广东省伴生放射性固体废物中的铀在红壤中的吸附迁移  

Adsorption and migration of uranium from Guangdong associated radioactive solid wastetored soil

作　　者：朱志如 陈柏迪 陈志东[1] 邓飞[1] 王家玥[1] ZHU Zhiru;CHEN Baidi;CHEN Zhidong;DENG Fei;WANG Jiayue(Guangdong Environment Radiation Monitoring Centre,Guangzhou 510300,China)

机构地区：[1]广东省环境辐射监测中心,广州510300

出　　处：《核技术》2021年第2期59-65,共7页Nuclear Techniques

基　　金：广东省生态环境厅项目《广东省伴生放射性固体废物处置技术方案研究》资助。

摘　　要：对几种典型伴生放射性固体废物中的铀在广东红壤中的吸附迁移规律进行了研究,并考察了广东红壤对硝酸铀酰的吸附作用。实验结果表明:在实验柱的天然雨水淋滤实验中,离子型酸溶渣、独居石铀钍渣和钽铌矿酸溶渣中的铀淋出率分别为41.1%、0.015%、97.8%;废物中的铀在红壤中迁移与铀的存在形态有关,易溶于水的形态(如磷铀矿)更易在红壤中迁移,溶解性越大,迁移性越强;硝酸铀酰在红壤中的吸附等温线符合线性方程,吸附机理以分配作用为主,但分配系数Kd较低,红壤对硝酸铀酰的吸附能力较弱。为了降低铀的浸出与迁移,应将伴生放射性固体废物的pH提高,将铀转化为难溶形态。[Background]The associated radioactivity solid waste(ARSW)is one kind of slight uranium mine with high activity of radioactive nuclides 238U and 232Th.There are few reports about the migration of uranium from ARSW in the literature.There are abundant radioactive mines in Guangdong province.Therefore,it is of great significance to study the adsorption and migration behavior of uranium from ARSW in Guangdong environment.[Purpose]This study aims to investigate the adsorption and migration behavior of uranium in red soil in Guangdong province,hence provide technical support and reference for the treatment of ARSW.[Methods]Firstly,the associated radioactive solid wastes were studied by column leaching experiment in 14 cm columns with natural rainwater lasted for 100 days.And the uranium concentrations migrated into red soil from ARSW were measured.Secondly,the batch dynamic and static adsorption experiments of uranium in red soil were performanced with uranyl nitrate.[Results]The experimental results show that the uranium leaching rate of ionic acid solid waste,monazite waste and tantalum niobium acid solid waste are 41.1%,0.015%and 97.8%respectively in natural rain water column leaching experiments.The migration of uranium in red soil is related to the existence of uranium.The water-soluble uranium(e.g.,phosphoruranylite)is easier to migrate in red soil and increases with the increase of solubility.The adsorption isotherm of uranyl nitrate in red soil conforms to linear equation with a low partition coefficient Kd and a weak adsorption capacity of the red soilabout uranyl nitrate.[Conclusions]In order to reduce the leaching rate and motility of uranium,the pH of ARSW should be raised to convert the uranium into insoluble form.

关 键 词：伴生放射性固体废物 铀 红壤 吸附迁移 

分 类 号：TL94[核科学技术—辐射防护及环境保护]