三氟乙酸的污染现状、趋势分析及对策

Trifluoroacetic acid (TFA), an ultra-short-chain per- and poly-fluoroalkyl substance (PFAS) with the increase of mass concentration in environmental, has become a new focus after long-chain PFAS. TFA is mainly generated from the degradation of fluorinated chemicals, including third-generation hydrofluorocarbons and fourth-generation hydrofluoroolefins used as ozone-depleting substance (ODS) replacements. Tetrafluoropropene exhibits a TFA molar conversion rate of up to 100%, making it a key TFA anthropogenic source. The mass concentration of TFA exceeds safety thresholds in some water bodies due to its high water-solubility and low bioaccumulation, causing harm to aquatic life, while current PFAS water treatment technologies fail to remove it effectively. Concerns are growing over its unknown risks as the mass concentration of TFA in the environment is increasing. To address TFA pollution, a unified global PFAS definition is recommended, aiming to incorporate TFA into regulations and to promote the development of the fifth-generation ODS, the substitute with zero ozone depletion potential, low global warming potentia, and no TFA degradation.