Through the course of this fundamental study on the collection of uranium in sea water, the authorconducted an extensive improvement in the separating and determining methods of uranium in seawater. Also, he made various studies on the collecting methods of uranium in sea water, chieflyemploying the adsorption method with titanic acid which was one of the most effective methods.
Chemical species of uranium in sea water were researched by the stability constants of suchcomponents of sea water as Na+, K+, Ca2+, Me+, SO42-, PO33-, HPO32-, CO32-, OH-, and UO22+. As the consequence, most of the dissolved uranium species were found to be UO2 (CO3) 34-.The adsorption mechanism of uranyl carbonate complex ion on titanic acid was presumed an anionexchange reaction. The adsorption of uranium was governed by the kind of titanic acid, thetemperature of sea water, the contacted volume of sea water and the concentration of uranium insea water.
In the preparation of titanic acid, the adsorption capacity of titanic acid prepared in homogeneousand acidic solution proved to be larger than those prepared in non-homogeneous and neutral solution.Warm sea water was more preferrable because the amount of uranium adsorption indicated anextreme increase at a high temperature. The adsorption capacity was estimated by the distributioncoefficient multiplied by the concentration of uranium in sea water.
Experimentally, the maximum value of the concentration of uranium in titanic acid amounted toU/Ti=1550μg/g, while the maximum adsorption capacity evaluated was U/Ti=4200μg/g. For thedesorption of uranium from titanic acid, the use use of hydrochloric acid was recommended as themost faultless method. In the conclusion of this study, the author presented some problems for future studies.
