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Volume 39, Issue 1
Displaying 1-7 of 7 articles from this issue
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Tatsuya YAMAMOTO, Hisao TAKASE, Fumio FUKUOKA1985 Volume 39 Issue 1 Pages 3-18
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThe recovery cost of uranium from seawater by the deposited slurry method has been estimated on the basis of laboratory scale experiments, theoretical computations and available data.The extent of adsorption and the sea depth were decided by the rate of adsorption of uranium on the adsorbents in the sea in consideration of the combined effect of the liquid side resistance and intraparticle diffusion.
The optimization concerning the loss of adsorbents in the sea and the installations for collecting the uranium rich deposited slurry on the sea bottom was discussed with the direct search method for nonlinear problems.
The cost for the recovery of sodium bicarbonate used for the elution of uranium from adsorbents was obtained by small scale experiments using an electrodialyzer.An intermittent reversal of the electric current enables the recovery of eluant from the slurry.
The costs of the centrifugation and thickening of the desalination of the slurry were discussed.The cost of the ion exchange membrane method for the secondary condensation of uranium was estimated by experiments concerning the adsorption and elution of uranium.
The total recovery costs of uranium were calculated with various economical restrictions.View full abstractDownload PDF (10856K) -
Kenkichi IZUMI, Toshio SAWA, Akira YAMADA1985 Volume 39 Issue 1 Pages 19-26
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSScale prevention is one of the most important problems in a distillation-type desalination plant. Alkaline scale consists of calcium carbonate and magnesium hydroxide. Formation of the alkaline scale is related to the chemical equilibrium of the carbonates in the brine and pH of the brine. So the pH control with decarbonation by acid injection is effective to prevent the formation of the alkaline scale.
Material balance of the carbonates in the brine in a multi-stage flash evaporator is calculated on the basis of the dissociative equilibrium of the carbonates. In the multi-stage flash evaporator, the brine is circulated in the condensers of the evaporating stages, the brine heater and the flash chambers. In the condensers and the brine heater, the carbonates in the brine are reduced by the formation of calcium carbonate scale, and in the flash chamber, both the dispersion of carbon dioxide and the formation of scale are considered to reduce the carbonates.
Scale prevention tests on the pH control method were carried out by using a 100m3/d, 10-stage flash evaporator. From the comparison of the experimental data on the behavior of the carbonates to the calculation values, indicated a good agreement between them. So the appropriateness of the calculation method has been made clear.View full abstractDownload PDF (4841K) -
Shigeroku YAMAGUCHI, Katsuya UESUGI1985 Volume 39 Issue 1 Pages 27-31
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSTrace amounts of copper and iron in sea water and common salt were determined by atomicabsorption spectrophotometry in conjunction with solvent extraction technique. Both metals reacted with 5-chloro-salicylaldoxime (5-CL·ESA) to form complexes which could be extracted into chloroform and then adversely extracted with hydrochloric acid into aqueous phase. The resulted solution was sprayed into an acetylene-air flame. The effect of pH, amount of 5-CL·ESA, shaking time on the extraction of metals were examined. Good recoveries of metals added to artificial sea water and sea water samples were demonstrated. Coefficients of variation obtained were 1.5 for copper and 2.8% for iron.View full abstractDownload PDF (3131K) -
Noriaki NAKAZAWA, Takeshi SAKO, Kenzaburo OBATA, Teiji OKUBO, Toshikat ...1985 Volume 39 Issue 1 Pages 32-36
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSFundamental researches were conducted in order to anticipate the behavior of oily pollutants in seawater distillation process.
There were essentially no mineral oils in seawater, but coastal seawater was occasionally polluted by oily substances which were disposed or effiuented from factories, tankers, oil wells, etc. when they moved to the fresh water from the polluted feed in desalination process, they gave unpleasant smell and taste.
The simple distillation of some mineral oils mixed iri water or seawater were carried out under an atmospheric pressure. Those oils were almost immiscible, forming heterogeneous systems with water. They transfer into distilled water by steam-distillation. The volume of each oily component in the distillate agreed well with the calculated value. Even if there was a very small amount of heavy oily materials in the feed seawater, they polluted fresh water and gave foul smells.
Those oily pollutants in fresh water should be treated and removed by means of activated carbon adsorption process and so forth.View full abstractDownload PDF (3223K) -
Kohji SAKANE, Shunsaku KATOH1985 Volume 39 Issue 1 Pages 37-41
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSInductively coupled plasma-optical emission spectrometry (ICP-OES) was applied to the determination of uranium in the eluate that was obtained in the extraction process of uranium from sea water.
Optimization of operating parameters of ICP-OES and spectral line profiles were examined. A linear calibration curve up to 30μEg/ml and a detection limit of 0.02μEg/ml for standard solutions were obtained by using the uranium 409.01nm line.
Uranium in the acidic eluates from amidoxime resin was determined by ICP-OES. Analytical results agreed with those obtained by spectrophotometry with Arsenazo III and fluorometry. As a result, ICP-OES was found to be useful for the rapid determination of uranium in the eluate.View full abstractDownload PDF (3084K) -
Studies on Environmental Analysis (Part 17)Yutaka SAITOH, Yoshimichi MAEDA, Akio YONEDA, Takatugu AZUMI1985 Volume 39 Issue 1 Pages 42-47
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSFor the X-ray fluorescent determination of vanadium in water, the preconcentration with sodium diethyldithiocarbamate (DDTC) and coprecipitant was investigated.Trace vanadium-DDTC complexdid not precipitate completely, while it coprecipitated quantitatively with chromium (VI), iron (III), iron (II) or cobalt (II) which formed stable DDTC-complexes in the pH range from 3 to 5. 0.5mg of coprecipitant and 20ml of 10w/v% sodium acetate buffer were added to 500 ml of a sample solution.The solution was adjusted to pH4.0, and then added to 3ml of 2w/v% DDTC solution. The coprecipitant including vanadium was then collected to undergo an X-ray fluorescent analysis. A microgram per liter level of vanadium in sea water was determined by calibration curve method.View full abstractDownload PDF (3559K) -
Chuichi MIZOGUCHI1985 Volume 39 Issue 1 Pages 48-54
Published: 1985
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDownload PDF (3600K)
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