The adsorption of molybdenum (Mo) and vanadium (V) from sea water on hydrous titanium (IV) oxide (HTO) was investigated.HTO as an adsorbent was prepared from the precipitation of aqueous solution of titanium (IV) tetrachloride by hydrolysis with alkaline solution at various pHs. HTOs of different crystallinities from anatase to amorphous were obtained at different precipitating pHs. The anatase type of HTO which was precipitated at low pH of the solution showed a larger capacity of adsorption for Mo than the amorphous. The capacity of adsorption for Mo on HTO increased in proportion to the crystallinity of anatase, while the one for V slightly increased. The linear relationship between log Kd and pH was obtained for the adsorption of Mo on HTO with slope of -0.9 in the range of pH 7 to 10. The enthalpy changes for the adsorption of Mo on HTO were estimated to be -2.8 kcal mol-1.Kd for the adsorption of V on HTO showed a large and constant value in the pH 6 to 10 region including natural sea water. These differences in the pH dependency of the adsorptive properties between Mo and V on HTO were thought to be due to the difference in the adsorption mechanism for these elements, for Mo was considered to be due to an anion exchange mechanism. The adsorption isotherms for Mo and V on HTO showed the Freundlich's relationship, and the equilibrium adsorption capacities for Mo and V on HTO were measured to be 40μg g-1 and 240μg g-1, respectively.
Effect of the gas-liquid mixture flows on the electrical resistance in an electrodialyzer was studied by assuming that the flow in this dialyzer at the time of introducing the bubbles between membranes was two-dimensional flow, and by comparing the specific electrical conductance of the gas-liquid mixture flows,λB, with that of the liquid,λw.τB defined as a function,τB=(λW-λB)/λB, could be expressed as a function of ε which was a gas hold up, and the αBp/α which was the ratio of the projectional area of bubbles in the direction of current flow and the electrode area. Effect of the geometrical shape factorsof bubbles on τB could be clarified by experimentally evaluating the relation between ε and αBp/α. The results showed that τB could be expressed as a function ofεand d/l which was the ratio of the bubble diameter,d, and the gap between membranes,l, and that τB in the whirlpool flow pattern which was effective for the turbulence of liquid flow was expressed as only a function of ε and was the smallest when compared to that in other patterns, which was effective for the electrical resistance at less than 1% of the total dissolved salt concentration.
It is considered that total contents of nitrogen and phosphorus in sea water in inorganic and organic forms are nearly constant in the entire ocean owing to their longer residence time, and the concentration of inorganic and organic compounds can be expressed as a sum of a constant term (primary concentration) and a variable term (plus or minus). The constancy of the total concentration was proved by the chemical analysis using a dry combustion method with respect to nitrogen in sea water. In the upper layer from the surface to 1,000m, variation in concentration is caused mainly by organic production, while in deeper layer, by decomposition of organic matters. The primary concentration is defined as concentration when biological production and AOU (apParent oxygen utilization) are zero. Results of calculation using observed values of nitrate ion concentration (N) and AOU at 54 stations located from 65°S to 17°N along 100°W and 146°W in the Pacific showed that the relation between rates of change of nitrate ion concentration and AOU was 0.043, and the primary concentrations were 20.2μg atoms/l for nitrate ion and 28.0μg atoms/l for organic nitrogen. Therefore, the total concentration of nitrogen in sea water was 48.2μg atoms/l. Using these values nitrate ion concentration was calculated below 1,000m in wide areas of the Pacific. Results agreed well with the observations. The phosphorus relation between rates of change of phosphate ion (P) and AOU was 0.0029, and the primary concentrations were 1.58 and 1.90μg atoms/l for inorganic and organic phosphorus. The phosphate ion concentration was calculated in the deep layer, and the results coincided very well with the observations. It was theoretically made clear that N/P ratio in sea water was determined by difference between ratios of primary concentration (12.8) and ΔN/ΔP (15).N/P ratio near the surface was lower than12.8due to biological production, and higher in the deep up to 14. The results of calculation of N/P ratio from the surface to the bottom at different stations showed a good agreement with the observation.