岩洞型低中放废物处置库围岩对^(137)Cs的吸附性能研究  

Adsorption properties of surrounding rock for^(137)Cs in a cavern-type low and intermediate radioactive waste repository

作　　者：阳刚 林静若岚 杨雪颖 庹先国[1] 潘跃龙 刘羽 YANG Gang;LIN Jingruolan;YANG Xueying;TUO Xianguo;PAN Yuelong;LIU Yu(Chengdu University of Technology,Chengdu 610059,China;Southwest University of Science and Technology,Mianyang 621010,China;China Nuclear Power Engineering Co.,Ltd,Shenzhen 518000,China)

机构地区：[1]成都理工大学,成都610059 [2]西南科技大学,绵阳621010 [3]中广核工程有限公司,深圳518000

出　　处：《核技术》2022年第8期9-17,共9页Nuclear Techniques

基　　金：国家自然科学基金(No.41630646)资助。

摘　　要：结合我国广东阳江岩洞型低中放废物处置库的建设实际,以该废物处置库的围岩及拟处置的核素^(137)Cs为基础,研究了围岩对Cs的吸附性能。一系列表征分析显示:处置库围岩晶体结构良好,SiO含量最高;围岩表外为不规则的片状结构堆叠而成,片与片之间呈压实状态,表面拥有-OH、Si-O-Si、Si-O-Al、Si-O等基团。通过静态吸附试验,考察了时间、p H值、固液比、初始放射性活度浓度、不用离子等因素对吸附的影响,并对其吸附动力学及吸附等温模型进行了分析。结果显示:当固液比为5 g·L^(-1)、初始放射性活度为1114.5 Bq·L^(-1)时,吸附平衡时间为12 h,平衡吸附率为40.41%,平衡吸附量为90.07 Bq·g^(-1);吸附率随固液比而增大,随初始放射性活度的增大而减小;酸性条件下对吸附有抑制作用,中性及碱性条件下对吸附影响不大;不同离子均对处置库围岩吸附Cs有抑制作用,其中K+抑制作用最大。围岩对^(137)Cs的吸附更符合准二级动力学模型及Freundlich吸附等温模型。研究结果可为处置库的建设提供基础数据支持。[Background]At present,radioactive waste is treated by deep geological treatment.Caves-type repository as a geological repository near the ground,are more and more international and domestic concern due to its nuclear safety,low environmental pollution and good economy.A cavern-type low and intermediate radioactive waste repository is being constructed in Yangjiang area of Guangdong province,China,the surrounding rock of the waste repository will be the main dispose material of nuclide^(137)Cs.[Purpose]This study aims to investigate the adsorption performance of the surrounding rock of this cavern-type low and intermediate radioactive waste repository for^(137)Cs.[Methods]First of all,series of characterization analysis,such as X-ray Fluorescence(XRF),Scanning Electron Microscope(SEM),Transmission Electron Microscope(TEM),Brunauer-Emmett-Teller(BET),BarretJoyner-Halenda(BJH)were employed to observe crystal structure and content of the surrounding rock of the waste repository.Irregular sheet-like structures stacked,the sheets in a compacted state,and the surface groups such as-OH,Si-O-Si,Si-O-Al,Si-O,etc.were shown to have good crystal structure and the highest SiO2 composite content.Then,the effects of time,pH value,solid-liquid ratio,initial radioactive activity concentration,and ions on the adsorption were investigated through static adsorption experiments.Finally,the adsorption kinetics and adsorption isotherm models were analyzed.[Results]The results show that when the solid-liquid ratio is 5 g·L^(-1),the initial radioactivity is 1114.5 Bq·L^(-1),the adsorption equilibrium time is 12 h,the equilibrium adsorption rate is40.41%,and the equilibrium adsorption capacity is 90.07 Bq·g^(-1).The adsorption rate increases with the increase of the solid-liquid ratio,and decreases with the increase of the initial radioactivity.The adsorption is inhibited under acidic conditions,but has little effect under neutral and alkaline conditions.Different ions inhibit the adsorption ofCs on the surrounding rock of the reposit

关 键 词：岩洞型处置库 围岩 ^(137)Cs 吸附 

分 类 号：TL941[核科学技术—辐射防护及环境保护]