Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical car...Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.展开更多
铀纯化过程中会产生大量放射性废水,这些废水的处理在当下的环保要求下显得格外重要,而去除废水中有机物又是铀纯化废水处理中至关重要的一环。本文探究了电催化氧化法对铀纯化混合废水中有机物的去除效果。实验结果表明,电催化氧化法...铀纯化过程中会产生大量放射性废水,这些废水的处理在当下的环保要求下显得格外重要,而去除废水中有机物又是铀纯化废水处理中至关重要的一环。本文探究了电催化氧化法对铀纯化混合废水中有机物的去除效果。实验结果表明,电催化氧化法可以降低铀纯化废水95.6%的COD值,证明了电催化氧化法对铀纯化废水中的有机物具有较高的去除能力。通过探究不同实验条件下的电催化氧化效果,进而得到去除混合废水中有机物的最佳工艺参数,即在废水pH值为1、电流18 A(电流密度225 A/m^(2))的条件下,仅需240 min COD降低率可达95.3%。展开更多
Hydriding properties of uranium alloys have been studied to search for new hydrogen storage materials to be applied to hydrogen energy systems. Application of uranium-base hydrogen storage materials can be expected to...Hydriding properties of uranium alloys have been studied to search for new hydrogen storage materials to be applied to hydrogen energy systems. Application of uranium-base hydrogen storage materials can be expected to alleviate the risk, as well as to reduce the cost incurred by globally-stored large amounts of depleted uranium left after uranium enrichment. Various uranium alloys have been examined in terms of hydrogen absorptiondesorption properties, among which UNi Al intermetallic compound showed promising characteristics, such as lower absorption-desorption temperatures and better anti-powdering strength. First principle calculation has been carried out on UNi Al hydride to predict the change of crystal structure and the lattice constant with increasing hydrogen content, which showed this calculation to be promising in predicting candidates for good hydrogen absorbers.展开更多
文摘Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.
文摘铀纯化过程中会产生大量放射性废水,这些废水的处理在当下的环保要求下显得格外重要,而去除废水中有机物又是铀纯化废水处理中至关重要的一环。本文探究了电催化氧化法对铀纯化混合废水中有机物的去除效果。实验结果表明,电催化氧化法可以降低铀纯化废水95.6%的COD值,证明了电催化氧化法对铀纯化废水中的有机物具有较高的去除能力。通过探究不同实验条件下的电催化氧化效果,进而得到去除混合废水中有机物的最佳工艺参数,即在废水pH值为1、电流18 A(电流密度225 A/m^(2))的条件下,仅需240 min COD降低率可达95.3%。
基金Supported by Grants-in-Aid for Scientific Research(No.25420903)from the Ministry of Education,Culture,Sports,Science and Technology of Japan and Japan Industrial Location Center
文摘Hydriding properties of uranium alloys have been studied to search for new hydrogen storage materials to be applied to hydrogen energy systems. Application of uranium-base hydrogen storage materials can be expected to alleviate the risk, as well as to reduce the cost incurred by globally-stored large amounts of depleted uranium left after uranium enrichment. Various uranium alloys have been examined in terms of hydrogen absorptiondesorption properties, among which UNi Al intermetallic compound showed promising characteristics, such as lower absorption-desorption temperatures and better anti-powdering strength. First principle calculation has been carried out on UNi Al hydride to predict the change of crystal structure and the lattice constant with increasing hydrogen content, which showed this calculation to be promising in predicting candidates for good hydrogen absorbers.
