Optimization of photo-fenton process with Fe@Fe₂O₃ nanowires for carbamazepine degradation in wastewater

Pharmaceutical contaminants such as carbamazepine (CBZ) are frequently detected in aquatic environments due to their widespread use and resistance to conventional wastewater treatment. CBZ poses serious ecological and health risks, including endocrine disruption and neurotoxicity. This study systematically evaluated the efficiency of the Fe@Fe₂O₃ nanowire-assisted photo-Fenton process for CBZ degradation in aqueous solutions. Batch experiments were conducted using a UV-C photoreactor under various conditions: pH (4–7), CBZ concentration (7–15 mg/L), catalyst dosage (350–1050 mg/L), reaction time (5–25 min), FeSO₄·7H₂O and H₂O₂ concentrations, and UV intensity (0.15–0.45 mW/cm²). Sample preparation was conducted using dispersive liquid–liquid microextraction (DLLME), followed by quantification of CBZ via high-performance liquid chromatography (HPLC). The process optimization was carried out using Response Surface Methodology (RSM) employing a Box–Behnken Design (BBD). Maximum CBZ removal efficiency (100%) was achieved at pH 4.9, UV intensity 2.3 mW/cm², H₂O₂ concentration 5.5 mg/L, FeSO₄·7H₂O concentration 7.5 mg/L, catalyst dosage 758 mg/L, and reaction time 15.2 min. Results demonstrate that the Fe@Fe₂O₃-assisted photo-Fenton process is a highly effective advanced oxidation technique for CBZ removal from contaminated water. Furthermore, the RSM-BBD model accurately optimized the process parameters, achieving maximum degradation efficiency under optimal conditions.