Carbamazepine (CBZ) is an anticonvulsant pharmaceutical that is resistant to photodegradation and biodegradation in conventional wastewater treatment plants. In this research, the degradation of commercial CBZ was studied using a boron-doped diamond-Fe system in continuous flow. A response surface model was created to determine the contributions of the current intensity (0.39, 0.50, 0.75, 1.00, and 1.10 A) or current density (1.69, 2.16, 3.25, 4.33, and 4.76 mA/cm², respectively), support electrolyte (NaCl and CaCl₂), and initial CBZ concentration ([CBZ]₀) (0.1, 1.0, 5.5, 10.0, and 11.8 mg/L). The highest CBZ removal (%) was achieved with NaCl as a support electrolyte at a current intensity of 0.64 A (2.77 mA/cm²) and [CBZ]₀ of 4.5 mg/L at a neutral pH (6–7) and a treatment time of 120 min. The electro-oxidation (EO) process achieved a removal efficiency of 77.25%, whereas solar EO removed 90.77% of CBZ in the presence of ultraviolet radiation (536.37 W/m²). CBZ degradation was fitted to the Behnajady–Modirshahla–Ghanbery kinetic model with constant values of 1/m = 0.31 and 1/b = 0.93, thereby indicating the fast decomposition of CBZ. The toxicity was significantly reduced in the effluent. Graphical abstract

The Electro-Fenton (EF) process is a promising technology for the sustainable remediation of organic contaminants in complex wastewater. In this study, a weak magnetic field (~150 G) was applied to enhance the performance of an EF system using magnetite (Fe₃O₄) synthesized by a controlled co-precipitation route as a recyclable solid iron source. The magnetite was characterized by FTIR, SEM/EDS, and XPS, confirming the coexistence of Fe²⁺/Fe³⁺ species essential for in situ Fenton-like reactions. Under the selected operating conditions (90 min reaction time), magnetic-field assistance improved methylene blue decolorization from 14.2% to 46.0% at pH 3. FeSO₄ was used only as a homogeneous benchmark, whereas the magnetite-based system operated without soluble iron addition, minimizing sludge formation and secondary contamination. These results demonstrate the potential of magnetite-assisted and magnetically enhanced EF systems as a low-cost, sustainable alternative for the treatment of dye-containing industrial wastewater and other complex effluents.