Photochemical decomposition of perfluorooctanoic acid mediated by iron in strongly acidic conditions.

Highlights: [•] Perfluorooctanoic acid (PFOA) was decomposed based on ferric ion performance. [•] Complete decomposition of PFOA was confirmed in strongly acidic conditions. [•] Fe2+ changed to Fe3+ to restore chemical equilibrium in this condition. [•] Fe3+ was only produced from Fe2+ by hydroxyl radical in weakly acidic conditions. [•] The Fe3+ regeneration mechanisms resulted in the performance of Fe3+ for PFOA. [ABSTRACT FROM AUTHOR]