2018 年 67 巻 10 号 p. 898-903
The adsorption capacity of cesium and strontium in the aqueous solution of rice hull charcoal was examined. Rice husk which was carbonized at various temperatures was added to each of cesium aqueous solution and strontium aqueous solution and stirred. As a result, rice hull charcoal carbonized at 400°C adsorbed the cesium. Rice hull charcoal carbonized at 800°C adsorbed the strontium. From this result, it was considered that the adsorption mechanism of rice hull charcoal cesium and strontium are different. From the analysis results by FTIR and Boehm method, charcoal carbonized at 400°C had acidic functional group. There was a tendency that the pH of the rice hull charcoal carbonized at high temperature became higher. It is considered to be due to precipitation of inorganic substances such as potassium on the surface of rice hull charcoal. As a result of pore distribution measurement, it was found that many mesopores were formed in rice hull charcoal carbonized at 800°C. It is assumed that cesium adsorbs primarily on acidic functional groups on the surface of rice hull charcoal, strontium undergoes ion exchange with potassium, or adsorbs to mesopores.