A test module plant of multistage flash (MSF) evaporator to desalt sea water was constructed in Oita for the purpose to obtain sufficient data in designing a 100,000m³/day plant. The research and development had been conducted as an activity in the 2nd phase of the national project on the “SEA WATER DESALTING AND BY-PRODUCT RECOVERY” which was completed in March, 1977. The test module plant was operated not to produce water, but to acquire precise data. From this standpoint, the data acquisition system played a significant part in the project. In advance, we had already experienced the process to deal with an acquisition system in the 3,000m³/day MSF evaporator which had been tested for three years until 1973 in the 1st phase of the project, and found two problems to be practiced. One is the highly precise temperature measurement of flashing brine throughout a long-term operation and the other is the computer system capable of dealing with multijobs.
This paper describes the following valuable experiences with the system.
(1) The absolute precision of temperature measurement was better than about 10 ppm as far as independently regarding to the A/D-converter by calibrating with a standard resistance.
(2) Calibration of each platinum resistance for temperature measurement within an absolute precision of 0.01°C resulted in accomplishing temperature measurement at an absolute precision of better than 0.1°C even after two years.
(3) The secular change of resistance in platinum sensor brought about the greatest effect on the absolute precision of temperature measurement.
(4) The precisely measured temperature distribution in flashing brine provided an advanced idea for determining chamber geometry of the evaporator.

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(1) 塩化ナトリウムと塩化カルシウムの混合水溶液中にhexa-dimethrine bromideを微量添加し, これを小型透析装置に供給し, 通電しながら陽イオン交換膜の2価イオン難透過処理を行なったところ, カルシウムイオンのナトリウムイオンに対する選択透過係数T^Ca_Naは大幅に低下した.
(2) 処理にともなって, 極間電圧が増加した.電圧上昇の第1の理由は, 陽イオン交換膜面に形成された処理剤層と陽イオン交換膜との境界領域で電解質イオン濃度が低下するためであり, 第2の理由は処理剤層の電気抵抗が増加するためである.
(3) 処理によって脱塩液はアルカリ性に, 濃縮液は酸性に変化した. pH変化の理由は, 処理剤層と陽イオン交換膜の境界領域で水分解が生じたためである.
(4) 処理した陽イオン交換膜の電気抵抗を塩化ナトリウムと塩化カルシウムの混合水溶液中で測定したところ, 大きな値が得られた. これは, 処理剤層が2価イオン (カルシウムイオン) 難透過性を示すので, 処理剤層の電気抵抗が増加したためである. 同一膜の塩化ナトリウム水溶液中で測定した電気抵抗は大きな値とならず, 処理剤層はナトリウムイオンの透過に対して大きな抵抗を示さないと思われた.
(5) 陽イオン交換膜に対する処理剤は, 陰イオン交換膜面に蓄積しない.

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We have been studing the extraction method of uranium from sea water by aluminium hydroxide and by the aluminium-activated carbon composite adsorbent.
The present study was undertaken to determine of heating effect on the uranium adsorptivity of the aluminium hydroxide and of the aluminium-activated carbon composite adsorbent.
Aluminium hydroxide, which was prepared by hydrolysis of aluminium chloride, showed high adsorptive capacity for uranium by heating at 250°C, but showed decrease of the capacity by heating at higher temperature than 250°C, and lost the capacity at higher themperature than 400°C.
In the case of the composite adsorbent, the unheated adsorbent showed the highest adsorptive capacity, and the adsorbent lost the capacity by heating at higher temperature than 250°C. The adsorptive capacity of the heated adsorbents at higher than 250°C for uranium were closely proportional to the alkaline consumption.

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