Sustainable Strategy toward Industrial Net-Zero Discharge: Synergistic Valuable Metal Utilization and Fluoride Uptake from Wastewater

In this study, zirconium-smelting wastewater was utilized as the metal source to fabricate a novel composite material, Zr–Fe–Y-201, through the in situ deposition of hydrous metal oxides onto a strong-based anion exchanger (201 × 7). The resulting composite demonstrated excellent F – removal performance over a wide pH range of 2∼9. The adsorption process followed the Langmuir isotherm model and the pseudo-first-order (PFO) kinetic model, indicating a spontaneous and endothermic reaction. At 303 K, the Langmuir saturation adsorption capacity reached 40.58 mg/g. Zr–Fe–Y-201 exhibited superior F – removal efficiency to that of 201 × 7 in the presence of coexisting anions and organic acids. The adsorption mechanism was primarily governed by ligand exchange involving hydroxyl groups on hydrous metal oxides and electrostatic attraction contributed by the quaternary ammonium groups on 201 × 7 matrix. Dynamic adsorption experiments revealed that the Zr–Fe–Y-201 composite could treat 100 BV of simulated groundwater and 22 BV of realistic photovoltaic wastewater, demonstrating its promising potential for practical engineering applications. This study presents an innovative strategy for recovering valuable metals from wastewater while simultaneously producing an efficient adsorbent for advanced F – removal, thereby achieving a sustainable approach toward industrial net-zero wastewater discharge.