Biological Waste-Derived\nDual-Site Catalyst Empowers\nElectro-Fenton Systems to Sustainably Decontaminate Livestock Wastewater

Livestock and poultry industries are pivotal for meat\nproduction,\nbut produced wastewater with heavy pollution challenges environmental\nsustainability and public health. The electro-Fenton (EF) process,\ncapable of in situ production and activation of hydrogen peroxide,\nis promising for decontaminating recalcitrant pollutants, yet fabricating\na highly active bifunctional cathode catalyst across a broad pH range\nremains a bottleneck. Guided by green chemistry principles, we synthesized\na dual-site catalyst from biological waste to facilitate hydroxyl\nradical production. Combined experimental and theoretical investigations\nunveiled that the Fe<sub>2</sub>O<sub>3</sub> sites facilitated H<sub>2</sub>O<sub>2</sub> generation via catalyzing the oxygen reduction\nreaction, whereas Fe<sub>3</sub>N sites promoted in situ H<sub>2</sub>O<sub>2</sub> activation into hydroxyl radicals. This electrocatalyst,\nintegrated into a gas diffusion electrode, achieved stable, aeration-free\nmineralization of antibiotic contaminants at neutral pH with a low\nenergy consumption of just 0.94 kWh/g of removed total organic carbon.\nThe further development of a tandem system that coupled the anammox\nbioprocess with the EF process exhibited exceptional efficiency in\nboth nitrogen removal and tertiary purification of actual livestock\nwastewater, obviating the need for pH adjustments or Fenton reagent\nadditives. These findings underscore the potential scalability and\napplication of our proposed approach in promoting sustainable wastewater\nmanagement practices.