A Study On High Efficient Degradation Of Simulated Radioactive Waste Resin By Mediated Electrochemical Oxidation

The efficient degradation of radioactive waste resins has been of intriguing focus due to its intractable treatment.As a treatment technology for organic liquid wastes,medicated electrochemical oxidation process(MEO)is characterized by excellent degradation efficiency,mild reaction condition and simple operation process.However,in view of the condition of mass transfer and the properties of wastes,there are several issues needed to be lucubrated further,including the behavior and mechanism of degradation towards organic solid wastes.In this dissertation,medicated electrochemical oxidation was utilized to treat simulated radioactive waste resin with the strong oxidizing transition metal ions Ag(II)and/or Ce(IV)as medium.The degradation process of resins was explored,the treatment parameters were optimized,the degradation mechanism was analyzed and the effect ofcoexisting Ag(II)and Ce(IV)in one system was also investigated.The highly efficient degradation of resin was realized both in Ag/MEO and Ce/MEO systems.synergistic effects of Ag/Ce,HNO3 and electric current were observed,and the resins,degradation was attributed to the strong oxidative metal ions of high valence.In the experiments,the degradation rate of D001 reached 82.7 % in the system of Ag/MEO with current efficiency 29.08 % and energy consumption 0.047 kW·h/g.In the Ce/MEO system,the degradation rate reached 95 % and the current efficiency and energy consumption was29 % and 0.076 kW·h/g respectively.Both Ag/MEO and Ce/MEO carried out more than 5times,indicating the MEO systems had good ability of reuse.The results of SEM and FTIR exhibited that the resin degradation was the process with layer-by-layer decomposition and stripping of its organic skeleton and functional groups.Meanwhile,the TOC results indicated that the skeleton of resin converted to liquid,then to CO2 and H2 O gradually.The degradation rate of resin in Ag/MEO and Ce/MEO system was 78.5 % and 88.73 %,respectively.Compared with the Ag/MEO or Ce/MEO systems,the MEO system with Ce and Ag revealed higher resin degradation rate.When c(Ag)=0.02 mol/L,c(Ce): c(Ag)=10:1,the degradation rate of resin reached over 95 %,which was 11.56 % higher than system ofCe/MEO.In addition,by contrast with system of Ag/MEO,the consumption of Ag and HNO3 both slashed.c(Ag)was reduced from 0.2 mol/L to 0.02 mol/L and c(HNO3)was lowered from 7 mol/L to 3 mol/L.The results of this dissertation provided theory basis for solid organic waste treatment by MEO and technique support to radioactive waste resin degradation,which exhibited significant application value in the field of radioactive waste treatment.