Zhu Xuemei, Yang Chao, Du Qing, Wang Wenhan, Lü Changwei, Sun Hongwen, Liao Chengmei, Wang Xin
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China.
Ocean College, Hebei Agricultural University, 52# Hebei Street, Qin Huangdao, 066000, China.
Environ Sci Technol. 2025 Jul 1;59(25):12417-12436. doi: 10.1021/acs.est.5c04015. Epub 2025 Jun 19.
Per/polyfluoroalkyl substances (PFASs), characterized by their ultrastable C-F bonds and pervasive environmental persistence, present critical remediation challenges due to their recalcitrance and bioaccumulative potential. Conventional oxidative degradation methods predominantly yield bioaccumulative short-chain fluorinated derivatives, failing to achieve molecular annihilation. We highlight reductive defluorination as a transformative strategy to directly cleave C-F bonds and mitigate toxicity through two distinct electron-transfer modalities: indirect routes mediated by reactive species (e.g., hydrated electrons/active hydrogen) contrasted with direct mechanisms employing biocatalytic or electrochemical systems for targeted electron injection. Mechanistic taxonomy and quantitative structure-reactivity analyses reveal that defluorination efficiency is governed by the molecular architecture (e.g., chain length and fluorination patterns) and operational parameters (e.g., pH, redox potentials, and solution matrices). While standalone reductive technologies face scalability constraints from energy intensity and secondary contamination risks, synergistic integration of bioremediation-electrochemical-photocatalytic systems demonstrates enhanced defluorination efficiency. By coupling molecular-level degradation mechanisms with modular engineering, we propose future directions for developing reductive defluorination, offering a sustainable pathway to eliminate environmental recalcitrance and comply with evolving global water quality mandates.
全氟/多氟烷基物质（PFASs）具有超稳定的碳氟键和普遍的环境持久性，因其难降解性和生物累积潜力而带来严峻的修复挑战。传统的氧化降解方法主要产生具有生物累积性的短链氟化衍生物，无法实现分子消除。我们强调还原脱氟是一种变革性策略，可通过两种不同的电子转移方式直接裂解碳氟键并降低毒性：由活性物种（如水合电子/活性氢）介导的间接途径与采用生物催化或电化学系统进行靶向电子注入的直接机制形成对比。机理分类和定量结构-反应性分析表明，脱氟效率受分子结构（如链长和氟化模式）和操作参数（如pH值、氧化还原电位和溶液基质）的控制。虽然单一的还原技术面临能量强度和二次污染风险带来的可扩展性限制，但生物修复-电化学-光催化系统的协同整合显示出更高的脱氟效率。通过将分子水平的降解机制与模块化工程相结合，我们提出了未来发展还原脱氟的方向，为消除环境难降解性和符合不断演变的全球水质要求提供了一条可持续途径。
