Study On Microwave-assisted Fenton Reagent Degradation Of Cation Resin And Cement Solidification

A large amount of radioactive waste liquid will be produced in the production process of the nuclear industry.Due to the presence of radionuclides,the radioactive waste liquid needs to be effectively treated and discharged or further disposed.The ion exchange process is used to treat medium and low-level radioactive waste liquids because of its high decontamination factor.Ion exchange resins with good stability are commonly used ion exchange materials.Ion exchange resins that adsorb radionuclides become spent ion exchange resins.Its disposal has become one of the difficulties facing the development of the nuclear industry.At present,in the international treatment of spent resin,the wet oxidation technology is used to degrade the resin before curing treatment.This study uses microwave-assisted Fenton wet oxidation technology to efficiently degrade the spent cation exchange resin and analyze the degradation products as well as cement solidification was studied.It was found that the microwave assisted Fenton technology could achieve the efficient degradation of resin.Under the microwave assisted action,the concentration of hydroxyl radical produced by Fenton reagent was much higher than that of ordinary Fenton reagent,and the strong oxidizing hydroxyl radical produced by Fenton reagent and the chemical bond between the resin could be rapidly degraded.At the same time,microwave heated the system rapidly to reach the ideal reaction conditions,reducing the surface binding energy of the resin,hydroxyl radical can quickly enter the resin to achieve internal and external degradation at the same time,improve the degradation efficiency.The effects of various conditions of microwave-assisted Fenton reagent method on degradation were studied and analyzed.Low microwave power,acidic conditions,and suitable catalyst and oxidant ratios could achieve efficient degradation of cation exchange resins.The effect of various experimental factors on the degradation rate was analyzed by response surface analysis.Optimized experimental conditions were obtained:15 g cation resin,microwave power 120 W,initial pH=1.37,0.02 mol·L^-1 FeSO₄ solution dosage 52.868 mL,the dosage of 30%H₂O₂ was 95.333 mL,and the COD removal rate at 60 minutes was 1.301g·L^-1.An apparent kinetic equation for microwave-assisted Fenton reagent to degrade cationic resin was established.The components of degradation products and the distribution of nuclide in the degradation process were studied.The main components of the degradation solution are inorganic salts and small organic molecules,and the main components of the gas are oxygen,carbon dioxide,carbon monoxide,sulfur dioxide,and the like.Nuclide distribution analysis showed that no nuclide was found in the gas,and the nuclide was mainly retained in the degradation solution.Based on the experimental research results,a microwave-assisted Fenton reagent degradation device was designed and established to achieve the integration of highly efficient resin degradation and volume reduction.A one-time treatment of 900 g of resin was achieved,and the volume of degradation solution was reduced by 50%in 30 minutes,and the COD value was 2.247 g·L^-1.The solidification of the acidic organic degradation solution produced by the degradation was studied.Through the analysis of physical and chemical properties such as the internal structure characterization,compressive strength,freeze-thaw resistance,and chemical leaching rate of the solidified body,it was shown that the pH of the degraded liquid has a greater effect on the performance of the solidified body Large,and the impact of organic components is small,so the pH of the degradation solution should be adjusted in engineering applications.Based on the microwave-assisted Fenton reagent method to degrade cationic resin,a systematic experimental study was conducted,the efficient degradation mechanism was analyzed,optimized experimental conditions were established,a complete set of integrated degradation and volume reduction devices was designed and established,and a small test was conducted.The degradation products were analyzed for composition and cement curing research.The results showed that the microwave-assisted Fenton reagent technology can be used as an engineering application technology for resin degradation treatment.