Investigation of Mass Transfer Mechanism Associated with Water-Rock Reaction and Its Application to Resources and Environmental mental Problems

本研究取得的重要成果如下：(1)热液蚀变岩的分析研究阐明了稀土元素在热液蚀变过程中的地球化学行为。(2)基本金属(如铬等)和稀土元素污染土壤、河流沉积物和砂子的分析研究和提取及水-岩相互作用的实验研究阐明了贱金属和稀土元素的浓度和化学状态。(3)基于分析和热化学数据以及水-岩相互作用实验对地下水化学进行了解释。计算机模拟也被用于其解释。水-岩相互作用实验和模拟也应用于CO_2的地下封存，估算和阐明了含水层中的CO_2容量和地下CO_2的行为。(4)对沉积岩中的次生矿物(粘土矿物和碳酸盐)中的贱金属和稀土元素进行了分析，并考虑了控制这些元素浓度的因素(离子半径、电荷、电负性等)。考虑了从核废料中释放的放射性元素的延缓作用。考虑了防止基本金属元素从污染土壤中释放的方法。(5)开展了基于动力学-流体流耦合模型的模拟，用于解释地下水地球化学和估算地下水在山上的停留时间。富士地区。

Important results obtained by this study are summarized as follows.(1) Analytical study on hydrothermally altered rocks associated with hydrothermal are deposits ( kuroko deposits) clarified geochemical behavior of rare earth elements during the hydrothermal alteration.(2) Analytical study on base metals (i. e. Cr etc) and rare earth elements contaminated soils, river sediments and sands and experimental study on the extraction and water-rocks interaction clarified the concentrations and chemical states of base metal and rare earth elements.(3) Groundwater chemistry was interpreted based on analytical and thermo chemical data and water-rock interaction experiments. Computer simulation was also used for its interpretation. Water-rock interaction experiments and simulations were also applied to CO_2 underground sequestration and CO_2 capacity in aquifer and CO_2 behavior in underground were estimated and clarified.(4) Secondary minerals( clay minerals and carbonates) in sedimentary rocks were analyzed for base metals and rare earth elements and the factors controlling the concentrations of these elements ( ionic radii, charge, electronegativity etc) were considered. The retardation of radioactive elements released from nuclear waste was considered. The method preventing the release of base metal elements from contaminated soils was considered.(5) The simulation based on kinetics-fluid flow coupling model was carried out to interpret groundwater geochemistry and estimate residence time of groundwater in Mt. Fuji area.