着这种化学品进入环境的直接途径减少，作为全氟辛烷磺酸工业阶段淘汰的结果，更重要的是准确地模拟间接生产途径的影响，例如前体的环境退化；例如，含氟调聚物醇(FTOHs)。本文利用三维全球化学输送模式STOCHEM-CRI研究了全氟辛酸及其前体FTOHs在对流层中的化学、物理损失和输送。此外，这项研究包括通过添加稳定的Criegee中间体，在大气中损失全氟辛酸的一个重要过程，在此称为“Criegee领域”。虽然与Criegee中间体的反应是全氟辛酸在大气中的一个重要损失过程，但这并不会导致其从大气中永久消除。全氟辛酸与Criegee中间体反应生成的过氧化氢产物在大气中的去向导致全氟辛酸的生产通量增加了≈0.04GG年−1。此外，过氧化氢产物从大气中的物理损失(即沉积)，在降低大气浓度的同时，也可能导致环境水相，如云、降水、海洋和湖泊中全氟辛酸的变化。因此，“克里吉场”促进的清除很可能只会加速全氟辛酸向地表的转移(预计全氟辛酸在大气中的寿命将减少10小时，平均从没有克里吉损失时的约80小时减少到有克里吉损失时的70小时)。
Perfluorooctanoic acid, PFOA, is one of the many concerning pollutants in our atmosphere; it is highly resistant to environmental degradation processes, which enables it to accumulate biologically. With direct routes of this chemical to the environment decreasing, as a consequence of the industrial phase out of PFOA, it has become more important to accurately model the effects of indirect production routes, such as environmental degradation of precursors; e.g., fluorotelomer alcohols (FTOHs). The study reported here investigates the chemistry, physical loss and transport of PFOA and its precursors, FTOHs, throughout the troposphere using a 3D global chemical transport model, STOCHEM-CRI. Moreover, this investigation includes an important loss process of PFOA in the atmosphere via the addition of the stabilised Criegee intermediates, hereby referred to as the “Criegee Field.” Whilst reaction with Criegee intermediates is a significant atmospheric loss process of PFOA, it does not result in its permanent removal from the atmosphere. The atmospheric fate of the resultant hydroperoxide product from the reaction of PFOA and Criegee intermediates resulted in a ≈0.04 Gg year−1 increase in the production flux of PFOA. Furthermore, the physical loss of the hydroperoxide product from the atmosphere (i.e., deposition), whilst decreasing the atmospheric concentration, is also likely to result in the reformation of PFOA in environmental aqueous phases, such as clouds, precipitation, oceans and lakes. As such, removal facilitated by the “Criegee Field” is likely to simply result in the acceleration of PFOA transfer to the surface (with an expected decrease in PFOA atmospheric lifetime of ≈10 h, on average from ca. 80 h without Criegee loss to 70 h with Criegee loss).