Posted by The remediation of uranium-contaminated soil remains a persistent challenge in the field of environmental restoration. Herein, a novel β-cyclodextrin-modified thermally oxidized biochar (CDTB) was synthesized and systematically evaluated for its long-term stability and underlying mechanisms in remediating uranium-contaminated soil. The results demonstrated that CDTB treatment significantly reduced the proportion of exchangeable and carbonate-bound states, while increasing the residual states. According to toxicity characteristic leaching procedure (TCLP) tests, the uranium leaching concentration in the CDTB-treated group was only 0.0297 mg/L, substantially lower than that of the control group (0.271 mg/L). Moreover, after 20 rounds of wet-dry or freeze-thaw cycles, the TCLP-extractable uranium concentration remained unchanged, confirming the long-term stability of the immobilized uranium. Application of CDTB also reshaped the soil microbial community, restored bacterial populations inhibited by uranium toxicity, and enhanced ecological functionality. A random forest model identified soil available phosphorus (AP) as the most critical factor influencing uranium immobilization. The immobilization mechanism and durability of CDTB were attributed to synergistic effects involving physical adsorption, chemical reduction, precipitation, and microbial involvement.
SAP: sludge and rice husks; toxicity characteristic leaching procedure; TB thermally oxidized biochar
Xinyu Zhao, Yanjie Lv, Lijie Chen, Huinan Wu, Yalan Liu, Jing Sun, Zhongran Dai (2026) β-cyclodextrin-modified thermally oxidized biochar for efficient remediation of uranium-contaminated soil. Journal of Environmental Chemical Engineering 14, 121310. https://doi.org/10.1016/j.jece.2026.121310.