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Volume 50 (1996)
- Issue 6 Pages 389-
- Issue 5 Pages 299-
- Issue 4 Pages 211-
- Issue 3 Pages 149-
- Issue 2 Pages 51-
- Issue 1 Pages 3-
Volume 50, Issue 6
Displaying 1-9 of 9 articles from this issue
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Haruhiko OHYA, Takashi SUZUKI, Shin-ichi NAKAO, Shigeru KATO, Jiro SUG ...1996 Volume 50 Issue 6 Pages 389-395
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSSerious troubles regarding scale formation may occur when the amount of recovered water from sea water increases. The main constituents of the scale are CaCO3, Mg(OH)2, CaSO4 and so on, all of which are salts of alkaline earth metals. Therefore, if a key technology is developed with which the main constituents of the scale, alkaline earth metal ions such as CaCO3, Mg(OH)2, CaSO4 and so on, can be removed and/or separated from sea water the recovery of desalted water from raw sea water using high-pressure reverse osmosis (HPRO) can be increased up to 75-80%, the solubility limit of the remaining scale components. Then it will be possible to make use of all valuable materials that exist in sea water, using an integrated system that combines conventional recovery technologies with a set of the proposed technologies such as HPRO, an alkaline earth metal ions removal process, inorganic ion exchangers for recovering trace elements and so on. Furthermore, almost complete utilization of sea water may be accomplished by using of the brackish water by product for salt-resistant plants such as mangrove, salt bush and, if possible, gene-recombinated plants.View full abstractDownload PDF (6056K) -
Shigeru KATO1996 Volume 50 Issue 6 Pages 396-405
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThe objective this research is to assess the potential for culture of agricultural crops in utilized land, salt affected land and gulf land areas. The retional behind this approach is the fact that Middle East countries do not have a good supply vegetables and other crops due to salt affected, dry and desert lands as well as salt affected inland areas.
The tested vegetables and crops under saline conditions were about 150 species as first step selection. Tested 7 vegatables species were selected from first step study. Stand and culture solution used was designated condition for No.1 and No.2 Ohtsuka liquid fertilizer (ohtsuka chemical inc.). The other conditions were prepared S-300, S-1000, S-3000 amd S-10,000.(S-300 contains 0.03% NaCl.) Harvested vegetables were measured and compared in fresh weight tested all vegetables. Difference of fresh weight was rcognized. 4 vegetables were very good growth under S-0 condition. Sparkler and Takafuji (a kind of turnip) increased fresh weight at S-1000. Fresh weight of Sparkler and Takafuji of S-3000 were recognized similar fresh weight of S-0 condition. This two turnips suppsed that can grow under about 10 times dilution of sea water. Amount of Na and Cl ions in plants rised up with increased NaCl concentration in culture solution. On the other hand, amount of K, Mg and Ca ions in plants decreased. The highest amount of organic acid in plant was malic acid. Secondly, amount of organic acid was citric acid. Produced oxalic acid in many halophytes was nearly not recognized in tested vegetable plants. Main components of sacchar ides were glucose and fractose in plants. Secondly, sucrose and maltose were also detected in tested plants.View full abstractDownload PDF (7070K) -
Shin-ichi NAKAO1996 Volume 50 Issue 6 Pages 406-412
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSTwo types of reverse osmosis (RO) process were proposed to obtain high recovery of fresh water in sea water desalination. The membrane parameters, the reflection coefficient o, the solute permeability P, the pure water permeability Lp, which are necessary in the process simulation were determined by experiments for three kinds of membranes commercially available, NTR-70SWC sea water desalination RO membrane, NTR729HF high flux and low rejection nanofittration (NF) membrane, NTR759HR high rejection NF membrane. Maximum pressure applied for the RO membrane in the experiments was20 MPa, and 10 MPa for the NF membranes. The NaCl concentration in feed ranged from 0.15 to 12 wt%. The process simulated were single-stage one-pass process with NTR-70SWC or NTR759HR and multistage (two or three stages) recycle process with NTR729HF and NTR759HR, and energy consumption and membrane area required were calculated. On the multi stage processes with NF membranes, both the energy and membrane area were almost the same, but the single-stage processes with NF or RO membrane required less energy and more membrane area, especially the membrane area for the process with 70SWC was much more than that for other processes because of the small Lp value.View full abstractDownload PDF (4183K) -
Development of Selective Inorganic Adsorbents for Recovery of Multivalent AnionsMasamichi TSUJI1996 Volume 50 Issue 6 Pages 413-425
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSIon-exchange adsorption could be expressed in terms of the corrected selectivity coefficient for prediction of ion-exchange property at concentration and temperature conditions different from those used for their determhlations. The plot of corrected selectivity coefficient vs. the concentration of exchanging ions in exchanger is conjugative with the expression of thermodynamic constant. It also generates the ion-exchange isotherm and distribution coefficients.
