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Volume 63 (2009)
- Issue 6 Pages 359-
- Issue 5 Pages 287-
- Issue 4 Pages 199-
- Issue 3 Pages 115-
- Issue 2 Pages 53-
- Issue 1 Pages 1-
Volume 63, Issue 2
Displaying 1-11 of 11 articles from this issue
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Greeting
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Akihiko Tanioka2009 Volume 63 Issue 2 Pages 53
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSDownload PDF (744K)
Special Issue : “Membranes & Ion-Exchange for Sustainable Future Desalination, Water Recycling and Ultra Purified Water”
Review
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Keiichiro Saito2009 Volume 63 Issue 2 Pages 54-57
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSIn this study, fundamental aspects of permeation phenomena through charged membrane were discussed. Permeation behavior of particles through membranes is principally influenced by the poresize of the membrane and the size of permeating particles. If there are fixed charges within the membrane phase, the electrostatic interaction between the particles and the fixed ionic groups should also be considered. The discussion mentioned above follows the gradient of electrochemical potential of permeating particles based on equilibrium thermodynamics or the phenomenological equation based on non-equilibrium thermodynamics. Measurement of membrane potential is an effective method for observing the movement of ions permeating through it or the interaction with the fixed charge within it, by which data permselectivity of ions could be explained.
Along with the properties cited above, some applications of charged membranes, including reverse osmosis (RO), pressure retarded osmosis (PRO), polymer electrolyte fuel cell (PEFC) and iontophoresis, were explained. By considering the ionic interactions between particles and fixed charges within the active layer of the RO-membrane, the production of purified water by the RO process should become more effective. We can change osmotic power into electricity based on PRO. Although the PRO process now uses existing membranes for the RO process, a newly developed membrane fitting the process is required. If charged membranes made of hydrocarbon are used for PEFC, the newly installed system to provide electricity would be more effective and more ecologically friendly. Iontophoresis is a relatively new application using charged membranes. It is a non-invasive method for transdermal drug delivery that can give us safer medical treatments. At last, charged membranes will be a key factor for the sustainable future of our society.View full abstractDownload PDF (1626K) -
Kazuyoshi Miyoshi, Kyoichi Saito2009 Volume 63 Issue 2 Pages 58-62
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSIon-exchange membranes for salt production were prepared by means of radiation-induced graft polymerization and chemical modifications. An epoxy-group-containing vinyl monomer, glycidyl methacrylate, was graft-polymerized onto a high-density polyethylene (HDPE) film. Subsequently, the produced epoxy group was converted into anion- and cation-exchange groups by means of the reactions with trimethyammonium chloride and sodium sulfite, respectively. Charged polymer chains invaded the amorphous domain of the HDPE film to provide the permeation path for ions driven by the electric field. The resultant ion-exchange membranes exhibited almost the same brine concentration and membrane resistance as commercially available ion-exchange membranes.View full abstractDownload PDF (2411K)
Commentary
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Hiroaki Harakawa, Jun-ichi Kanno, Makoto Komatsu2009 Volume 63 Issue 2 Pages 63-67
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSIon exchange non-woven fabrics (IEN) and ion conductive spacers (ICS) have been manufactured by means of radiation-induced graft polymerization (RIGP) in Ebara Corporation. These products are used for industrial water processing by semiconductor makers and others. The manufacturing process and characteristics of these products are described. The deionization performances for sodium chloride solution (10ppm) were compared by using a glass column of anion exchange nonwoven fabrics (A-IEN) and bead anion exchange resin (Dowex550A). A-IEN shows 2.5 times higher deionization efficiency than Dowex550A at the same bed depth. Effective surface area for deionization was estimated from the results of deionization efficiency. Effective surface area of A-IEN was calculated at 19m2/L, which is 3 times larger than Dowex550A. These results suggest that effective surface area per unit volume is more important than ion exchange capacity for deionization performance in the case of dilute aqueous solution. Thus, it has been proven that IEN has higher deionization performance than commercially available ion exchange resins.View full abstractDownload PDF (3912K) -
Totaro Goto2009 Volume 63 Issue 2 Pages 68-75
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSThe present situation for seawater desalination technology was introduced by comparing distillation processes (MSF and MED) with the reverse osmosis process. That led to the finding that the reverse process is essentially more favorable than distillation processes. It was followed by the recent trend for desalination process selection in the world and specific regions.
