A sustainable approach for efficient ammonium recovery, and simultaneous TOC removal from aqueous solutions by vesicle-like iron phosphate-based carbon nanomaterials.

NH is an ion with versatile potential; however, the release of wastewater containing this component, regardless of its high or low concentration, causes severe eutrophication in aquatic systems and contaminates numerous manufacturing processes. Thus, this study developed a sustainable method that can simultaneously remove, recover NH, polish water, oxidize organic matter, and yet release a material that can still be used as fertilizer. Regarding NH removal, FeP400 rapidly exhibited an exceptional NH uptake capacity (343.5 mg g) within 8 min, even in dairy processing wastewater with high NH concentrations and diverse co-existing components. FeP400 could oxidize organic compounds spontaneously to remove TOC, indirectly enhancing its NH uptake up to 33.5 % through charge balance mechanisms. The adsorption process involved both chemical (i.e., double-salt precipitation) and physical mechanisms (i.e., H-bonding and electrostatic interaction), as confirmed by thermodynamics, FT-IR, and XPS analyses. Regarding recovery, FeP400 can be reused for over 10 cycles with high removal (81 %) and NH recovery (88 %), a significant improvement over conventional options. FeP400 also performed efficiently under flowing conditions using low-range NH and TOC samples over 10 cycles, polishing not only 34.1 L of water with undetected NH, neutral pH, and extremely low TOC but also effectively recovering the NH uptake at an economical cost. Lastly, its environmentally friendly nature, which contains essential nutrients for plant growth, further enhances its recyclability after release. Thus, FeP400 is believed to offer a transformative, sustainable, and highly efficacious solution to the NHcontamination and critical ultrapure water issues that industries urgently address.