Amorphous titanic acid has ben established for selective recovery of multivalent oxoanions in concentrated sea water. The ion-exchange selectivity was studied for halide ions and various oxoanions such as BrO3-, IO3-, Te (IV), Se (IV), V (V), P (V), Sb (V), As (V), W (IV). The latter oxoanions have been found to be very selectively adsorbed from sea water and could be removed efficiently. Chromatographic separations of BrO3- from IO3- and I- from Te (IV) were successfully performed using a small titanic acid column with 5mm internal diameter and 4cm length at room temperature. These oxoanions could be eluted using 0.1-1 M NaOH solution.View full abstractDownload PDF (8017K) -
Takashi SUZUKI, Hideto SAKANE, Toshio SATO1996 Volume 50 Issue 6 Pages 426-433
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSFluorine micas contain K+ at the interlayer in its original form. Therefore, Na+-substituted fiuorine micas may be very selective for alkaline metal ions in ion-exchange reactions, i. e. the ion-memorizing effect. In this study, the ion-exchange properties of Na-form taeniolite, NaMg2LiSi4O10F2·nH2O,(NaT) for K+ and other ions are discussed.
NaT demonstrated the ion-memorizing effect for K+. Ca2+ and Mg2+ were also selectively removed from aqueous sohltions. However, the selectivity for K+ was hardly affected by the presence of alkaline earth metals in mixed aqueous solutions. NaT selectively took up NH4+ just K+ did. It is expected that the changes in the interlayer distance of NaT during the exchange reaction slead to a difference of its exchange properties between K+ and Ca2+ or Mg2+.
In conclusion, NaT can be used as the selective adsorbent for K+ and NH4+ from seawater and living wastewater.View full abstractDownload PDF (6148K) -
Masahiko AIHARA, Haruhiko OHYA, Youichi NEGISHI, Kazuo YANASE1996 Volume 50 Issue 6 Pages 434-442
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSIt is hoped that the cation exchange resins in “Development of a Resource and Energy-Saving Integrated System for the Complete Usage of Sea Water” will selectively adsorb both calcium and magnesium ions from the feed sea water, and desorb the both ions by exchanging ions with sodium ion concentrated waste water from this system after extracting the fresh water and the valuables. The cation exchange resins were prepared by means of suspension polymerization from styrene, methyl acrylate and ethyl acrylate as a monomer, and di-vhlyl-benzene as a crosshnking agent. These diameters were 0.3 [mm]-0.6 [mm]. We studied the characteristics of the resins, such as the following properties of adsorption and desorption for calcium and magnesium ions.
1) The sulfonated polystyrene resin with eight percent di-vinyl-benzene crosslinking possessed an ion exchange capacity of 1.1 [meq/ml-Resin].
2) The resins polymerized in this study adsorbed calcium ion selectivity in sodium and calcium solutions.
3) The properties of adsorption and desorption of the ethyl acrylate-di-vinyl-benzene (EA-DVB) and the styrene-di-vinyl-benzene (St-DVB) resins regenerated after 30 cycles.
4) Using the column method, the EA-DVBresin demonstrated the greatest adsorption amount, and the St-DVB resin demonstrated the fastest desorption velocity.View full abstractDownload PDF (6065K) -
Mingzhong LI, Keiichiro SAITO, Mitsuru HIGA, Akihiko TANIOKA1996 Volume 50 Issue 6 Pages 443-448
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSA weakly amphoteric polymer was prepared using silk fibroin. The salt permeability coefficient of the membrane was measured at various pH levels in the outer solution. The possibility of piezodialysis was discussed using phenomenological equations based on the non-equilibrium thermodyllamics. The hydraulic permeability coefficient lp was not affected by the pH. On the other hand, the reflection coefficient σ and the solute permeability coefhcient ω were affected by pH. At the isoelectric point, σ was at its minimum value and ω was at its maximum value. It is possible to change the solute permeability by controlling the pH in the outer solution and the state of the fixed charge groups.View full abstractDownload PDF (3510K) -
Toshikatsu SATA, Yasuhiko KAKUYAMA, Koji MATSUSAKI, Yasuhiro KAGIYAMA, ...1996 Volume 50 Issue 6 Pages 449-460
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSAnion exchange membranes having various pyridinium groups were prepared by the reaction of copolymer membranes having a vinylpyridine moiety (4-vinylpyridine-divinylbenzene, 4-vinylpyridine-2-vinylpyridine-divinylbenzene and 2-vinylpyridine-divinylbenzene) with various alkyl halides (methyl iodide, ethyl bromide, npropyl bromide, n-hexyl bromide and 1, 3-dibromopropane). Though the copolymer membrane prepared from 4-vinylpyridine and divinylbenzene was easily quaternized with alkyl halides, the copolymer membranes with the 2-vinylpyridine moiety was difficult to quaternize due to steric hindrance.
As a result of electrodialysis of mixed salt solutions, in general, permeation of hydrophobic anions, nitrate ions and bromide ions compared to chloride ions increased with increasing hydrophobicity of the anion exchange groups or the membranes, especially nitrate ions. On the other hand,the permeation of sulfate ions through the membranes was almost equal to that of chloride ions because of the high ion exchange capacity of the membranes, and the permeation of sulfate ions was hardly affected by the species of pyridinium groups in these membranes. Permeation of fluoride ions, which are strongly hydrated, decreased with increasing hydrophobicity of the membranes. Finally, the effect of crosslinking of the membrane with 1, 3-dibromopropane on the transport numbers of various anions relative to chloride ions was examined. The permeation of ions larger than chloride ions increased in the membrane prepared with 1, 3-dibromopropane compared to the membrane with n-propyl bromide. This might be due to the difference in the amount of n-propyl groups in the two membranes.View full abstractDownload PDF (9560K) -
Tokiaki ISHIKAWA1996 Volume 50 Issue 6 Pages 461-476
Published: 1996
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDownload PDF (9495K)
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