Enhancing Electron Utilization and Sulfamethoxazole Degradation in Microbial Electrochemical Systems Using MnCo2O4 Modified Electrodes

Abstract

The widespread use of antibiotics in pharmaceuticals and aquaculture has led to their high concentration in wastewater, posing threats to ecological stability and human health. In addressing these challenges, in our preliminary work, the embedding of microbial electrodes in a microbial electrochemical system (MES) demonstrated effective degradation of the antibiotic sulfamethoxazole (SMX) in aquatic environments. However, challenges persist, including low electron utilization efficiency and suboptimal antibiotic degradation rates. This study introduces the modification of microbial electrodes with the bimetallic oxide MnCo2O4 to enhance the electrochemical performance of the MES and the degradation efficiency of SMX. Electrochemical analysis revealed a reduction in system internal resistance by 18.99% following electrode modification. The specific capacitance of the microbial electrodes increased from 232.47 to 483.47 F/g. During operation, the MnCo2O4-modified electrodes exhibited a 12.41% increase in average SMX degradation efficiency compared to unmodified electrodes. Microbial community structure and correlation analysis indicated a significant rise in the richness and diversity of microbes on the modified electrodes. SMX-degrading bacteria such as Acetobacterium and Trichococcus were notably enriched. This research demonstrates the effectiveness of material-modified electrodes in enhancing electron utilization in microbial electrochemistry, while also offering insights into sustainable bioremediation strategies for surface water.