Abstract: An adsorbent capable of adsorbing radioactive antimony, radioactive iodine and radioactive ruthenium, the adsorbent containing cerium(IV) hydroxide in a particle or granular form having a particle size of 250 ?m or more and 1200 ?m or less; and a treatment method of radioactive waste water containing radioactive antimony, radioactive iodine and radioactive ruthenium, the treatment method comprising passing the radioactive waste water containing radioactive antimony, radioactive iodine and radioactive ruthenium through an adsorption column packed with the adsorbent, to adsorb the radioactive antimony, radioactive iodine and radioactive ruthenium on the adsorbent, wherein the absorbent is packed to a height of 10 cm or more and 300 cm or less of the adsorption column, and wherein the radioactive waste water is passed through the adsorption column at a linear velocity (LV) of 1 m/h or more and 40 m/h or less and a space velocity (SV) of 200 h?1 or less.

Abstract: An adsorbent capable of adsorbing radioactive antimony, radioactive iodine and radioactive ruthenium, the adsorbent containing cerium(IV) hydroxide in a particle or granular form having a particle size of 250 ?m or more and 1200 ?m or less; and a treatment method of radioactive waste water containing radioactive antimony, radioactive iodine and radioactive ruthenium, the treatment method comprising passing the radioactive waste water containing radioactive antimony, radioactive iodine and radioactive ruthenium through an adsorption column packed with the adsorbent, to adsorb the radioactive antimony, radioactive iodine and radioactive ruthenium on the adsorbent, wherein the absorbent is packed to a height of 10 cm or more and 300 cm or less of the adsorption column, and wherein the radioactive waste water is passed through the adsorption column at a linear velocity (LV) of 1 m/h or more and 40 m/h or less and a space velocity (SV) of 200 h?1 or less.

Abstract: A treatment method of radioactive waste water containing radioactive cesium and radioactive strontium, comprising passing the radioactive waste water containing radioactive cesium and radioactive strontium through an adsorption column packed with an adsorbent for cesium and strontium, to adsorb the radioactive cesium and radioactive strontium on the adsorbent, wherein the adsorbent for cesium or strontium comprises a crystalline silicotitanate having a crystallite diameter of 60 ? or more and having a half width of 0.9° or less of the diffraction peak in the lattice plane (100), the crystalline silicotitanate represented by the general formula: A4Ti4Si3O16.nH2O.

Abstract: Provided is an adsorbent for removal of iodide ions and iodate ions, which exhibits excellent adsorption performance of iodide ions and iodate ions. An adsorbent according to the present invention comprises cerium(IV) hydroxide and a poorly soluble silver compound. It is preferable that the content of cerium(IV) hydroxide is 50% by mass or more and 99% by mass or less, and the content of the poorly soluble silver compound is 1% by mass or more and 50% by mass or less. It is also preferable that the poorly soluble silver compound is at least one selected from silver zeolite, silver phosphate, silver chloride, and silver carbonate.

Abstract: The invention provides an industrially advantageous method for producing a crystalline silicotitanate having high adsorption/removal capabilities for cesium and strontium in seawater. The method includes a first step of mixing a silicic acid source, a sodium compound, titanium tetrachloride, and water to prepare a mixed gel and a second step of hydrothermal reaction of the mixed gel prepared in the first step to produce crystalline silicotitanate of formula: Na4Ti4Si3O16.nH2O (wherein n represents 0 to 8). In the first step, the silicic acid source, sodium compound, and titanium tetrachloride are mixed in such a mixing ratio that the resulting mixed gel may have a Ti to Si molar ratio, Ti/Si, of 1.2 to 1.5 and an Na2O to SiO2 molar ratio, Na2O/SiO2, of 0.7 to 2.5.

Abstract: A method for producing a nonatitanate of an alkali metal, the method having: a first step for reacting an alkali metal hydroxide with titanium tetrachloride and producing Ti(OH)4; a second step for mixing the resulting Ti(OH)4 and an alkali metal hydroxide; and a third step for heating the mixture obtained in the second step, the alkali metal hydroxide being used so that the A/Ti molar ratio (A represents an alkali metal element) falls within a range of 1.0-5.0 in the second step, wherein a nonatitanate of an alkali metal can be produced economically.