Hydrothermal Alkaline Treatment for Destruction of Per- and Polyfluoroalkyl Substances in Aqueous Film-Forming Foam
Hydrothermal Alkaline Treatment for Destruction of Per- and Polyfluoroalkyl Substances in Aqueous Film-Forming Foam
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DOI：
10.1021/acs.est.0c06906
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发表时间：
2021-02-08
影响因子：
11.4
通讯作者：
Strathmann, Timothy J.
中科院分区：
文献类型：
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作者：
Hao, Shilai;Choi, Youn-Jeong;Strathmann, Timothy J.
在消防活动中广泛使用水成膜泡沫(AFFF)(例如，灭火培训以扑灭飞机设施中的燃料火)已导致地下水和土壤受到全氟烷基物质和多氟烷基物质的广泛污染，这些物质高度抵抗使用传统处理技术进行破坏。本研究报道了水热碱处理AFFFS中存在的各种PFASs。全氟辛烷磺酸的定量和半定量高分辨率质谱分析表明，在近临界温度和压力(350摄氏度，16.5兆帕)下，在用碱(如1-5M氢氧化钠)修正的水中，两种全氟辛烷基甲酸酯(基于磺酸盐和含氟弹性体的配方)中鉴定的所有109种全氟辛烷磺酸均能迅速降解。这包括全氟烷基酸和多氟烷基酸以及一系列酸前体。当用5M氢氧化钠处理时，大多数全氟烷基磺酸盐在15分钟内被降解到检测不到的水平，而最顽固的全氟烷基磺酸盐在30分钟内被降解。F-19核磁共振波谱分析和氟离子分析证实，PFASs在稀释和浓缩AFFF混合气中几乎完全脱氟，气相色谱-质谱联用分析没有检测到反应器顶空气体中稳定的挥发性有机氟物种。这些发现表明，水热处理技术在管理全氟辛烷磺酸废流方面有很大潜力，包括现场处理未使用的AFFF化学品储存、调查产生的废物和集中来源区材料。
The widespread use of aqueous film-forming foam (AFFF) for firefighting activities (e.g., fire training to extinguish fuel-based fires at aircraft facilities) has led to extensive groundwater and soil contamination by per- and polyfluoroalkyl substances (PFASs) that are highly recalcitrant to destruction using conventional treatment technologies. This study reports on the hydrothermal alkaline treatment of diverse PFASs present in AFFFs. Quantitative and semiquantitative high-resolution mass spectrometry analyses of PFASs demonstrate a rapid degradation of all 109 PFASs identified in two AFFFs (sulfonate- and fluorotelomer-based formulations) in water amended with an alkali (e.g., 1-5 M NaOH) at near-critical temperature and pressure (350 degrees C, 16.5 MPa). This includes per- and polyfluoroalkyl acids and a range of acid precursors. Most PFASs were degraded to nondetectable levels within 15 min, and the most recalcitrant perfluoroalkyl sulfonates were degraded within 30 min when treated with 5 M NaOH. F-19 NMR spectroscopic analysis and fluoride ion analysis confirm the near-complete defluorination of PFASs in both dilute and concentrated AFFF mixtures, and no stable volatile organofluorine species were detected in reactor headspace gases by the gas chromatography-mass spectrometry analysis. These findings indicate a significant potential for application of hydrothermal treatment technologies to manage PFAS waste streams, including on-site treatment of unused AFFF chemical stockpiles, investigation-derived wastes, and concentrated source zone materials.