典型铀矿区包气带砂质黏土在不同流速下的水动力弥散规律研究  

Hydrodynamic Dispersion of Sandy Clay Invadose Zone of Typical Uranium Mining Area at Different Velocities

作　　者：王赵明 杨松 谢添 陈文杰 梁鹏亮 陈超[1] 石云峰[1] 张艾明[1] WANG Zhaoming;YANG Song;XIE Tian;CHEN Wenjie;LIANG Pengiang;CHEN Chao;SHI Yunfeng;ZHANG Aiming(China Institute for Radiation Protection,Taiyuan 030006,China)

机构地区：[1]中国辐射防护研究院核环境模拟与评价技术重点实验室,太原030006

出　　处：《核电子学与探测技术》2023年第5期975-984,共10页Nuclear Electronics & Detection Technology

摘　　要：铀化学性质活泼,兼具放射性和化学毒性,易发生活化、迁移与富集。铀矿退役后存在的污染物迁移扩散涉及范围广,各核素和其他重金属之间的相互关系复杂,长期影响环境质量和人体健康。水动力弥散是核素在土中迁移的重要形式,弥散度是污染物迁移模拟中最常用的参数。针对我国某典型铀矿区包气带砂质黏土,以3H溶液为示踪剂,进行不同流速下的土柱穿透试验,并运用对流-扩散方程拟合溶质穿透曲线得到弥散度,结果表明,随着流速增大,3H穿透曲线向左移动,且逐渐变陡,且土柱越早到达峰值浓度,峰值浓度也越高;水流速越慢,穿透曲线的后半段3H浓度下降越慢,穿透曲线的“拖尾”现象越严重;1倍、5倍、10倍最大年降雨量条件下,土柱的水动力弥散度DL分别为1.25、3.60、15.00 cm。Uranium has active chemical properties,both radioactive and chemical toxicity,and is prone to living,migration and enrichment.The migration and diffusion of pollutants after the decommissioning of uranium mines involve a wide range,and the interrelationship between various nuclides and other heavy metals is complex,which affects environmental quality and human health for a long time.Hydrodynamic dispersion is an important form of nuclide migration in soil,so dispersion is the most commonly used parameter in pollutant migration simulation.In this paper,aiming at sandy clay in vadose zone of a typical uranium mining area,°H solution is used as tracer to conduct soil column penetration tests at different flow velocities,and the hydrodynamic dispersion coefficient is obtained by fitting solute penetration curve with convection dffusion equation.The results show that as the flow velocity increases,the 3H penetration curve moves to the left,the penetration curve gradually becomes steeper,and the sooner the soil column reaches the peak concentration,the higher the peak concentration is;The slower the water flow rate is,the slower the"H concentration in the second half of the breakthrough curve decreases,and the more serious the"tailing"phenomenon of the breakthrough curve is;Under the conditions of 1,5 and 10 times of the maximum annual rainfall,the hydrodynamic dispersion coefficients D,of soil columns are 1.25,3.60 and 15.00 cm respectively.

关 键 词：铀矿区 包气带 水动力弥散 穿透曲线 

分 类 号：X591[环境科学与工程—环境工程]