摘要
为了解U、Sr在极低放废物预选场址土壤中的吸附行为，分别以238U和90Sr溶液为示踪剂，用静态吸附法测定吸附分配系数，并研究pH、共存离子、胶体等条件的影响。研究结果表明：场址土壤对U、Sr的最大分配系数分别为11 300和723 mL/g；U、Sr的吸附均符合Fruendlich等温吸附方程；当pH为4～8时，铀的吸附分配比最大，而锶的分配系数最小；Ca^2＋和Mg^2＋的引入均能降低土壤对U、Sr的吸附，且对Sr的影响大于对铀的影响；在CO3^2－和C2O4^2－浓度很低时，能显著降低U的吸附分配系数；而CO3^2－的存在能够增大其对Sr的吸附；Fe（OH）3胶体的存在使U、Sr的吸附分配系数显著降低；腐殖酸（HA）的存在使土壤对U的吸附减弱，但能够增大Sr在土壤中的吸附。
The adsorption behaviors of uranium and strontium were investigated on soil of very low-level radioactive waste （VLLW） in a preelection site by the static experimental method. The effects of the various experimental conditions such as pH, coexist iron and colloid on the adsorption were investigated with the ^238U and ^90Sr as indicator respectively. The maximum adsorption distribution coefficient （Kd） of U and Sr on the site＇s soil are 11 300 and 723 mL/g, respectively. The concentration relationship in aqueous solutions and the adsorption capacities of U and Sr can be described by the Freundlich adsorption equation. The Ka of U is maximum when the pH is 4-8, however, the Ko of Sr is minimal. It is also noted that the Kd of U and Sr drops obviously when the solution contains Ca^2＋ or Mg^2＋ , even the influence on Sr is more than U. The Kd of U reduces remarkably when adding in CO3^2- or C2O4^2- , but the Ka of Sr increases. The ferric hydroxide colloid would make the Ka of U and Sr drop. The Kd of U decreases while the Ka of Sr increases when the humic acid exists in solution.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2009年第5期412-420,共9页
Atomic Energy Science and Technology
基金
核设施退役及放射性废物治理专项
关键词
极低放废物
土壤
吸附
U
SR
腐殖酸
very low-level radioactive waste
soil
adsorption
U
Sr
humic acid
