Lyu Peng, Wang Guanghui, Cao Yelin, Wang Bing, Deng Nansheng
State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, China.
State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, China; School of Water Resources & Environmental Engineering, East China University of Technology, Nanchang, 330013, China.
Chemosphere. 2021 Aug;276:130116. doi: 10.1016/j.chemosphere.2021.130116. Epub 2021 Feb 26.
The decommissioning of uranium mill tailings (UMTs) is usually accompanied by uranium (U) contamination in soil, which poses a serious threat to human health and ecological safety. In this study, a novel phosphorus-modified bamboo biochar (PBC) cross-linked Mg-Al layered double-hydroxide (LDH) composite ("PBC@LDH") was successfully prepared by phosphate pre-impregnation and a hydrothermal method with Mg-Al LDH. Physicochemical analysis revealed that phosphorus-containing functional groups and Mg-Al LDH were grafted onto the pristine biochar (BC) matrix. Laboratory-scale incubation and column leaching experiments were performed on the prepared BC, PBC, and PBC@LDH. The results showed that, at a dosage of 10%, the PBC@LDH composite had a commendable ability to immobilize U in soil. After 40 days of incubation with the stabilizer, the more mobile U was converted into immobilized species. Furthermore, during a column leaching experiment with simulated acid rain, the cumulative loss and leaching efficiency of U were remarkably reduced by PBC@LDH treatment compared with the control, reaching 53% and 54%, respectively. Surface complexation, co-precipitation, and reduction described the adsorption and immobilization mechanisms. In conclusion, this research demonstrates that the PBC@LDH composite offers a potentially effective amendment for the remediation of U contaminated soil.
铀矿尾矿的退役通常伴随着土壤中的铀污染，这对人类健康和生态安全构成严重威胁。在本研究中，通过磷酸盐预浸渍和水热法，成功制备了一种新型的磷改性竹生物炭（PBC）交联Mg-Al层状双氢氧化物（LDH）复合材料（“PBC@LDH”）。物理化学分析表明，含磷官能团和Mg-Al LDH接枝到了原始生物炭（BC）基质上。对制备的BC、PBC和PBC@LDH进行了实验室规模的培养和柱淋滤实验。结果表明，在用量为10%时，PBC@LDH复合材料在土壤中固定铀的能力值得称赞。与稳定剂培养40天后，迁移性更强的铀转化为固定态。此外，在模拟酸雨的柱淋滤实验中，与对照相比，PBC@LDH处理显著降低了铀的累积损失和淋滤效率，分别达到53%和54%。表面络合、共沉淀和还原描述了吸附和固定机制。总之，本研究表明，PBC@LDH复合材料为修复铀污染土壤提供了一种潜在有效的改良剂。
