A homogeneous persulfate (PS) activation under low energy consumption ultraviolet lightemitting diodes (UV-LEDs) was established in order to degrade the resistive fluoxetine-hydrochloride drug in aqueous media. For this aim, a falling film photo-reactor, equipped with four arrays of six UVLEDs (395 nm, 1Weach), was utilized. Trace concentrations of ferrous sulfate and heating the media could significantly improve the degradation efficiency. Under the established optimal conditions of 100 mg/L of persulfate, 1 mg/L of ferrous sulfate, natural pH of 6.4 and temperature of 40 C, a 71.1% degradation efficiency was achieved for 40 mg/L fluoxetine initial concentration after 50 min. The kinetic study revealed a pseudo-first order overall degradation rate. Based on scavenger quenching results, it was revealed that the hydroxyl radical and sulfate anion radical had, respectively, 52.3 and 31.4% contribution in degradation. To extend results to real conditions, the influence of inorganic cations/anions and also humic acid was investigated. FromLC-MSanalysis results, the transformation products were identified and three degradation pathways were proposed. Interestingly, a cost evaluation indicated electrical energy consumption of 16.7 kWh/m3 and operating cost of only $1.71 per each cubic meter. Consistently, the profound UV-LED/PS/Fe2þ/heat process exhibited desired capabilities in scenarios for treating resistive drug wastewaters.
