Study On The Treatment Of Strontium Containing Simulated Liquid Radioactive Waste By In-situ Electrochemical Synthesis Of Manganese Oxide And Ferromanganese Oxide

Manganese oxide and ferromanganese composite oxides are strong adsorbent,both of them have important application value in waste liquid treatment.Through the study of three aspects:the process optimization,the effect of water quality and the preliminary mechanism,to decide the feasibility of the electrochemical in situ synthesis of manganese oxide method and electrochemical in situ ferromanganese compound oxide method can treat simulated radioactive waste liquid in nuclear power plant properly,providing a technical reference for the treatment of radioactive waste liquid in the nuclear power plant.The experimental results are as follows:(1)The study of Sr2+ radioactive waste solution with manganese oxide method in simulated nuclear power plant showed that when the concentration of Sr2+ was 5mg/L,the residual Sr2+ concentration in the effluent was 0.264mg/L under the optimum process conditions,and the removal rate of Sr2+ was 94.72%.In addition,when the concentration of boric acid in the wastewater was 0?3000mg/L,the manganese oxide method still had a better removal effect on Sr2+,and the removal rate of Sr2+ is above 94%.(2)The preliminary mechanism of the removal of Sr2+ by manganese oxide method showed that the whole process accorded with the zero order kinetics,indicating that the removal rate of Sr2+ was not related to the concentration of Sr2+.Through on-line monitoring system ORP change and system pH and color change,it was found that electrolysis,generation and adsorption occurred at the same time during the whole electrolysis process,which confirms that the reaction was zero order kinetics.XRD analysis showed that the precipitated product was Mn3O4.The surface of SEM was found to be loose and porous with rough surface,indicating that the four oxidized three Mn precipitates had good adsorption effect.(3)The study on the treatment of Sr2+ radioactive waste liquid containing Sr2+ in the simulated nuclear power plant showed that when the concentration of Sr2+ was 5mg/L,the residual Sr2+ concentration in the effluent was 0.201mg/L,and the removal rate of Sr2+ was 95.99%.In addition,when the concentration of boric acid in the wastewater was in 0-3000mg/L,and the manganese oxide method still had a better removal effect on Sr2+,and the removal rate of Sr2+ was above 95%.(4)The mechanism of the removal of Sr2+ by ferromanganese compound oxide method was similar to the mechanism of removing Sr2+ by manganese oxide method:the whole electrolysis process also conformed to the zero order kinetics.After analyzing the change of ORP on line monitoring system and the change of pH and color of the system,it was concluded that three processes of electrolysis,generation and adsorption occur at the same time,which confirms that the reaction was zero order kinetics.XRD analysis of products showed that the precipitated products were Mn3O4 and Fe3O4.The surface of SEM was found to be loose and porous with rough surface,indicating that the precipitates had good adsorption effect.(5)Through the comparison of the two methods,it is found that the two methods have their own advantages and can be used for the treatment of radioactive waste water Sr2+ in nuclear power plants.