Pilot-scale performance of a UV-regenerable Iron-based activated carbon system for pharmaceutical and PFAS removal

Emerging contaminants (ECs), particularly per - and polyfluoroalkyl substances (PFAS) and pharmaceuticals (PhACs), are challenging to treat because of their persistence, mobility, and weak adsorption. We constructed and continuously operated a 200 m 3 ·day −1 pilot at a municipal wastewater treatment plant (WWTP) in Daegu, South Korea, coupling iron-impregnated powdered activated carbon (Fe-PAC) with ultraviolet (UV)/H₂O₂ photo-regeneration to restore adsorption in situ. Bench tests verified Fe-site-enabled photo-Fenton reactions, and pilot-assessed robustness under actual, variable influent fluctuations. Without regeneration, short-chain PFAS (PFHxA and PFHpA) showed limited, unstable removal, whereas long-chain PFNA and PFOA decreased over time owing to site saturation. Most PhACs (diclofenac, and florfenicol) sustained ≥90% removal; hydrophilic caffeine decreased transiently but recovered after regeneration, whereas atenolol exhibited lower long-term stability. With periodic UV/H₂O₂ treatment, PFAS removal exceeded 95% after three months; aggregate removal reached 97.7 and 99.1% at three and five months, respectively, without deterioration of water-quality indicators. Mechanistically, Fe-PAC acted as a dual adsorbent–catalyst: pores captured contaminants, and Fe sites generated radicals that decomposed surface residues and reopened adsorption sites, providing pilot-scale evidence that the UV-regenerable Fe-PAC hybrid can overcome adsorption limitations and deliver robust control of persistent micropollutants. We recommend optimizing the regeneration frequency and intensity and performing techno-economic evaluations to support full-scale deployment. • A 200 m 3 ·day −1 Fe-PAC/UV pilot ran >6 months on real WWTP effluent. • Fe-PAC: dual adsorbent–catalyst; enables in-situ UV/H₂O₂ regeneration. • UV/H₂O₂ regeneration restored sites; PFAS removal >95% after 3 months. • Most pharmaceuticals kept >90% long-term removal. • Demonstrated scalable control of persistent micropollutants in practice.