铀尾矿库区土壤-地下水系统中典型放射性核素的污染分布与迁移规律研究

水文地球化学 土壤-地下水 污染物迁移 铀尾矿 核素
刘媛媛 2016-01 项目
In the production of uranium mining and metallurgy, it produces a large amount of tailing ore and residual ore. The residual long life radioactive elements such as uranium, thorium, radium enter the soil and shallow groundwater easily and lead to the enrichment of radioactive elements in the food chain, eventually leading to the long-term potential radiation hazards to ecosystem. Therefore, it is necessary to carry out the research about pollution distribution and migration patterns of the typical radionuclide in soil and groundwater system. .This study will take a uranium tailings area in jiangxi province as example, The methods of data collection and field investigation, combined with the field measured, laboratory test and analysis is used to discuss pollution distribution and migration patterns. It will take the static analysis to research the relationship between factors such as temperature, Ph and nuclides adsorption performance in soil. With sequential chemical extraction method to study the nuclide distribution forms in the soil; a small neon water leaching of soil column experiment is used to research soil hydraulic properties and take the large soil column experiment to study nuclide migration behavior in the soil and groundwater system. .In addition, The basic statistics and geostatistics were used for analyzing the correlation between the content of uranium, thorium and radium isotopes obtained by cluster analysis method and the indicators about Ph, organic carbon in external environment, as well as distribution regularity in horizontal and vertical migration..The research results will provide certain theoretical and technical basis for repairing contaminated soil and groundwater of the China's uranium tailings.
铀矿冶生产中,产生了大量的尾矿砂与残矿。其中残余的铀、钍、镭等长寿命放射性元素很容易进入土壤和浅层地下水中,使放射性元素在食物链中富集,最终对生态系统产生潜在的、长久的辐射危害。因此,深入开展典型放射性核素在土壤-地下水系统中污染分布与迁移规律研究是必要的。本研究以江西某铀尾矿库区为对象,通过资料收集与野外勘察,结合场地实测、实验室测试与分析方法。采用静态法分析温度、Ph等因素对核素在土壤中吸附性能的影响,用序贯化学萃取法研究核素在土壤中的各种形态分布,用小型土柱的氖水淋洗实验研究土壤水力学性质,用大型土柱实验研究核素在土壤-地下水系统中的迁移行为。另外,以基础统计学、地统计学为基础,运用相关分析、聚类分析等方法获得铀、钍、镭等核素的含量与外界环境中Ph、有机碳等指标的相关性以及在横向、纵向的迁移分布规律。研究成果可为我国铀尾矿库放射性污染土壤和地下水修复提供一定的理论和技术依据。