To research the adsorption process of uranium from sea water by aluminium-activated carbon composite adsorbent (C-Al-OH), the authors examined the effects of temperature, pH and carbonate ion concentration of the solution upon the adsorption of uranium, using sodium chloride solution and natural sea water.
The continued mixing of the solution for the duration of two to four hours was required to attain the apparent equilibrium of adsorption. The adsorption velocity at an early stage and the uptake of uranium at the final stage showed an increase in proportion to a rise in the adsorption temperature. In the experiment of adsorption for which sodium chloride solution was used, the linear relationship between, the logarithm of the distribution coefficient (K_d) and the pH of the solution was recognized. The uptake of the uranium from the solution at the pH of 12 increased. as the carbonate ion concentration in the solution decreased. The uranyl ion in the natural sea water was assumed to be uranyl carbonate complex ion (UO₂(CO₃)₃^4-). As the result of the calculation conducted by using the formation constants for uranyl complexes in literature, it was. found that uranyl hydroxo complex ion (UO₂(OH)₃^-) increased in line with a decrease of the carbonate ion concentration in the solution.
The above results of the experiment suggested that the adsorption of uranium by the adsorbent.(C-Al-OH) was cationic adsorption or hydrolysis adsorption being related with the active proton on the surface of the adsorbent.

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中国天日塩の品質と塩田母液組成との関係を検討するため, 昭和50年5月中国塘沽塩田において採取した濃縮池かん水と結晶池母液30点および結晶池母液に対応する天日塩10点とを分析・検討して次の結果を得た.
1) 各段階の濃縮池かん水と結晶池母液の液組成をNa/Mgの値から検討すると, 原海水の値は8であるが, 第二蒸発池中段から6～4に減少し結晶池では3となった. このことから, 第三蒸発池以降結晶池までの間で母液が循環していることが推定された.
2) 今回採取した天日塩試料の分析値は, 前報の平均値と比較した結果, NaClは1.5%多く, 水分と不溶解分はそれぞれ1%と0.2%少なかった. またマグネシウムとカリウムはやや多く, カルシウムと硫酸イオンはやや少なかった.したがって, かなり良質なものであったといえる.
3) 結晶内部の不純物について同様に比較した結果, カリウムを除いて前報の20～50%程度であり上質な天日塩であった.
4) 計算した塩結晶の付着液マグネシウム濃度は, 採取時の結晶池母液マグネシウム濃度より大きいことから, この結晶は結晶成長時により濃縮された母液中におかれてこの液を包み込み, その後濃縮の進まないかん水が供給されたものと推定された.
5) 採取した10～20mmの大きさの天日塩結晶を4～5mm程度に粉砕後約80%溶解し, 結晶の外側と内側との不純物を比較した結果, 外側の量は内側にくらべてカリウムで4～6倍, マグネシウムで6～12倍であった. このことから, 不純物は, 大部分結晶の外側に付着していると推定された.
6) 天日塩結晶に含まれる総水分2.39/100gのうち, その11%(0.26g/100g) は液泡として結晶内部に, 30%(0.67g/100g) は単位結晶間に, 59%(1.37g/100g) は結晶表面に存在すると推定された.

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東京湾における流入汚染河川水の影響する地点を中心とした水質, 底質の分析, および底質の保温実験の結果, 硫酸塩還元細菌に関して以下のことが明らかとなった.
1) 流入する汚染河川水は, 密度差から上下によく混合されない状態で, 沿岸海域の表層部をかなり広く拡散する. そのため, COD, NH₄⁺-N, NO₂^--Nとも表層部のほうが大きい. おもに河口付近の底質で増殖した硫酸塩還元細菌が, 河川水により運ぼれてくるために, 河川水の直接流入する海域の表層部で海水中の菌体数がとくに多い.
2) 東京湾奥のような汚染海域においては, 海水中でも硫酸塩還元細菌が増殖する可能性がある. その場合, 菌体数には, 有機物濃度および温度が影響する.
3) この海域の硫酸塩還元細菌は, おもに淡水性培地に対しより強い還元活性を示したこと, およびとから, 淡水起源と考えられる.
4) 底質中では硫酸塩還元細菌が活発に増殖している. 底質中の菌体数に対して, 有機物濃度の影響はみられず, むしろ, 温度の影響 (夏季に増加し冬季に減少する傾向) がみられた.
5) 底質中の硫化物と有機物濃度にはよい相関があった.
6) 底質を37℃, pH7で嫌気状態に保持した場合, 硫化水素が新たに発生した. その発生速度は, 水素ガスを吹き込んだ場合, 窒素ガスの場合の20倍であった.

