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Volume 9 (1998)
- Issue 4 Pages 166-
- Issue 3 Pages 116-
- Issue 2 Pages 74-
- Issue 1 Pages 2-
Volume 9, Issue 4
Displaying 1-3 of 3 articles from this issue
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Yoko UCHIDA, Isao TOMITA, Kenji TOMURA1998 Volume 9 Issue 4 Pages 166-174
Published: December 31, 1998
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSMultitracer techniques have been applied to the study on adsorption behavior of such ion exchangers as amorphous and crystalline zirconium phosphates and their homologues as well as ion exchange resins by using the fission products of uranium. It was found that the distribution coefficients of many cationic radionuclides were relatively high for γ-zirconium phosphate and amorphous one. Zirconium and niobium behave uniquely, and selective sorption of barium on α-titanium phosphate was observed. Multitracer technique by use of fission products provides, at least qualitatively, useful means to elucidate simultaneously the sorption behavior of many kinds of ions under the same environment.View full abstractDownload PDF (936K) -
Ken-ichi OKAMOTO1998 Volume 9 Issue 4 Pages 175-182
Published: December 31, 1998
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSSynthesis, morphological structure, and gas separation and pervaporation properties of typical zeolite membranes are briefly introduced. Zeolite membranes are prepared hydrothermally on the surface of porous supports. They are composed of a thin dense layer of zeolite crystals. Molecules permeate through zeolitic pores and intercrystalline pores (non-zeolitic pores) in parallel. If one molecule in a mixture is too large to enter the pores, then separation can be obtained by molecular sieving. If both components in the mixture can permeate, then separation can be obtained due to differences in adsorption properties. Preferential adsorption of one component inhibits or blocks the other from entering the pores, and results in a high-efficiency separation. NaA zeolite membrane with Si/Al ratio of 1 preferentially permeates water from organic liquids, whereas ZSM-5 zeolite and silicalite membranes with high Si/Al ratios preferentially permeate organics and n-alkanes from aqueous solutions and hydrocarbon mixtures, respectively. NaY zeolite membrane preferentially permeates alcohols from nonpolar organic liquids.View full abstractDownload PDF (2419K) -
Yoshihide KAWAMURA1998 Volume 9 Issue 4 Pages 183-191
Published: December 31, 1998
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSHighly porous chitosan beads with any desired values of physical properties were systemati-cally formed by dropping chitosan/acetic acid solution into aqueous NaOH solution. There-after, a poly (ethylene imine) was introduced into the chitosan beads. The possibility of using the Polyaminated chitosan beads (PEI-CS) for recovery of mercury from municipal waste incineration plant was investigated. Commercial chelate resin particles cannot be used repeatedly since the adsorption of Hg (II) on the resin is very strong. On the other hand, recovery of Hg (II) adsorbed on PEI-CS with sulfuric acid solution was technically feasible. The equilibrium isotherm and the breakthrough curve for adsorption of Hg (II) on PEI-CS were compared with those for Unicellex UR-120H which was the best commercial chelate resin for removal of Hg (II) in Japan. The intraparticle effective diffusivity in PEI-CS was about two times larger than that in UR-120H, and adsorption capacity Hg (II) on PEI-CS was also larger than that on UR-120H.View full abstractDownload PDF (1994K)
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