Energy-efficient degradation of antibiotics in microbial electro-Fenton system catalysed by M-type strontium hexaferrite nanoparticles

The enormous use and poor controls of life-saving antibiotics disturb the natural microbiome either directly or indirectly. This study investigates the removal of three veterinary antibiotics i.e., tetracycline, tylosin and sulfaquinoxaline in a set of H-type microbial electro-Fenton (MEF) system catalyzed by a novel M-type strontium hexaferrite nanoparticles (SrM-NPs) as heterogeneous Fenton catalyst. The system has degraded 85.9-88.2% of 10 mg L-1 antibiotics in 17 h, and complete degradation occurred within 24 h having total organic carbon removal of 74.8-87.2%. Conversely, 20% lower degradation of antibiotics is attained using homogenous Fenton catalyst (i.e. FeSO4) in 24 h. Current generation has led to anodic chemical oxygen demand oxidation ranging from 67.0 +/- 4.3% - 72.5 +/- 10.4% in concomitant with coulombic efficiency of 33-43% and maximum power output of 136.4 +/- 3.1 mW m(-2). Bacterial community analysis indicates that the dominant anodic bacteria belong to Proteobacteria (67.9 +/- 0.5%). Being prominent electroactive bacteria, Geobacter is found to 2%, however other detected genera might have played their role in the current production. Present results designate MEF system, a promising approach in terms of effective antibiotics removal in concomitant with electricity generation.