高盐条件下伊利石表面钚的吸附和氧化还原形态。
Sorption and redox speciation of plutonium at the illite surface under highly saline conditions.
机构信息
Institut für Nukleare Entsorgung, Karlsruhe Institute of Technology, P.O. Box 3640, D-76021 Karlsruhe, Germany; Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, F-35708 Rennes Cedex 7, France(1).
Institut für Nukleare Entsorgung, Karlsruhe Institute of Technology, P.O. Box 3640, D-76021 Karlsruhe, Germany; Institute for Transuranium Elements, European Commission, P.O. Box 2340, D-76125 Karlsruhe, Germany(1).
出版信息
J Colloid Interface Sci. 2017 Jan 1;485:59-64. doi: 10.1016/j.jcis.2016.09.013. Epub 2016 Sep 13.
Natural groundwater may contain high salt concentrations, such as those occurring at several potential deep geological nuclear waste repository sites. Actinide sorption to clays (e.g. illite) under saline conditions has, however, been rarely studied. Furthermore, both illite surface and ionic strength may affect redox speciation of actinides like plutonium. In the present study, Pu sorption to illite is investigated under anaerobic conditions for 3<pH (=-log [Formula: see text] )<10andm=1.0and3.2 molal (m). Results are compared with previous data for m=0.1m. According to redox potential measurements and based on Eu(III)-illite sorption data (taken as analogue of Pu(III)), the strong effect of m on overall Pu uptake observed for pH<6 is mainly attributed to the presence of Pu(III) and its competition with Na for ion exchange sites. For pH>6, overall Pu uptake is largely insensitive to m due to the prevalence of strongly adsorbed Pu(IV). By applying appropriate corrections to the activity coefficients of dissolved ions and using the 2-site protolysis non-electrostatic surface complexation and cation exchange (2 SPNE SC/CE) model, experimental data on Pu sorption to illite as a function of pH, Eh and m can be very well reproduced.
天然地下水可能含有高盐浓度，例如在几个潜在的深部地质核废料处置库场址中就存在这种情况。然而，在盐条件下，锕系元素对粘土（例如伊利石）的吸附作用研究甚少。此外，伊利石表面和离子强度都可能影响钚等锕系元素的氧化还原形态。本研究在厌氧条件下，针对 pH 值为 3<pH<10 且 m=1.0 和 3.2 摩尔（m）的条件下，研究了钚在伊利石上的吸附情况。并将结果与 m=0.1m 的先前数据进行了比较。根据氧化还原电位测量，并基于 Eu(III)-伊利石吸附数据（用作 Pu(III)的模拟物），在 pH<6 时观察到 m 对总 Pu 摄取量的强烈影响主要归因于 Pu(III)的存在及其与 Na 对离子交换位点的竞争。在 pH>6 时，由于强烈吸附的 Pu(IV)的存在，总 Pu 摄取量对 m 的影响不大。通过对溶解离子的活度系数进行适当校正，并使用 2 位质子化非静电表面络合和阳离子交换（2 SPNE SC/CE）模型，可以很好地再现 Pu 吸附到伊利石上随 pH、Eh 和 m 变化的实验数据。
Zotero 插件