Np在Np-水-膨润土平衡体系中的形态及价态分布  

Speciation and Valence of Np in Balanced System of Np-groundwater-bentonite

作　　者：姜涛[1] 龙浩骑[1] 王波[1] 包良进[1] 周舵[1] 

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《原子能科学技术》2016年第2期242-246,共5页Atomic Energy Science and Technology

摘　　要：采用批式法和溶剂萃取法,研究了Np在Np-水-膨润土平衡体系中的形态及价态分布以及pH值对形态及价态分布的影响。结果表明:在Np-水-膨润土平衡体系中,水相中的Np全部为Np(Ⅴ),固相中的Np为Np(Ⅳ)、Np(Ⅴ);pH=8~9时,随着pH值的升高,固相中Np的比例升高,pH>9时,固相中Np的比例降低;随着CO3_^(2-)浓度的升高,固相中Np的比例降低。PHREEQCI计算结果表明:pH<9时,Np在水相中的主要形态为NpO^+_2,pH>9时NpO_2OH逐渐成为Np在水相中的主要形态;在高CO_3^(2-)浓度条件下,NpO_2(CO_3)_2^(3-)、NpO_2(CO_3)^(5-)_3是Np在水相中的主要形态;pH值对Np在水相和固相中的价态分布无影响。The speciation and valence distributions and effect of pH on the speciation and valence distributions of Np in the balanced system of Np-groundwater-bentonite were studied by batch experiments and solvent extraction methods. The results indicate that the valence of Np in groundwater is penta-valent state, and tetra- and penta-valent states were obtained on bentonite. With the increase of pH, the percentage of Np（V） in bentonite increases at first and then decreases at phi9. With the increase of CO~ , the percentage of Np（ V ） in bentonite decreases. The calculation results of PHREEQCI show that NpO＋ is the main speciation of Np at pH〈9, and NpO2OH at pHi9. NpO2（CO3）23- and NpO2 （CO3）35- are the main speciations of Np at high concentration CO32-- solution. The valence of Np is not affected by pH.

关 键 词：NP 膨润土 形态 价态 

分 类 号：O614.352[理学—无机化学]