[in Japanese]

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The authors carried out a study on the adsorption of uranium in sea water using titananic acid as adsorbent. The titanic acid was prepared by neutralization method with alkali solution, by homogeneous precipitation with urea or ammonium acetate, and by heating hydrolysis using titanic sulfate as starting material.
The results of the study indireted that the amount of uranium adsorption in sea water was effected by conditions under which the titanic acid was prepared, as mentioned below:
1. By whichever method titanic acid may be prepared, the amount of uranium adsorption shows an increase if tha homogenity and acidity of the solution are maintained.
2. In case titanic acid is prepared by neutralization method or by homogeneous precipitation method with ammonium acetate, it became curdy, thereby yielding a greater amount of uranium adsorption.
The following were the conclutions obtained from the study in regard to the amount of uranium adsorption in sea water:
1. The amount of uranium adsorption shows an increase as the temperature of sea water rises and the concentration of uranium contained in sea water increases.
2. The amount of uranium adsorption decreases due to an increase in salinity and co-existence of phosphate, fluoride and copper, but this effect is so small that can be neglected in sea water.
3. The amount of uranium adsorption in natural sea water shows a decrease of 20% as compared with that in artificial sea water.
The authors carried out a study on the adsorption of uranium in sea water using titananic acid as adsorbent. The titanic acid was prepared by neutralization method with alkali solution, by homogeneous precipitation with urea or ammonium acetate, and by heating hydrolysis using titanic sulfate as starting material.
The results of the study indireted that the amount of uranium adsorption in sea water was effected by conditions under which the titanic acid was prepared, as mentioned below:
1. By whichever method titanic acid may be prepared, the amount of uranium adsorption shows an increase if tha homogenity and acidity of the solution are maintained.
2. In case titanic acid is prepared by neutralization method or by homogeneous precipitation method with ammonium acetate, it became curdy, thereby yielding a greater amount of uranium adsorption.
The following were the conclutions obtained from the study in regard to the amount of uranium adsorption in sea water:
1. The amount of uranium adsorption shows an increase as the temperature of sea water rises and the concentration of uranium contained in sea water increases.
2. The amount of uranium adsorption decreases due to an increase in salinity and co-existence of phosphate, fluoride and copper, but this effect is so small that can be neglected in sea water.
3. The amount of uranium adsorption in natural sea water shows a decrease of 20% as compared with that in artificial sea water.

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In this paper, the authors manufactured for trial a casting apparatus to improve the atability of the characteristics of experimental reverse oεmosis membranes of Loeb's type (formamide system).
The casting apparatus mainly consisted of a doctor knife, a hopper, a shifter of a motor-operated knife and an apparatus for taking out a glass plate, and it was set in a container kept in constant atmospheric conditions. The size of the membrane which could be made by this apparatus was one meter in length and 20 centi-meters in width. By this apparatus, no pin-holes were made in the membrane because the casting solution of the membrane flowed in the form of film on the glass plate at constant velocity, thereby bringing in no air.
The rate of salt rejection and the coefficient of water flux of the membranes prepared by this apparatus under those conditions that the casting atmosphere was aceton gas and the evaporating temperature was 5°C, was 98.2±0.5%, 0.72±0.06 1/m² hr. atm., while those of the membranes prepared by the existing hand-operated apparatus were 96.3±2.4%, 0.89±0.31 l/m² hr. atm.
As the result, this apparatus proved to be superior to the existing apparatus in the stability of membrane characteristics.

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