Uranium-containing wastewater poses a major threat to human health because of its toxicity and radioactivity. To address this issue, tea waste-derived porous biochar supporting the Fe–Mn bimetallic composite (FMBC) was fabricated using impregnation-pyrolysis and applied for U(VI) removal from aqueous solution. Batch experiments and characterization analysis were performed to investigate the adsorption properties and interaction mechanisms. Results showed that FMBC exhibit a maximum U(VI) removal capacity of 510.8 mg/g at pH = 5, T = 303 k, and t = 25 min. The kinetic and isotherm date fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model, respectively, indicating that uranium adsorption is dominated by chemical adsorption on FMBC. FTIR and XPS analyses further confirmed that the U(VI) adsorption mechanism by FMBC was attributed to surface complexation, π–π bonding, and reduction processes. In addition, the Cationic competitive adsorption experiment further highlighted the excellent selective performance of FMBC for U(VI) removal from aqueous solutions, which is important in radionuclides' pollution treatment.

含铀废水因其毒性和放射性而对人类健康构成重大威胁。为了解决这个问题，使用浸渍热解法制备了支撑 Fe-Mn 双金属复合材料 (FMBC) 的茶渣衍生多孔生物炭，并应用于从水溶液中去除 U(VI)。进行批量实验和表征分析以研究吸附性质和相互作用机制。结果表明，在 pH = 5、T = 303 k 和 t = 25 分钟时，FMBC 的最大 U(VI) 去除能力为 510.8 mg/g。动力学和等温线数据分别与拟二级动力学模型和朗缪尔等温线模型拟合良好，表明铀吸附以 FMBC 上的化学吸附为主。FTIR 和 XPS 分析进一步证实，FMBC 的 U(VI) 吸附机制归因于表面络合、π-π 键合和还原过程。此外，阳离子竞争吸附实验进一步突出了FMBC从水溶液中去除U（VI）的优异选择性，这在放射性核素污染处理中具有重要意义。