Purpose of Review

The unique properties of per- and polyfluoroalkyl substances (PFASs) have seen their widespread adoption, subsequent accumulation in the environment and concern regarding potential environmental effects. Globally, airfields and paved firefighting training surfaces are hotspots for accumulation of PFAS due to extensive use of aqueous film-forming foams (AFFF). Evidence from contaminated concrete and asphalt airfield and training pavements suggests they may serve as an enduring PFAS source. This review investigates sealants as remediation technologies to minimise PFAS mobilisation from pavements drawing on current knowledge of remediation options for soils, sediments, surface and groundwaters.

Recent Findings

The review did not identify any published sealant information specific to PFAS. Our analysis showed that surface and penetrative sealants may offer an immediate solution via encapsulation of PFAS residues in concrete and asphalt. The most promising surface sealants likely to minimise water ingress and PFAS leaching are selected polymers and (modified) bitumen, owing to the relatively low cost, good adhesion, trafficability and chemical, heat and UV resistance. Potential also exists to enhance PFAS immobilisation using additives to absorb or otherwise chemically bind PFAS. Prospective penetrative sealants include silicates or siloxanes that bind to internal mineral surfaces and/or fill pores to restrict PFAS mobility. It is likely that combinations of surface and penetrative sealants will be required to meet functional, operational and management requirements with respect to new or existing contamination in concrete or asphalt pavements.

Summary

At present, few if any sealants have been evaluated for their ability to bind or mitigate PFAS mobility. This review serves as a starting point for further studies to evaluate their short or long-term effectiveness in immobilisation of PFAS residues in in situ or ex situ concrete and asphalt. Several knowledge gaps along with suggestions for future research have been made.

中文翻译：

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受 PFAS 污染的混凝土和沥青的密封剂和其他管理策略

审查目的

全氟烷基物质和多氟烷基物质 (PFAS) 的独特性质已被广泛采用，随后在环境中积累，并引起人们对潜在环境影响的关注。在全球范围内，由于广泛使用水成膜泡沫 (AFFF)，机场和铺设的消防训练场地成为 PFAS 积累的热点地区。来自受污染的混凝土和沥青机场以及训练路面的证据表明，它们可能是持久的 PFAS 来源。本综述利用当前对土壤、沉积物、地表水和地下水修复方案的了解，研究了密封剂作为修复技术，以最大限度地减少路面中 PFAS 的迁移。

最近的发现

该审查未发现任何针对 PFAS 的公开密封剂信息。我们的分析表明，表面密封剂和渗透密封剂可以通过将 PFAS 残留物封装在混凝土和沥青中来提供直接的解决方案。最有前途的表面密封剂可以最大限度地减少水的侵入和 PFAS 浸出，是精选的聚合物和（改性）沥青，因为其成本相对较低，具有良好的附着力、可流通性以及耐化学性、耐热性和耐紫外线性。还存在使用添加剂吸收或以其他方式化学结合 PFAS 来增强 PFAS 固定的潜力。预期的渗透性密封剂包括硅酸盐或硅氧烷，它们与内部矿物表面结合和/或填充孔隙以限制 PFAS 的流动性。可能需要表面密封剂和渗透密封剂的组合来满足功能性、

概括

目前，很少有密封剂结合或减轻 PFAS 迁移性的能力得到评估。本综述可作为进一步研究的起点，以评估其在原位或异位混凝土和沥青中固定 PFAS 残留物的短期或长期有效性。提出了一些知识差距以及对未来研究的建议。