Long-time enrofloxacin processing with microbial fuel cells and the influence of coexisting heavy metals (Cu and Zn)

Abstract

Antibiotics and heavy metals always coexist in livestock wastewater, and the effect of their coexistence on antibiotic degradation by microbial fuel cells (MFCs) remains unclear. In this study, enrofloxacin served as an electron donor for MFCs that had operated for 10 months with Cu and Zn in the influent. After 10 months of acclimation, the MFCs showed good performance for electricity production and enrofloxacin degradation, with a maximum power density of 244.2 ± 20.3 mW/m2, chemical oxygen demand (COD) removal efficiency of 87.3 ± 1.5%, and enrofloxacin degradation rate of 67.6 ± 7.1%. The presence of Zn and enrofloxacin contributed to improving the power output of the MFCs to different extents, while Cu addition and electrical stimulation could strengthen the capability of the MFCs towards antibiotics removal. The coexistence of heavy metals can stabilise the performance of MFCs in response to changes in COD or enrofloxacin concentrations. Comamonas has high adaptability to wastewater with heavy metals and antibiotics coexisting and may be a functional bacterium for MFCs to produce electricity and degrade antibiotics.