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Oka, one of the above-mentioned authors reported in his previous paper on the graphical calculations for isothermal evaporation of four kinds of ionic brines by using Jdnecke type triangular coordinated diagrams of 5-component system Na⁺, K⁺, Mg²⁺, Ca²⁺ Cl^--H₂O saturated with NaCl at 110°C, 70°C, 45°C. As the most practical result, it was found that the best NaCl yield of ionic brine could be obtained by doing the evaporation just upto the saturation point of KCl. The hot mother liquor separated from such concentrated slurry was saturated at the same time with NaCl and KCl. When it was cooled, therefore, salt crystals must have been depositted.
In the present paper, the authors again made graphical calculations as to how much water be evaporated by evaporation at 110°C under the best conditions, how much NaCl be obtained, and what kinds of salts come out by cooling the separated hot mother liquors to 25°C and how much of them be obtained. The phase diagrams of D'Ans type of 5-component system saturated with NaCl were used for these calculations, because the concentrations of the components could be read directly.
Only a part of the diagrams for the 5-component system which was requisite for the calculations was drawn on the common axes; namely, lines for the bivariant systems, NaCl-KCl-Carnallite-H₂O (SX), NaCl-Carnallite-Bischofite-H₂O (RY), and a monovariant system NaCl-KCl-H₂O (E) as shown in Tables 1 and 2, and Fig.-1.
By evaporation of ionic brine at 110°C, the mother liquor saturated with KCl must be on the triangle E₁S₁X₁. By cooling the mother liquor, the kind of salts to deposit can be determined by the position of point on the part of 25°Cdiagram. Such computations were done in Fig.-1, and the triangle E₁S₁X₁ was devided into three fields; namely, II, V and III, by two straight lines gh and ij. The mother liquor in field II deposited NaCl and KCl by being cooled to 25°C, and it lay on the triangle E₂S₂X₂. The hot mother liquor in field V deposited NaCl, and carnallite simultaneously by being cooled to 25°C, and the cold mother liquor lay on the line S₂X₂. And, the hot mother liquor in field III deposited NaCl and carnallite simultaneously, and the cold mother liquor lay on the quadrangle S₂X₂Y₂R₂.
When four ionic brines A, B, D and E (Table-5) were evaporated at 110°C to the saturation point of KCl, the mother liquors for A and B lay in field II, and those for D and E lay in field V. The graphical calculation for mother liquor A was shown in Fig.-2, and for D in Fig.-3.
For such calculations, the final concentrations of KCl, MgCl₂ and CaCl₂ could be read directly from the diagrams. But the concentration, of NaCl could not be read directly, and so it was interpolated with Fig.-4 on the assumption that the concentration of NaCl on a straight line changed linearly.
The results of these calculations were verified: The results of evaporations were compared with those in the previous paper, and the crystal depositions by cooling were verified with semi-quantitative experiments. The authors believe from these verifications that the method of calculations is a reliable one.

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温度を種々に変えて, 温度が限界電流密度に与える影響を検討した結果, 電気透析槽にスペーサーがない場合, 温度を種々に変えても, 筆者らが先に求めたEq.(1) から, 限界電流密度を推定できることがわかった.
また, 限界電流密度と温度の関係を便宜的に表わす式として, Eq.(3) を得た.

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Vol. 30 (1976) No. 2 p. 108
本誌第30巻第2号に掲載の“講座”加峯正美・住田哲雄著「計量法と量目管理について」の中に下記の誤りがありましたので, 訂正いたします.
修正箇所：本文 右側

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