Studies On Removal Of Trace-Amount Radionuclide From Low-Level Liquid Wastes By Weakly Basic Exchange Resin

By simulating low-level liquid waste (LLW) and by means of static and dynamic experiments, lots of research on the effect of trace-amount radionuclide removal by weakly basic anion exchange resins (WBAER) from LLW with alkali metals and alkaline-earth metals ions at high concentration, has been done. In this paper, the adsorption properties of radionuclide on resins were compared; the static isothermal adsorption curve and the static sorption capacity were measured. And by varying flow velocity and adding usual alkali metals and alkaline-earth metals ions (Ca²⁺, Mg²⁺) into raw water, the effects of trace-amount radionuclide removal by WBAER and strong-acid cation exchange resins (SACER) from LLW have been contrasted.The results show that: (1) when the concentration of radionuclide ions in influent water is very low, the effect of radionuclide removal by WBAER is much better than SACER. (2) under neutral or near-neutral conditions and low equilibrium concentration(<100μg/L), the static isothermal adsorption curve of trace-amount radionuclide ions (Sr²⁺ Co²⁺, Cs⁺) on WBAER is linear. (3) with alkali metals and alkaline-earth metals ions (Ca²⁺, Mg²⁺) in raw water, WBAER has better selectivity to radionuclide ions in LLW, however the selectivity of SACER is worse. In a word, with alkali metals and alkaline-earth metals ions (Ca²⁺, Mg²⁺) in raw water, WBAER has better selectivity to radionuclide ions in water, it can effectively remove trace-amount radionuclide from LLW.In addition, a series of analyses about theoretical principles of trace-amount radionuclide ions removal by WBAER from LLW with alkali metals and alkaline-earth metals at high concentration and regeneration of WBAER, have been analyzed. And factors, such as flow velocity, usual alkali metals and alkaline-earth metals ions (Ca²⁺, Mg²⁺) in raw water and the concentration of radionuclide ions in influent water, which can influence the effect of trace-amount radionuclide removal by WBAER from LLW have also been discussed from ion exchange kinetics.