Department of Geological Sciences and Environmental Studies, Binghamton University, 4400 Vestal Pkwy E, Vestal, NY 13850, USA.
Biochemistry, Binghamton University, 4400 Vestal Pkwy E, Vestal, NY 13850, USA.
Environ Sci Process Impacts. 2022 Feb 23;24(2):196-208. doi: 10.1039/d1em00465d.
Per- and polyfluoroalkyl substances (PFAS) are persistent chemicals and have been detected throughout the environment. Thermal treatment is the most common remediation approach for PFAS-contaminated solid wastes. Although various thermal treatment techniques have demonstrated the potential to destruct PFAS, the fate of PFAS, removal efficacy, potential emissions, and the formation of incomplete combustion products during thermal treatment are little known. This study provides a critical review on the behavior of PFAS based on different types of thermal treatment technologies with various PFAS-impacted environmental medias that include water, soil, sewage sludge, pure PFAS materials, and other PFAS-containing wastes. Different extents of PFAS thermal destruction are observed across various thermal treatment techniques and operating conditions. PFAS removal and destruction efficiencies rely heavily on PFAS structures, the complex combustion chemistry, the presence or absence of oxygen, temperature, and other operational conditions. This review also covers proposed PFAS thermal destruction mechanisms. Different thermal destruction mechanisms for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS), and other PFAS are reviewed and compared. The majority of studies about PFAS thermal destruction mechanisms were focused on a specific list of PFAS and based mostly on the pyrolysis treatment. The basic pathway for PFAS destruction during pyrolysis is hydrodefluorination, which could be largely influenced by the alkaline condition. Future field-scale research that involves the characterization of PFAS destruction products and incomplete combustion products is needed to address public concerns and better emission control.
全氟和多氟烷基物质（PFAS）是持久性化学物质，已在环境中被广泛检测到。热处理是处理 PFAS 污染固体废物最常见的修复方法。虽然各种热处理技术已被证明有潜力破坏 PFAS，但 PFAS 的命运、去除效果、潜在排放以及在热处理过程中不完全燃烧产物的形成仍知之甚少。本研究基于不同类型的热处理技术，对受各种 PFAS 影响的环境介质（包括水、土壤、污水污泥、纯 PFAS 材料和其他含 PFAS 的废物）中的 PFAS 行为进行了批判性评估。在各种热处理技术和操作条件下，观察到 PFAS 的热破坏程度存在不同程度的差异。PFAS 的去除和破坏效率在很大程度上取决于 PFAS 的结构、复杂的燃烧化学、氧气的存在与否、温度和其他操作条件。本综述还涵盖了 PFAS 热破坏机制的建议。对全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）以及其他 PFAS 的不同热破坏机制进行了综述和比较。大多数关于 PFAS 热破坏机制的研究都集中在特定的 PFAS 清单上，并且主要基于热解处理。在热解过程中，PFAS 破坏的基本途径是加氢脱氟，这可能会受到碱性条件的很大影响。需要进行未来的现场规模研究，涉及 PFAS 破坏产物和不完全燃烧产物的特征描述，以解决公众关切并更好地进行排放控制。
