Photocatalytic degradation of trace ciprofloxacin using LED light strips coated with a MOF-composite

The purpose of this study was to explore the photocatalytic degradation of ciprofloxacin (CIP)-a fluoroquinolone-using a bench-top photoreactor equipped with energy-efficient UV LED (395 nm) light strips coated with a catalyst. The photocatalyst coating was synthesized by integrating a novel copper-based metal-organic framework (MOF) with titanium dioxide nanoparticles to activate both pollutant adsorption and photodegradation processes. Batch experiments were conducted to evaluate the catalyst's (TiO₂/HKUST-1) efficiency in degrading fluoroquinolone-type antibiotics as a function of the initial CIP concentration, catalyst concentration in the coating material, irradiation time, and system geochemistry, including temperature. The longevity of the catalyst, including potential leaching of metal ions from the catalyst coating, was examined under dynamic, flow-through conditions in the baffled reactor. The generation of reactive oxygen species (ROS) and advanced oxidation processes (AOPs), initiated by the TiO₂/HKUST-1 composite, degraded CIP (C₀ = 100 µg L^-1) by > 95% within 15 min. These results, including an assessment of the reactor's energy use, demonstrate that the catalyst coating on LED light strips enhances treatment efficiency by improving light absorption, facilitating efficient charge separation, and increasing the accessibility of active sites on the catalyst. This approach, with further optimization, could have practical and scalable applications in the decentralized (i.e., household-scale) treatment of aqueous-phase fluoroquinolone antibiotics.