Granulated hydrous titanium oxide (HTO) has been evaluated as the most popular and the most excellent adsorbent for the extraction of uranium from seawater. But, its adsorption velocity has so far been published fragmentarily and to a limited extent. Therefore, the effects of bed condition have been scarcely studied in the earlier feasibility studies. First, this paper describes a report on the adsorption rate of granulated hydrous titanium oxide which was prepared by using a large scale aparatus for the first time in Japan. The parameters of adsorption rate in an adsorption bed were particle size, temperature of seawater, space velocity and concentration of uranium in seawater. The empirical formula on uranium uptake was shown with Bangham's formula and above parameters. C=14t0.845 (0.6/d')(Co'/0.0033)0.73(0.0235φ+0.41)(0.6Sv0.282). Second, these empirical formulas were applied to the estimation of outline of the adsorption bed in a fluidizing adsorption system by using multi-layer type, and an example of calculation was shown as 1,000 ton-U of annual uptake. The expansion ratio in the fluidizing bed was estimated by Max Leva's fomulas. The results were shown as the quantity of seawater, the number of pumps, the flow-rate in bed, uranium uptake, the thickness of bed, the interval of layer, the number of layer, the breadth of bed and the total length of facilities. These results show that the plant size will be smaller than the earlier estimations.
The ion exchange method was used for separating uranium from the eluate (0.5 N Na2CO3-0.5 NNaHCO3) that was obtained in the extraction process of uranium from natural sea water by using the titanium-activated carbon composite adsorbent. Uranium in the eluate containing 3mg/l uranium was adsorbed by ion exchange resin (Amberlite IRA-400), and was eluted with the eluant (5% NaCl-0.5% Na2CO3). The concentration ratio of uranium in the final concentrated-eluate became more than 20 times. The eluting solution to the adsorbent and the eluant to the resin could be repeatedly used in the desorption-ion exchange process. Sodium carbonate was consumed at the desorption step, and sodium bicarbonate was consumed at the ion exchange step. The concentration ratio of uranium was found to decrease as chloride ion in the eluate increased.
An experimental study has been made on effect of injection of nuclei by means of electrolysis of water on the spray flash evaporation occurring in a superheated water jet ejected through a single circular tube nozzle into a low pressure vapor zone for various electrolytic currents, nozzle diameters, liquid flow rates, liquid temperatures and superheats. The artificial nucleation was found to have a pronounced effect on the enhancement of the spray flash evaporation, thereby reducing the non-equilibrium temperature difference, even in the case of lower superheats.
Culture experiments using a diatom,Phaeodactylum tricornutum, were conducted to make clear the significance of influence of physico-chemical elements, such as light intensity and nutrient concentration, on the variations of organic composition of pariculate matters in the sea. The alga was cultured under four or five levels of light intensity in two series of condition of nutrient concentration, of which in series-1 inorganic nutrients were added only at the beginning of culture, while in series-2 they were added not only at the beginning but also occasionally added to keep them rich during the experiment. Masurements of photosynthetic activity of the culture and determinations of organic constituents of algal cells were intermittently carried out during the experiments. The results obtained are summarized as follows: 1) When the alga is cultured under the condition of low light intensity-low nutrient concentration (series-1 experiment), photosynthetic activity under low light intensity increases with an increase of culture period. Contents of chlorophyll a, proteinous amino acid and reserved carbohydrate are also observed to increase. 2) Under the condition of high light intensity-low nutrient concentration (series-1 experiment), the contents of chlorophyll a and proteinous amino acid decrease, but those of lipid and carbohydrate are observedto show a little increase. 3) Under the condition of high nutrient concentration (series-2 experiment), the light intensities give little difference to the variations of organic composition and photo-synthetic activity, in contrast to the preservation of high contents of proteinous amino acid under any light intensities. It is, therefore, evident that the significant influence of light intensity on the variations of organic composition of the alga is remarkable under the condition of low nutrient concentration.
A micro amount of copper contained in sea water, brine and common salt was determined by atomic absorption spectrophotometry in conjunction with extraction technique. Copper formed a complex with 5-bromo-salicylaldoxime (5-Br-SA), and was extracted into chloroform. The extract was decomposed with nitric acid-perchloric acid mixture, and then dissolved with 0.1 N hydrochloric acid. This resulting solution was sprayed into an acetylene-air flame. To find the optimum condition for the extraction of copper, the effect of pH, concentration of 5-Br-SA, shaking time, and diverse ions in the aqueous phase were examined. Less than 10μg of copper was quantitatively extracted into 10ml of 0.02M 5-Br-SA chloroform solution from aqueous solution at pH4.0, by shaking for 10 min. When a known amount of copper was added to the sea water samples, the copper was recovered satisfactorily. Some samples of sea water, brine and common salt were analized.