Electricity Generation and Tetracycline Removal Performance of a Sediment Microbial Fuel Cell (SMFC) Employing GO/SiO₂ Modified Anode in Mariculture Tailwater Treatment

Mariculture tailwater typically contains a certain concentration of antibiotics; however, conventional biological treatment methods struggle to effectively remove these antibiotics. Therefore, in this study, we modified the carbon felt (CF) anode in sediment microbial fuel cells (SMFCs) to enhance tetracycline (TC) removal in mariculture systems. We fabricated a novel composite material by integrating instant freeze-drying technology with the solvothermal reaction method to combine graphene oxide (GO) and nanoscale SiO₂. Subsequently, the composite material was incorporated into CF for anodic modification, resulting in improved performance of SMFCs in TC removal and electricity generation. The maximum power density achieved was 63.72 mW/m², nearly 2.9 times higher than that of the unmodified anode. Modified SMFCs exhibited a twofold increase in the degradation rate of tetracycline compared to natural degradation alone and showed significant improvements compared to both the control group and conditions with only GO addition. Furthermore, the modified anode effectively enriched populations of Leisingera, Oceanimonas, and Halomonas, thereby significantly enhancing the electrochemical performance of the SMFCs. This study successfully demonstrates the application of a modified-anode SMFC using a composite material consisting of GO and SiO₂ for on-site removal of TC from mariculture environments.