Abstract: Medical wastewater contains a large number of antibiotics, if discharged directly will cause immeasurable damage to the ecological environment. In this paper, the effects of novel boron-doped diamond (BDD) pulse electrocatalytic oxidation (PEO) technology on the efficient removal of levofloxacin (LFXN) in wastewater under different initial pH values (pH₀), current density (j), frequency (f), initial concentration (c(LFXN)) and electrolyte types were systematically investigated. The results showed that under the conditions of pH₀ = 3, j = 30 mA∙cm^-2, f = 100 Hz, c₀(LFXN) = 100 mg·dm⁻³ and c(Na₂SO₄) = 0.035 mol∙dm^-3, the COD removal efficiency (Re(COD)) was 94.4% and the energy consumption (EEC) was 81.43 kWh·m⁻³ after 120 min. COD can be efficiently removed without adding H₂O₂. Highly efficient 2e^－oxygen reduction (2e^－ORR) reaction to produce high concentration of H₂O₂ can be achieved by BDD-PEO technology. Under different pH and H₂O₂ conditions, the mineralization process of LFXN follows the pseudo-first-order reaction kinetics. The apparent rate constants increased in the order: pH = 7 < pH = 2.8 < pH = 7/c(H₂O₂) < pH = 2.8/c(H₂O₂). The possible mineralization pathway of LFXN was proposed by density functional theory (DFT) calculation to determine the active sites of the molecule and intermediate analysis.

Keywords : Pulse electrocatalytic oxidation; BDD electrode; Levofloxacin; Hydroxyl radical; Degradation mechanism.