Abstract: Cesium is easily soluble in water, and has a good migration rate and a low boiling point, making it difficult to dispose of safely. The safe disposal of radioactive cesium is an urgent problem to be solved. Current technologies used for cement fixation and solidification, and ion exchange have certain shortcomings in the treatment of cesium containing waste liquid, and further optimization is urgently needed. Pollucite belongs to the zeolite type molecular sieve, with a suitable pore size. Without damaging the structure of pollucite, radioactive cesium cannot diffuse out of it. Many studies have shown that it is one of the potential ultimate choices for disposing of radioactive cesium. In previous studies, pollucite needs to be synthesized at high temperatures above 1 000 ℃, which can cause the volatilization of cesium and increase the difficulty of tail gas treatment. This study used hydrothermal method to simulate the generation environment of molecular sieve zeolites in nature and achieved the synthesis of pollucite at lower temperatures. Through a 2 L/batch treatment device, the cesium containing waste liquid is treated, with a removal rate of over 99% for cesium in the wastewater. This study also tested the leaching resistance, thermal stability, and radiation resistance of cesium, confirming its strong stability and suitability as a radioactive disposal material.

Key words: pollucite, hydrothermal method, cesium removal, process validation