Tannic acid and trivalent iron modified Fe3O4 nanoparticles as a new adsorbent to remove uranium from wastewater

•The preparation of Fe3O4 nanoparticles modified by tannic acid and trivalent iron (TA-FeⅢ@Fe3O4).•The TA-FeⅢ@Fe3O4 was used for U(Ⅵ) adsorption. The properties of the TA-FeⅢ@Fe3O4 were analyzed.•The properties of the TA-FeⅢ@Fe3O4 were analyzed.•SEM, XPS and FTIR were adopted to explore adsorption mechanism.•Adsorbed TA-FeⅢ@Fe3O4 can be easily separated, regenerated and reused. This study reports the preparation and application of Fe3O4 nanoparticles modified by tannic acid and trivalent iron for U(Ⅵ) removal. The phenolic hydroxyl group on the tannic acid molecule can be complexed with U(Ⅵ), so as to achieve the goal of adsorping uranium from wastewater, and the maximum adsorption capacity of TA-FeIII@Fe3O4 can reach 98.2 mg/g. Through the research on pH, dosage, adsorption kinetics and adsorption thermodynamics indicted that it were excepting as a new green adsorbent for removing U(Ⅵ) from wastewater.