Biovoltage-driven, sulfurized Fe-Co anode promoted the generation of salt source active species for enhanced...

Electrochemical advanced oxidation processes (E-AOPs) have emerged as a promising approach for effective antibiotic degradation in wastewater treatment systems. However, their practical implementation faces various challenges, including extra energy consumption, complex aqueous matrices, and potential risks of secondary pollution. To address these challenges, this study integrated bioelectricity generation, salt electrolytes (Na₂SO₄, NaCl, and NaNO₃), and a nickel foam-supported sulfur-modified iron-cobalt (S-Fe-Co@Ni) anode. Through in situ generation of reactive oxygen species from salt components in antibiotic wastewater, the S-Fe-Co@Ni anode efficiently removed various antibiotics, specifically ciprofloxacin hydrochloride (CIP·HCl·H₂O), tetracycline, and enrofloxacin, with a high reaction rate of 0.02668 min^-1 across a broad pH range. Owing to the synergistic effect of Fe and Co sites under sulfurization conditions, the CIP·HCl·H₂O removal efficiency of S-Fe-Co@Ni anode reached 92%, far higher than the corresponding values of Fe-Co@Ni, S-Fe@Ni, and S-Co@Ni anodes (72%, 58.6%, and 53.1%, respectively). The anode ultimately mineralized the considered antibiotics to CO₂ and H₂O. A mathematical model using interaction parameters successfully predicted the antibiotic degradation behavior in the presence of multiple antibiotics. Density functional theory calculations supported the proposed mechanism of antibiotic degradation by the S-Fe-Co@Ni anode in sulfate and chloride environments. A life cycle assessment corroborated the environmental benignity of the S-Fe-Co@Ni anode, thereby highlighting its potential for sustainable development. Overall, this research provides novel insights into the development of low-energy, green E-AOPs for treating antibiotic wastewater.