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

规划中的高放废物处置库(HLWR)岩土复合屏障系统对阴离子的吸附以及常规废物处理中非离子污染物和有机污染物的吸附是最近研究的中心。在水生体系中，持久性放射性核素如79Se、99Tc、129I以阴离子的形式存在。寻找对这类污染物具有高吸附能力的材料的需求日益强烈。对阻隔材料的特殊要求是在各种条件下，如T&gT；100°C、变化的静水压力和竞争离子的存在下，吸附剂的长期稳定性。有机粘土能够同时吸附大量的阳离子、阴离子和非极性分子，对某些离子具有选择性。这个项目是为了提高对有机粘土吸附和解吸过程的了解。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。将通过测定表面电荷和接触角来分析吸附和扩散的变化。对有机粘土模型进行分子模拟，使模拟结果与实验结果一致，以便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该集团在维也纳的合作，该集团在粘土矿物建模方面拥有长期经验。

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.