Perfluorooctanoic acid (PFOA) is of emerging concern owing to its global distribution and environmental persistence. Efficient degradation approaches are so far limited. Herein, we demonstrate for the first time the photochemical degradation of PFOA under UV-A irradiation after adsorption on Fe-doped zeolites with molecular oxygen as the terminal oxidant. In a system containing 1 g L⁻¹ PFOA-loaded Fe-zeolites, outstanding PFOA decomposition (> 99 %) was achieved within 24 h under slightly acidic conditions (pH ≤ 5.5). Short-chain perfluorinated carboxylic acids (PFCAs) are the main intermediates, beside fluoride and CO₂. No PFOA degradation occurs with Fe-free zeolites or dissolved ferric ions. Furthermore, we investigated the effects of pH, inorganic ions and gas atmospheres on PFOA degradation. A photochemical degradation mechanism with zeolite-bound iron species as catalytic sites for carboxylate-to-metal charge transfer is proposed. The presented study offers a novel approach for the removal of the highly recalcitrant PFOA from contaminated waters.

全氟辛酸（PFOA）由于其全球分布和环境持久性而引起了人们的关注。迄今为止，有效的降解方法受到限制。在本文中，我们首次证明了在分子氧作为末端氧化剂吸附于掺铁沸石上后，UV-A辐照下PFOA的光化学降解。在含有1 g L ^-1负载PFOA的铁沸石的系统中，在弱酸性条件下（pH≤5.5），在24小时内可实现出色的PFOA分解（> 99％）。短链全氟羧酸（PFCA）是主要中间体，除了氟化物和CO _2以外。不含铁的沸石或溶解的铁离子不会发生PFOA降解。此外，我们研究了pH，无机离子和气体气氛对PFOA降解的影响。提出了一种光化学降解机理，以结合沸石的铁物种为羧酸盐到金属电荷转移的催化位点。提出的研究提供了一种从受污染的水中去除高度顽固的PFOA的新颖方法。