Examination of a Water Washing Method for Radioactive Cesium in Municipal Solid Waste Incineration Fly Ash and a Separation-concentration Method for Washing Water

We examined the amount of radioactive cesium eluted into water by the Ministry of the Environment Notification No. 13 Test and the tank leaching test for the municipal solid waste incineration (MSWI) fly ash of 8000 Bq kg−1 or less that can be landfilled. From MSWI fly ash obtained by the two types of dissolution tests, we considered that more than 60 % of the radioactive cesium contained in the incineration fly ash attaches to water-soluble compounds or exists as a water-soluble compound. Treating MSWI fly ash as innocuous is a just issue, and water cleaning treatment was selected as a pretreatment considering, the elution of radioactive cesium from the incineration fly ash buried in the disposal site. From the results of the water washing test by repeated elution treatment and continuous elution treatment, elution was the most practical method for 36 hours continuously. We attempted to separate and concentrate radioactive cesium using three types of solid-phase disks: RAD disk, activated carbon filter paper, and Prussian blue non-woven fabric. RAD disk has a high recovery rate as a method for separating and concentrating radioactive cesium in a cleaning solution obtained by washing fly ash from municipal waste incineration with water.