Microbial fuel cell powered Fenton degradation of ciprofloxacin from wastewater employing MIL-88B(Fe)-MOF-laser-induced graphene cathode.

Traditional electro-Fenton (EF) is efficacious for antibiotics removal but faces challenges like high energy demand, operational cost and the use of homogeneous catalysts that lead to secondary pollution and sludge generation by iron leaching. Microbial fuel cell (MFC)-power-driven Fenton offers a sustainable and green alternative by simultaneously producing electricity, beneficial for pollutant degradation. Herein, MIL-88B(Fe) supported on laser-induced graphene (MOF-LIG) composite cathode was fabricated via a single-step process and utilized in an MFC-Fenton process for the removal of antibiotic ciprofloxacin (CIP) wastewater. The MOF-LIG cathode facilitated in situ H2O2 generation (3.22 ± 0.075 mg L-1), 1.20 and 1.50 folds more than bare LIG and carbon felt (CF) electrodes, respectively. Thus, achieving 95.3 ± 3.0 % CIP removal during 180 min, following pseudo-first-order kinetics (k = 0.0155 min-1). Over 90 % of CIP abatement was noticed at acidic and neutral pH, whereas higher external resistance and pollutant doses inhibit the efficiency. Besides, a 42.4 ± 2.4 % reduction in total organic carbon was observed, revealing partial mineralization of CIP and its intermediates. The system attained a power density and coulombic efficiency of 250.2 ± 14.3 mWm-2 and 18.3 ± 1.1 %, respectively. The MOF-LIG cathode demonstrated superior stability, antifouling resistance, and efficient reusability, with minimal iron leaching. Importantly, 90.7 ± 3.6 % CIP removal was also achieved in secondary-treated real wastewater, validating the practical applicability of the process. Thus, integrating energy-positive MFC with stable, antifouling, and scalable single-step LIG electrodes, a cost-effective alternative to the EF process, advancing real-scenario pharmaceutical wastewater treatment can be achieved.