摘要
为探究浸矿作用下稀土矿区土壤中重金属铊的释放规律及生物炭对铊的钝化修复机制,选取赣南某稀土矿区污染土壤为研究对象,通过静态浸泡与动态淋溶试验,结合动力学模型和扫描电镜(SEM)结果进行研究。试验结果表明,静态条件下,酸性浸矿剂和酸雨浸泡液中铊的质量浓度分别是中性雨水的27.75和1.55倍;动态条件下分别为21.71和1.31倍。酸性离子对土壤中重金属铊的释放具有促进作用,并使土壤中的铊从残渣态转化为活动态。动力学模型拟合结果表明,研究区重金属铊的淋出释放更符合修正的Elovich方程,表明铊在土壤中的释放不是单一的扩散过程,而是多个过程共同作用的结果。向土壤中添加生物炭后,铊的释放量降低了34%,土壤中的铊由活动态转化为残渣态。SEM结果表明生物炭的添加能降低土壤的侵蚀程度并增加多孔结构,有效阻滞土壤中铊的迁移释放。该研究结果可为稀土矿区铊污染土壤的修复提供理论参考。
To investigate the release patterns of heavy metal thallium(Tl)in soil from rare earth mining areas under leaching conditions and the stabilization mechanism of biochar for Tl,contaminated soil from a rare earth mine in southern Jiangxi was selected as the study subject.Static soaking and dynamic leaching experiments,combined with kinetic models and SEM analysis,were conducted.Experimental results showed that,under static conditions,the mass concentration of Tl in acidic leaching agents and acid rain was 27.75 and 1.55 times higher,respectively,than that in neutral rainwater.Under dynamic conditions,the corresponding values were 21.71 and 1.31 times higher.Acidic ions promoted the release of heavy metal Tl from soil,facilitating the transformation of Tl from a residual to an active state.Kinetic model fitting results indicated that the leaching release of Tl in the study area aligns more closely with the modified Elovich equation,suggesting that Tl release in soil was not a simple diffusion process but rather the result of multiple interacting mechanisms.After the addition of biochar,Tl release decreased by 34%,with Tl in the soil converting from an active state to a residual state.SEM analysis revealed that biochar addition reduces soil erosion and enhances its porous structure,effectively inhibiting the migration and release of Tl in soil.These findings provide theoretical support for the remediation of Tl-contaminated soil in rare earth mining areas.
作者
张沁宁
张强
叶义生
朱红霞
许模
陈雨
ZHANG Qinning;ZHANG Qiang;YE Yisheng;ZHU Hongxia;XU Mo;CHEN Yu(College of Environmental and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Geological Hazard Prevention and Control and Geological Environmental Protection,Chengdu University of Science and Technology,Chengdu 610059,China;Hydrogeological Brigade of Jiangxi Provincial Geological Bureau,Nanchang 410119,China)
出处
《环境工程学报》
北大核心
2025年第9期2247-2256,共10页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(41472275)
江西省地质局生态修复公益资助项目(2024STXF04)
四川省自然科学基金青年资助项目(2024NSFSC0848)。
关键词
稀土矿
铊
释放特征
生物炭钝化
动力学模型
rare earth mine
thallium(Tl)
release characteristics
biochar stabilization
kinetic model
