Potassium Ferrate as a Novel Anti-Biofouling Agent for Invasive Freshwater Mussels: Multi-Omics Insights and Pilot-Scale Validation

Invasive species like freshwater mussels extensively colonize water distribution systems, posing a significant threat to the safety and performance of hydraulic infrastructure. The demand for innovative technologies that balance efficacy, environmental safety, and sustainability for biofouling control is growing. This study explores the potential of potassium ferrate [Fe(VI)], a green oxidant, as an effective antifouling agent. Using <i>Limnoperna fortunei</i> as a model organism, we demonstrated that Fe(VI) exerts dose-dependent control over biofouling. Larval viability decreased by 62.48% (<i>p</i> < 0.05) after 1 h of exposure to 0.1 mg·L^-1, while adult mussels exposed to concentrations of 0.1, 0.25, 0.5, and 0.7 mg·L^{- 1} for 7 days exhibited up to a 78.79% loss in byssal tensile strength. Further analyses suggested that Fe(VI) induced oxidative stress, microbiota dysbiosis, metabolic disruption, and downregulation of protein synthesis, collectively impairing mussel viability. Moreover, Fe(VI) directly oxidizes structural proteins in the byssus and enhances iron complexation with 3,4-dihydroxyphenylalanine (DOPA) residues at the plaque interface, leading to impaired adhesive capacity. The effectiveness, safety, and environmental compatibility of Fe(VI) were further validated in pilot-scale trials at an operational water treatment facility. This study underscores the promise of Fe(VI) as a sustainable and efficient green strategy for mitigating mussel biofouling in hydraulic systems─especially in water treatment facilities with stringent water quality requirements.