| Tributylphosphate(TBP) is often used as the extractive solvent in the PUREX process. Repeated use of this solvent leads to its degradation on account of chemical and radiolytic attack. It should be treated as a waste form. In this thesis, we try to disposal the spent TBP solvent by two methods: hydrolyzation and mediated electrochemical oxidation. Those are the main work of the experiment:1,TBP was hydolyzed in an alkaline circumstance. Gas chromatography was used to test TBP hydrolyzing rate. The results indicated that TBP hydrolyzing rate could be nearly 100% in a 12.5M NaOH solution with the temperature between 95℃and 105℃. Solution of the hydrolysate was solidified and the compressive strength of the test block with 40% cement ratio could reach 12MPa after 28-day conservation.2,An Ag-mediated electrochemical oxidation(MEO) system was established to destruct spent TBP solvent. The system was in an H electrobath and use the Ti-PbO2 electrode. Test of TOC changes during the reaction time showed that TBP was first decomposed to several kinds of small substance which could dissolve in the water. It was also found the velocity during the oxidation process could get fast when the temperature is 50℃, besides the nitric acid concentration and the current density was 8M, 1A/cm2, respectively. The current efficiency achieved its highest point during the first 20min which could get 101.61%.3,Oxalic acid was decomposed in the MEO system. It was found this reaction was a first-order reaction. The reaction rate constant was calculated to be 7.1×10-3,8.7×10-3, 9.7×10-3 and 10.9×10-3min-1 when the temperature was 30, 40, 50 and 60℃. The activation energy according to the reaction-rate theory was calculated to be 11.4 kJ/mol.
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