Biomimetics-inspired chlorine activation for targeted control of emerging contaminants in municipal wastewater.

Municipal wastewater effluent is a major source of emerging contaminants which often persist through conventional treatment processes. Current advanced oxidation processes can help but require extra energy input and infrastructure upgrades, so there is a need for retrofitting technologies that could enhance contaminants abatement within existing processes with minimal added cost. Since chlorination is a widely used disinfection step prior to the discharge of effluent, we use low-cost, biodegradable amino carboxylate ligands to modulate Mn(III) center, mimicking the metalloenzymes to activate chlorine for achieving selective degradation of contaminants in real municipal wastewater. The decontamination process is mediated by electrophilic Mn(V)-oxo intermediates, enabling broad-spectrum degradation of contaminants via multiple pathways. We established experimental protocols and theoretical framework by integrating isotope probing, high-resolution mass spectrometry, and computational modeling based on density functional theory for understanding the behaviors of high-valence manganese-oxo intermediates in aqueous decontamination processes. Our study offers a practical and innovative paradigm for retrofitting existing wastewater treatment infrastructure. By introducing trace‑level (0.1 mg as Mn/L) biodegradable manganese complexes into the chlorination step, targeted removal of emerging contaminants can be achieved without overhauling the treatment processes. This work might inject new vitality into chlorination, as one of the greatest public sanitation achievements of the 20th century, equipping it to meet the contemporary global challenge posed by anthropogenic contaminants.