Department of Civil Engineering, McGill University, Montreal, Quebec, H3A 0C3, Canada; School of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
Department of Civil Engineering, McGill University, Montreal, Quebec, H3A 0C3, Canada; Department of Chemistry, Université de Montréal, Montréal, QC, Canada.
J Hazard Mater. 2019 Jan 15;362:140-147. doi: 10.1016/j.jhazmat.2018.09.021. Epub 2018 Sep 7.
Aqueous film forming foams (AFFFs) containing perfluoroalkyl and polyfluoroalkyl substances (PFASs) are commonly deployed to extinguish hydrocarbon fuel fires, resulting in petroleum hydrocarbons coexisting with PFASs in contaminated soil. Nutrient-amended and aerated biopiles used for petroleum hydrocarbon bioremediation could cause unintended transformation of polyfluorinated substances into perfluoroalkyl carboxylates (PFCAs). The study sought to examine environmental behaviors of PFASs in engineered treatment facilities by monitoring AFFF-derived PFASs under three nutrient conditions. The influence of nutrient levels on degradation kinetics and efficiency was found to vary between the two chemical classes and among individual PFASs. A high number of compounds including the zwitterionic polyfluoroalkyl betaines that have aged in the field for two years were continuously biotransforming in lab reactors, demonstrating their slow kinetics and environmental persistence. The low yield to PFCAs implies that the processes such as the formation of bound residues or irreversible sorption might play a major role in reducing detectable levels of zwitterionic PFASs. The high persistence of betaines was further confirmed by the behaviors of a freshly spiked sulfonamide betaine. The study demonstrated complex chemical dynamics in AFFF-impacted soils and the challenges for predicting the fate of PFASs in soil biopiling facilities.
水成膜泡沫（AFFF）含有全氟烷基和多氟烷基物质（PFAS），常用于扑灭碳氢化合物燃料火灾，导致石油碳氢化合物与污染土壤中的 PFAS 共存。用于石油烃生物修复的添加营养物质和充气的生物堆可能导致多氟化物质意外转化为全氟烷基羧酸（PFCAs）。本研究通过监测三种营养条件下源自 AFFF 的 PFAS，旨在检查工程处理设施中的 PFAS 环境行为。发现营养水平对两种化学物质类别和个别 PFAS 的降解动力学和效率的影响不同。大量化合物包括在现场老化两年的两性氟烷基甜菜碱，在实验室反应器中不断发生生物转化，表明其动力学缓慢且在环境中持久存在。PFCAs 的低产率意味着结合残留或不可逆吸附等过程可能在降低可检测水平的两性 PFAS 方面发挥主要作用。新添加的磺酰胺甜菜碱的行为进一步证实了甜菜碱的高持久性。该研究表明 AFFF 污染土壤中的化学动态复杂，以及预测土壤生物堆设施中 PFAS 命运的挑战。
