Active Transport of Heavy Metal Ions through Polymeric Blended Membranes
Project/Area Number |
62550694
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
化学工学
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Research Institution | Nagoya University |
Principal Investigator |
TAKEUCHI Hiroshi Nagoya University, 工学部, 助教授 (40043286)
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Project Period (FY) |
1987 – 1988
|
Project Status |
Completed (Fiscal Year 1988)
|
Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1988: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
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Keywords | Blended Polymeric Membrane / Ion Separation / Active Transport / Cation-Exchange Membrane / Permeation Mechanism / Plasma Polymerization / Pervaporation / エタノール / 金属イオン / 選択分離度 / イオン交換膜 / 膜透過機構 / イオン透過 / 重金属イオン / 濃縮・分離 / 有効拡散係数 |
Research Abstract |
[1] Two kinds of polymeric membranes were prepared by blending poly(isobutylene-alt.comaleic anhydride)(ISBN) and polystylene sulfonic acid(PSA) with polyvinylalchol(PVA). Studies were made on the ion-exchange equilibria, permeation and enrichiment separation of sodium, magnesium and nickel ions. Having a trend to swelling in weak acid solution as well as in water, the ISBN/PVA membranes allowed to acetallize; however, the permeation fluxes decreased remarkably as a result of lowering of the ion-exchange capacity. The flux data are inversely proportional to the membrane thickness; then, effective diffusivities of the metal ions in the membrane were evaluated from the permeation rate and ion exchange equilibrium. For the binary ionic solutions, separation factor of heavier metal to sodium ion was also determined from the maximum concentrations under conditions of uphill transport. It was found that the separation factor corresponds to the ratio of each initial flux. [2] Permeation rates
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of metal ions across a cation-exchange membrane, Neosepta CM-1, have been explained from two Models. model-1 includes the three parameters of the equilibrium constant,Kex, self-diffusion coefficients of metal ion and proton, while model-2 does the reaction rate constant at the membrane surface and a modified rate constant within the membrane as well as Kex. The former could be applied only for the permeation of monovalent ions. Thus, it appears that during the ion permeation the interface between the aqueous and membrane phases is not in equilibrium: non-equilibrium process. [3] To develop the membrane preferential to ethanol permeation, plasma polymerization of siloxanes was taken place on a porous polypropylene substrate membrane (Duragard 2500)in a reactor as well as the plasma surface-treatment of silicone casting membranes. The membrane perm-selectivity was examined in terms of the separation factor of ethanol to water and the permeation flux in pervaporation experiments under reduced pressure. The maximum separation factor is found to be about 10 for a casting membrane similar to silicone rubbers; however, the plasma polymerization of hexamethyldisiloxane brought about lower selectivity but higher flux of ethanol. Presently more preferential membranes are being developed to apply for pervaporation processes. Less
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Report
(3 results)
Research Products
(7 results)