Next, the technology tendency was explained in terms of the following issues:
(1) Progress of membrane technology
(2) Improvement in efficiency of membrane module
(3) Trend of pretreatment
(4) Reduction of energy consumption
(5) Rationalization of systems
Based on the above analysis, a future strategy to be taken by Japan was discussed. The suggestion was that intensive research and development for pretreatment improvement should be carried out in order to maintain the present Japanese superiority in membrane technology.View full abstractDownload PDF (1213K) -
Yasuhisa Adachi2009 Volume 63 Issue 2 Pages 76-81
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSBehaviors of colloidal flocs are largely dependent on the formation of flocs. In other words, it is the floc that is usually the unit of motion in a natural water environment, water and waste water treatment plants and industrial process. So far, the geometrical model of fractal structure derived from the concept of cluster-cluster addition is the most accepted and useful method for describing floc structure. Rate of sedimentation and rheological properties can be described with the help of fractal dimension (D), which is the function of the number of contacts between clusters (Nc). It is pointed out that the determination of D in relation to various flocculation conditions is the most important subject to be analyzed. The permeable properties of floc structure remains to be worked out in the future.View full abstractDownload PDF (1737K)
Original Paper
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Shinya Yamasaki, Mayumi Nakasato, Akira Yamauchi2009 Volume 63 Issue 2 Pages 82-89
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSEach ion exchange element of a charged mosaic membrane was prepared as an independent ion exchange membrane by means of the cast method and the properties of the membrane were examined. In addition, to understand the details of the transport process in the membrane the electrochemical techniques using redox substances as a transport ion were employed to investigate the diffusivity of ion, the reversibility of the system, and the ion concentration in the membrane, and the results were compared to those of cast membranes. As a result, the cation exchange membrane showed approximately ideal membrane behavior. On the other hand, the anion exchange membrane suggested slightly non-ideal membrane performance because the hydrophobic interaction between the polymer micro gel in the membrane and transport ions used in this study was strong, and therefore a gap with ideal characteristics appeared. Furthermore, ion transport through a cation exchange membrane and an anion exchange membrane depended upon quantities of polymer gel content, which are ion exchange elements.View full abstractDownload PDF (1431K) -
Shoichiro Yoshida, Taiki Dohi, Humito Ando, Taiki Tateoka, Kaede Nukui ...2009 Volume 63 Issue 2 Pages 90-95
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSThe relationship between the arrangements of an ion exchange fabric packed in diluting compartment and the behavior of ion migration and water dissociation in an electrodeionization system (EDI) was investigated. The arrangement of an anion-exchange membrane (AM) / an anion-exchange fabric (AF) / a cation-exchange fabric (CF) / a cation-exchange membrane (CM) significantly enhanced the ion removal efficiency compared to the arrangement including a non-woven fabric made with both cation- and anion-exchange fibers (AM/AFCF/CM). The enhancement of ion removal efficiency was indicated also by current-voltage curves. The difference in the rate of ion removal between various salts was small in the arrangement AM/AF/CF/CM compared with that in the arrangement AM/AFCF/CM, which demonstrates an advantage for the production of ultrapure water by means of the EDI system.
The dissociation of water in the arrangement AM/AF/CF/CM was found to be promoted at the contact interface between the ion exchange fabrics with different polarity each other, whereas the water dissociation in other arrangements takes place at the interface of the ion exchange membrane and the ion exchange fabric. The formation of H+ and OH- ions due to the water dissociation in the interior of the diluting compartment should regenerate efficiently the ion exchanger packed in the diluting compartment, a fact facilitating the deionization in the arrangement AM/AF/CF/CM.View full abstractDownload PDF (2875K)
Original Paper
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Kazutoshi Iwamoto2009 Volume 63 Issue 2 Pages 96-99
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSImpedance measurements were performed on H-form cation-exchange resin particles under circulating high-purity water between a pair of platinum electrodes, across which an alternating current was applied for impedance measurements. The impedance was measured at voltages ranging between 10mV and 800mV and plotted on the complex plane to give two different groups, one of which might correspond to the charge-discharge process of electrical double layers and the other perhaps corresponding to the diffusion-control process.View full abstractDownload PDF (1302K) -
Izuru Kakuta, Toshiharu Sengoku2009 Volume 63 Issue 2 Pages 100-107
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSCu, Zn- and Mn- superoxide dismutase (SOD) and catalase (CAT) activities in the skin, hepatopancreas, and kidney from young Japanese flounder exposed to hyperoxia (HiO2), hydrogen peroxide (H2O2) and ultraviolet B (UV-B) light, which are oxidative stressors, were examined. These antioxidant enzyme activities in fish tissues were elevated significantly by exposure to the above oxidative stressors. In the HiO2-treated group, increased levels of hepatopancreas Mn-SOD at hours 24 and 72, and CAT at hour 24 were shown. Activities of kidney Cu, Zn-SOD at hour 24 and Mn-SOD at hour 12 also increased. Exposure to 6mg/L H2O2 elevated activities of skin Cu, Zn-SOD at hours 24 and 72, and CAT at hours 12 and 24. Cu, Zn-SOD level in hepatopancreas increased at hour 24. Activities of kidney Cu, Zn-SOD at hours 24 and 72, and Mn-SOD at hour 24 were also elevated. In fish exposed to 30mg/L H2O2, skin Cu, Zn-SOD and CAT levels increased after 12 hours. Increases in Hepatopancreas Cu, Zn-SOD at hours 24 and 72, and CAT at 12 and 72, in kidney Cu, Zn-SOD at hour 12, and Mn-SOD at 24 and 72 were recorded. In the UV-B radiation group, increased levels of skin Cu, Zn-SOD after 12 hours, Mn-SOD at hour 72, and CAT at hours 24 and 72 were observed. Mn-SOD activity in hepatopancreas also increased at hours 12 and 72. These results demonstrated that the antioxidant SOD-CAT system may play a useful role in reducing or preventing oxidative damage to skin, hepatopancreas and kidney of fish exposed to HiO2, H2O2 and UV-B light, though the fish were subject to remarkable oxidative stresses.View full abstractDownload PDF (2658K)
Letter from Laboratory
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Shin-ichi Nakao2009 Volume 63 Issue 2 Pages 108
Published: 2009
Released on J-STAGE: June 14, 2011
JOURNAL FREE ACCESSDownload PDF (1332K)
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