摘要
铀尾矿存在着残留的铀,在水流的作用下,会溶解出来,随着渗滤液的流动而在包气带与地下水中迁移,渗滤液中铀的赋存形态会影响着铀的迁移。本研究采用动态柱进行铀尾矿淋溶与渗滤液在黏土中迁移实验,采用PHREEQC软件模拟计算铀的赋存形态,分析铀的迁移。实验结果表明,淋滤液从尾矿中浸出的铀质量浓度很低,尾矿底部的黏土层对低质量浓度铀的吸附效率不高,而且尾矿渗滤液呈酸性,尾矿中的H+与SO_(2)-4极易随淋滤液的迁移而迁移,黏土对其吸附能力不强。铀在尾矿渗滤液和黏土穿透液中的形态主要有四种,其相对质量浓度顺序为UO_(2)F^(+)>UO_(2)SO4>UO_(2)+2>UO_(2)(SO_(4))^(2-)2,铀的赋存形态在黏土层迁移过程中不会发生明显变化,F-、SO_(2)-4是影响溶解态铀迁移的主要因素。该研究可以为铀尾矿地下水修复与铀土壤污染修复提供理论基础。
There is residual uranium in uranium tailings,which will dissolve out under the action of water flow,and migrate in the unsaturated zone and groundwater with the flow of leachate.The occurrence form of uranium in the leachate will affect the migration of urani-um.In this study,the leaching of uranium tailings and the transfer of leachate in clay were investigated by column experiments,and the occurrence forms of uranium were simu-lated using the PHREEQC software.The experimental results show that the concentration of uranium leached from the tailings by the leachate is very low,and the clay layer at the bottom of the tailings does not have a high adsorption efficiency for the low concentration of uranium;moreover,the tailings leachate is acidic,and the H+and SO_(2)-4 in the tailings eas-ily migrate with the leachate,and the clay does not have a strong capacity to adsorb them.There are four main forms of uranium in the tailings leachate and clay penetrating fluid and the relative order of content is UO_(2)F^(+)>UO_(2)SO_(4)>UO_(2)+2>UO_(2)(SO_(4))^(2-)2.The forms of ura-nium do not change significantly during the migration process through the clay layer and F-and SO_(2)-4 are the main controlling factors affecting the migration of uranium in the dissolved state.The research can provide a theoretical basis for uranium tailings groundwater reme-diation and uranium soil pollution remediation.
作者
赵艳梅
吕俊文
李凌鑫
ZHAO Yanmei;LYU Junwen;LI Lingxin(School of Resources Environment and Safety Engineering,University of South China,Hengyang,Hunan 421001,China;Hengyang Key Laboratory of Soil Contamination Control and Remediation,Hengyang,Hunan 421001,China)
出处
《南华大学学报（自然科学版）》
2024年第2期21-29,共9页
Journal of University of South China：Science and Technology
基金
科技部重大专项(2019YF(1907701))。
关键词
铀尾矿
渗滤液
铀的形态
黏土
uranium tailings
leachate
occurrence forms of the uranium
clay
