Elution control of radioactive cesium in MSWI fly ash using water repellent treatment

摘要

Radioactive cesium found in municipal solid waste incineration (MSWI) fly ash can be easily eluted through contact withenvironmentally sourced water, such as rainwater. Dissolution suppression treatment of radioactive cesium, such as throughcement solidification or geopolymer solidification, has been previously studied. Treatment through solidification requiresthe addition of a fixation agent, which results in an increase in the volume of fly ash following solidification. It is likely thatthe level of security at the landfill site will be high. In an attempt to simply suppress the elution of water-soluble radioactivecesium from MSWI fly ash without an increase in volume, we examined a water-repellent treatment method using four typesof water repellents. Our results indicate that when the incinerated fly ash is impregnated and mixed with a commerciallyavailable water repellent, such as a silane-based oligomer, an alkyl alkoxysilane compound, or a fatty acid, it is possible tosuppress the elution of radioactive cesium without a corresponding increase in fly ash volume.