Am(Ⅲ)与腐殖酸配位行为的研究  

COMPLEX FORMATION OF AMERICIUM(Ⅲ) WITH HUMIC ACID

作　　者：章英杰[1] 赵欣[1] 魏连生 林漳基[1] 

机构地区：[1]中国原子能科学研究院放射化学研究所

出　　处：《核化学与放射化学》1998年第3期152-157,共6页Journal of Nuclear and Radiochemistry

摘　　要：采用萃取法研究了不同ｐＨ值的０．１ｍｏｌ／ｋｇＮａＣｌＯ４溶液中，Ａｍ（Ⅲ）与腐殖酸的配位行为。实验结果表明，Ａｍ（Ⅲ）－腐殖酸配合物的累积稳定常数与溶液ｐＨ值有关，配位比为１∶２。不同ｐＨ值条件下，Ａｍ（Ⅲ）与腐殖酸配合物的累积稳定常数为：ｌｇβ１＝６．５６±０．０５，ｌｇβ２＝１０．７７±０．１３（ｐＨ＝４．０）；ｌｇβ１＝７．９４±０．１１，ｌｇβ２＝１１．８０±０．２１（ｐＨ＝５．０）；ｌｇβ１＝１０．７４±０．２８，ｌｇβ２＝１２．８８±０．４９（ｐＨ＝６．０）；ｌｇβ１＝１２．８５±０．３０，ｌｇβ２＝１４．８０±０．６２（ｐＨ＝７．０）；ｌｇβ１＝１４．８８±０．４８，ｌｇβ２＝１５．６５±０．６９（ｐＨ＝８．０）；ｐＨ值的变化与Ａｍ（Ⅲ）－腐殖酸配合物累积稳定常数间的关系为：ｌｇβ１＝２．１６（±０．９８）ｐＨ－２．３４（±０．９３），ｌｇβ２＝１．２８（±１．０４）ｐＨ＋５．５２（±１．２１）。The presence of humic substances in natural waters will modify the migration behavior of actinides in the goesphere due to the strong reaction properties of these ligands with actinides.Therefore,the possible reactions of humic acid with actinides have been studied widely in recent years.The complex formation of Am(Ⅲ) with humic acid is studied with solvent extraction technique.The experiments are performed in the pH range from 4.0 to 8.0 in 0.1 mol/kg NaClO 4 solution at ambient temperature.Experimental results show that the complex formation constants of Am(Ⅲ) with humic acid are varied with the variation of pH value in solution. 1∶2 complex is obtained in the experiments and the complex formation constants determined at each pH are:lg β 1=6.56±0.05,lg β 2=10.77±0.31 at pH=4.0. lg β 1=7.94±0.11,lg β 2=11.80±0.21 at pH=5.0. lg β 1=10.74±0.28,lg β 2=12.88±0.49 at pH=6.0. lg β 1=12.85±0.30,lg β 2=14.80±0.62 at pH=7.0. lg β 1=14.88±0.48,lg β 2=15.65±0.69 at pH=8.0,respectively. The dependence of the complex formation constant on pH is:lg β 1=2.16(±0.98)pH-2.34(±0.93),lg β 2=1.28(±1.04)pH+5.52(±1.21),respectively.

关 键 词：^241Am(Ⅲ) 腐殖酸 萃取法 配合物 HDEHP 稳定常数 

分 类 号：O614.354[理学—无机化学]