Self-corroding microelectrolysis enhanced membrane aeration electroactive biofilm for antibiotic and antibiotic resistance gene reduction

A three-dimensional bioelectrochemical system was developed by coupling self-corrosive Fe/C microelectrodes with a membrane-aerated electroactive biofilm reactor (IC-MAEBR) to enhance antibiotic and antibiotic resistance gene (ARG) reduction. The IC-MAEBR significantly enriched aromatic proteins as dominant fluorescent components in cathode biofilms, while exhibiting an elevated α-helix to (β-sheet + random coil) (62.8%), enhanced biofilm density. Besides, the coordinated action of applied potential and microelectrolysis reduced sul1 and sul2 abundances in cathode biofilms by −2.6 log₂ and −1.6 log₂, respectively, primarily through host microorganism inactivation. Although higher potential differences (0.75 V) narrowed SMX removal difference between membrane-aerated electroactive biofilm reactors (MAEBR) and IC-MAEBR, IC-MAEBR demonstrated superior performance at lower potentials (0.5 V), achieving rapid SMX degradation within 12 h and maintained accelerated removal kinetics even post-discharge cycles, outperforming MABR and MAEBR by 4.2 μg/L/h and 9.7 μg/L/h, respectively. This study provides new insights into microelectrolysis enhanced electroactive-biofilm in antibiotics and ARGs removal.