Diffusion and advection with sorption of anions, cations and non-polar molecules in organo-clays at varying thermo-chemical conditions - validation by analytical methods and molecular simulation

在规划的高水平废物处置库（HLWR）的多屏障土工系统中阴离子的吸附以及在常规废物处置中非离子和有机污染物的吸附是最近研究的中心。在水生系统中，诸如79Se、99Tc、129I等持久性放射性核素以阴离子形式存在。越来越需要寻找对这类污染物具有高吸附能力的材料。对阻隔材料的具体要求是吸附剂在各种条件下的长期稳定性，如在100°C、变化的静水压力和竞争离子的存在下。有机粘土能够同时吸收大量的阳离子、阴离子和非极性分子，对某些离子有选择性。本项目旨在提高对有机粘土吸附和解吸过程的认识。此外，在不同的化学和热条件下，材料性能的改变将通过进行扩散和平流实验来确定。通过测定表面电荷和接触角来分析吸附和扩散的变化。有机粘土模型的分子模拟将与实验结果相一致，旨在理解和分析实验结果。该项目的计算部分将受益于德国合作伙伴与维也纳小组的合作，该小组在粘土矿物建模方面有着长期的经验。

The sorption of anions in geotechnical multibarrier systems of planned high level waste repositories (HLWR) and of non-ionic and organic pollutants in conventional waste disposals are in the center of recent research. In aquatic systems, persistent radionuclides such as 79Se, 99Tc, 129I exist in a form of anions. There is strongly increasing need to find materials with high sorption capacities for such pollutants. Specific requirements on barrier materials are long-term stability of adsorbent under various conditions such as T > 100°C, varying hydrostatic pressure, and the presence of competing ions. Organo-clays are capable to sorb high amounts of cations, anions and non-polar molecules simultaneously having selectivity for certain ions. This project is proposed to improve the understanding of sorption and desorption processes in organo-clays. Additionally, the modification of material properties under varying chemical and thermal conditions will be determined by performing diffusion and advection experiments. Changes by sorption and diffusion will be analyzed by determining surface charge and contact angles. Molecular simulations on models of organo-clays will be conducted in an accord with experiments with aim to understand and analyze experimental results. The computational part of the project will profit from the collaboration of German partner with the group in Vienna, which has a long standing experience in a modeling of clay minerals.