Catalytic reduction of pertechnetate (99TcO4-) in simulated alkaline nuclear wastes
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Pertechnetate ion (99TcO4-, 10-4 M) in alkaline solution is quantitatively reduced to hydrous TcO2 by thermolysis (65 °C, 4 days) in the presence of organic complexants and fission-product noble metals (RuCl3,
RhCl3, and PdCl2; 0.001 M). Over 99% reduction occurs in the presence of ethylenediaminetetraacetic acid (EDTA), hydroxyethyl(ethylenediaminetriacetic acid) (HEDTA), or glycolic acid valunit{0.050}{M}). Nitrilotriacetic acid (NTA), oxalic acid, and citric acid provide ≤ 2% reduction. Ruthenium, rhodium, and palladium chlorides also catalyze the reduction of TcO4- by hydrogen gas. The results are consistent with a two-step process of complexant degradation to generate H2, followed by catalytic reduction of pertechnetate to hydrous TcO2 or soluble technetium complexes. Catalytic reduction is a viable, non-radiolytic route to the formation of non-pertechnetate species of 99Tc in alkaline nuclear wastes, e.g., Hanford tank wastes.
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Articles in the same Issue
- Solubility and hydrolysis of tetravalent actinides
- Neptunium redox speciation
- Distribution coefficients of UO2(NO3)2 · 2TBP in supercritical fluid CO2 as determined by on-line time resolved laser induced fluorescence
- Interactions of Np(V) and U(VI) with dipicolinic acid
- Reactivity of 99mTc(V) ''3+1''mixed-ligand complexes towards glutathione
- Positron annihilation in hydrogen-doped alkali-metal fullerides
- The "age" of plutonium particles
- Catalytic reduction of pertechnetate (99TcO4-) in simulated alkaline nuclear wastes
Articles in the same Issue
- Solubility and hydrolysis of tetravalent actinides
- Neptunium redox speciation
- Distribution coefficients of UO2(NO3)2 · 2TBP in supercritical fluid CO2 as determined by on-line time resolved laser induced fluorescence
- Interactions of Np(V) and U(VI) with dipicolinic acid
- Reactivity of 99mTc(V) ''3+1''mixed-ligand complexes towards glutathione
- Positron annihilation in hydrogen-doped alkali-metal fullerides
- The "age" of plutonium particles
- Catalytic reduction of pertechnetate (99TcO4-) in simulated alkaline nuclear wastes
