Development of the removal system of toxic metal ions for the reduction of environmental load

本项目的目的是开发有毒金属离子去除系统，以减少环境负荷。2006-2007年间，以二氧化钛和碳酸钾为原料，采用助熔剂(钼酸钾)法制备了离子交换材料(四钛酸钾纤维)。在考察了四钛酸钾的物理性质后，采用盐酸洗涤的方法将其转化为水合四氢酸二氢化钾纤维。采用氢型钛酸酯作为碱金属基团、碱土金属基团和过渡金属基团的离子交换剂。这些金属离子具有较高的离子交换能力。2007年和2008年，对这些金属离子(碱金属离子群：锂离子、钠离子、钾离子、铷离子、铯离子)进行了分离。碱土金属离子群：镁离子、钙离子、锶离子、钡离子。采用柱法检测过渡金属离子群(铜离子、镍离子、锌离子)对这些金属离子的分离能力。属于同一组的两个金属离子之间的分离系数很高，将该方法应用于有毒金属离子的去除系统，以减少环境负荷，从而将该方法应用于高放废物中铯和锶离子的分离，使有毒的长寿命放射性废物与处理前相比有所减少。最后，有毒金属离子的分离可以与其他材料分离。

The purpose of this project is the development of the removal system of toxic metal ions for the reduction of environmental load. The synthesis of the ion exchange material (potassium tetratitanate fiber) was tried by flux (potassium molybdate) method using titanium dioxide and potassium carbonate between 2006 and 2007. After the investigation of physical characters of the potassium tetratitanate, this materials was changed to dihydrogen tetratitanate hydrate fibers by washing hydrochloric acid. The hydrogen type titanate was used to the ion exchanger for the three metal groups, such as alkali metal group, alkaline earth metal group, and transition metal group. These metals had high ion exchange ability by batch wise method.In 2007 and 2008, the separation of these group metal ions (alkali metal ion group: lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions. Alkaline earth metal ion group: magnesium ions, calcium ions, strontium ions, barium ions. Transition metal ion group: copper ions, nickel ions, zinc ions) were examined by column method to check the ability for the separation of these metal ions. The separation factor between two metal ions which belong to the same groups is very high and this method will be used to the removal system of toxic metal ions for the reduction of environmental load.From these results, this method will be applied for the separation of cesium and strontium ions in high level radioactive waste, and the toxic long life radioactive waste can be decrease compare than those before the treatment. Finally, the separation of toxic metal ions can be separate from other materials.