Research On Selective Adsorption Materials And Capture And Separation Process Of Iodine Nuclides In Wastewater

In addition to radioactive iodine,which is one of the most important nuclides in the wastewater of nuclear facilities in normal operation and in case of accidents,the potential environmental and ecological hazards of iodine nuclides in uranium ore processing wastewater,spent fuel reprocessing wastewater,wastewater from radioactive treatment in hospitals,and radioactive wastewater from research processes in military and scientific research units cannot be ignored.The development of efficient capture and separation technology for iodine nuclides in wastewater is of great significance for the sustainable development of China’s nuclear industry.In this thesis,a new composite functional adsorbent material is designed and prepared for the main presence of iodine nucleophile in wastewater,and then a monolithic capture and separation system is designed on the basis of the adsorption mechanism,constitutive relationship and adsorption kinetics.The main research elements and results are as follows.1.Innovative Ag-induced dynamic chemical plating technology to achieve effective regulation of the crystalline state,particle size and morphology of copper species on filamentous zeolite carriers;through various characterization means,the nucleation mechanism of Cu₂O/Ag particles formed by heterogeneous nucleation of copper species on Ag particles and epitaxial growth along the surface of filamentous zeolite molecular sieve（MOR）was elucidated.2.The maximum adsorption capacity for iodide ions in wastewater was 275mg/g through the synergistic effect of chemisorption and physical adsorption;for liquid iodine（I^-/IO₃^-）,the removal rates of iodide ions and iodate could reach For liquid iodine（I^-/IO₃^-）,the removal rates of iodide and iodate were above 99.1%and80%respectively.The adsorption mechanism of iodide ions by Cu（I）was proposed,demonstrating that chemisorption is the controlling step of the adsorption process.3.A new composite functional material（Dynamic Cu/Ag-MOR）was loaded onto a monolithic inert carrier（honeycomb ceramic cordierite）,a high throughput microchannel reactor was constructed,the process design of a gas-liquid-solid three-phase simulated iodine nucleophile adsorption and separation system was completed,and the equipment design of the reactor and gas-liquid separator was simulated by Aspen software.The wastewater treatment capacity can reach 1000 kg/h in continuous operation,and the adsorbent has an iodine adsorption capacity of 0.25g/g,with adsorption selectivity and efficiency close to 100%.In addition,the project has carried out environmental impact and safety analysis of the pilot process.