Enhanced Removal of Veterinary Antibiotic Florfenicol by a Cu-Based Fenton-like Catalyst with Wide pH Adaptability and High Efficiency

The study on the removal of refractory veterinary antibiotic florfenicol (FF) in water is still very limited. In this study, an efficient Fenton-like catalyst was developed by synthesizing a series of Cu-based multi-metal layered double hydroxides (CuNiFeLa-LDHs) to degrade FF in aqueous solution. In the experiments, the screened CuNiFeLa-2-LDH with the molar ratio of La3+/(Fe3+ + La3+) = 0.1 exhibited high catalytic activity, achieving almost complete degradation of 5 mg L-1 FF under 5 mmol L-1 H2O2 conditions. The mechanisms revealed that the enhanced catalytic performance was ascribed to the existence of Ni which accelerated the electron transfer rate and La which served as a Lewis acidic site to provide more reactive sites in this Cu-dominated Fenton-like reaction, further generating (OH)-O-center dot, O-center dot(2)-, and O-2(1) as active species to attack pollutants directly. Interestingly, the catalyst showed a wide pH adaptability and little release of copper ions to the solution. The regenerated CuNiFeLa-2-LDH is demonstrated to be a stable and reliable material for florfenicol degradation.