场址地下水特征因子对铀锶吸附的影响研究  

Research of groundwater characteristics factors of the site to adsorption of uranium and strontium

作　　者：谢云[1] 石正坤[1] 吴涛[1] 张东[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《化学研究与应用》2012年第11期1685-1690,共6页Chemical Research and Application

基　　金：核设施退役及放射性废物治理专项项目(4610-ZJEHTY-0801)资助

摘　　要：为了考察某放射性废物填埋场土壤对待填埋的核素铀锶的阻滞性能,对该填埋场土壤及地下水进行取样分析,根据测量的地下水特性参数,在静态条件下,考察了填埋场地下水主要的阴离子SO42-、CO32和阳离子Ca2、Mg2+、Na+、K+对核素铀锶吸附影响,同时结合填埋场地下水的pH和Eh,考察了溶液pH值对核素的吸附影响;结果表明:当pH在2～3之间时,铀的吸附量突然增大,pH在在4～8之间,铀的吸附量明显变化,在pH>10,吸附量又出现明显减小;当pH<6和pH>8后,锶的迁移分配系数(Kd值)明显的增大,而pH在6～8时,Kd值没有明显的变化;阴离子CO32-能明显的增加锶在土壤中的吸附,直接表现为Kd值的明显增大,Kd值增加103数量级;阴离子SO42-、CO32-、C2O42-对铀的吸附的影响表现非常明显,随着离子浓度的增加,几种阴离子明显降低了铀在土壤中的吸附,表现为Kd值大大降低,降低的系数在103数量级;阳离子对锶吸附的影响,Ca2+和Mg2+的影响比Na+要强,Ca2+和Mg2+离子浓度在很小的时候就能明显的降低锶的吸附;阳离子对铀吸附的影响,当Ca2+和Mg2+的浓度较低时对铀的吸附影响不大,当Ca2+达浓度大于1280.0μg·L-1,Kd值出现了较为明显的减小。In order to investigate the blocking performance of a radioactive waste landfill of uranium and strontium nuclides, the landfill field soil and groundwater were sampled and analysised, based on characteristics factors of the site of landfill parameters, under static conditions, the effects of the landfill the groundwater of the most abundant anion SO4^2-, the CO3^2- and cation of Ca^2＋ and Mg^2＋ and Na＋, K＋ radionuelide uranium strontium adsorption, combined with the landfill groundwater pH and Eh, investigated the influence of solution pH on radionuclide adsorption; the results showed that： a sudden increase of the adsorption of uranium when the pH is between 2 and 3 ,while between 4 to 8 ,the adsorption of uranium did not change significantly,the adsorption of uranium in the pH over 10 significant decreased ;when the pH value of less than 6 and more than 8, the distribution coeffleient of strontium signifi- cantly increased, the pH value was between 6 to 8, the partition coefficient did not change significantly; the C032- significantly in- creased the adsorption of strontium, expressed as a significant increased of the partition coefficient, increased of 10^3 orders of magni- tude ; the anionic SO4^2-, CO3^2. C2O4^2-affected the adsorption of uranium, with the increase of ion concentration, significantly reduced the adsorption of uranium,and expressed as reducing the coefficient is 103 orders of magnitude;caution of Ca^2＋ and Mg^2＋ influenced the adsorption of strontium more stronger than Na＋ ;eat ions on adsorption of uranium, when the low concentration of Ca^2＋ and Mg^2＋ had little effect on the adsorption of uranium,while Ca^2＋ up to concentrations of greater than 1250μg· L^-1 ,the partition coefficient decreased.

关 键 词：PH 离子 铀 锶 吸附 

分 类 号：O653[理学—分析化学]