Microbial electro-Fenton: A promising system for antibiotics resistance genes degradation and energy generation

The widespread use of antibiotics has accelerated the development of antibiotic resistance genes (ARGs), which are now recognized as emerging environmental contaminants that pose a high risk to public health. In this study, simultaneous antibiotic and ARGs removal and bioelectricity generation was explored in a microbial electro-Fenton system using erythromycin (ERY) as a model antibiotic compound. The results showed that ERY could be degraded, with an average removal efficiency of 88.73% in 48 h, and the average removal efficiency of chemical oxygen demand in the microbial electro-Fenton with 50 μg L⁻¹ ERY reached 86.84% in 48 h, which was lower than that in the control group (89.11%). The produced ARGs were analyzed and degraded in a cathode chamber. The quantity of ermB was significantly reduced, with log removal reaching a value of 1.96. More importantly, all erm genes (ermB, ermC, ermG) showed a tendency to be degraded. Furthermore, the maximum power density obtained with respect to the electrode area was 0.193 W m⁻² when ERY was added, corresponding to a current density of 0.583 A m⁻² (external resistor = 1000 Ω), which was 14% larger than that of the control group (0.169 W m⁻²). The results of this study demonstrate the potential of microbial electro-Fenton for ERY and ARGs removal.