• Journal of Environmental Science International
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• v.5 no.6
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• pp.779-783
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• 1996

Cation exchange distribution coefficients of poly(dithiocarbamate) were presented for $Cd^{2+}$, $Cr^{3+}$, and $Pb^{2+}$ in HCI. The distribution coefficients were determined tv using the batch method. Based on these distribution data, the separation possibilities of the heavy metal ions were discussed. The distribution coefficients of three heavy metal ions on dithiocarbamate resin were decreased as HCI concentrations were increased. The selective separation of $Cr^{3+}$ and $Cd^{2+}$ was possible by using 0.1M HCl in dithiocarbamate resin and the reproducibility test showed that the average absorptivity of resin was 90% in the case of $Cd^{2+}$ ion by the column method.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.445-449
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• 1999

Hydrophilic polyphosphazenes were synthesized from hydrophobic polyphosphazenes by adding methoxyethylenoxy side chains and cast by dip-coating method into membranes supported on porous polypropylene mesh filter sheet for metal separation testing. A solution of $Cr^{3+},\;Co^{2+},\;Mn^{2+}$ nitrates was used in diffusion experiments which were conducted from $25^{\circ}C$ to $60^{\circ}C$. lt was found that the ion transport properties were increased as the repeating number of ethylenoxy side chain increased. Membrane from trifluoroethoxy methoxyethoxyethoxyethoxy co-substituted polyphosphazenes was found to separate $Cr^{3+}$ ion from $Mn^{2-}$ and $Co^{2+}$ ions with separation factor of 4.5 at $60^{\circ}C$.

• Journal of Integrative Natural Science
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• v.10 no.1
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• pp.43-50
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• 2017

Synthetic resins were combined 1-aza-12-crown-4 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 8%, and 16% crosslink by a substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, SEM, surface area, and IR-spectrum. As the results of the effects of pH, crosslink of synthetic resin, and dielectric constant of a solvent on metal ion adsorption for resin adsorbent, the metal ions showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in ethanol solvent was the order of uranium ($UO_2{^{2+}}$) > cobalt ($Co^{2+}$) > dysprosium ($Dy^{3+}$) ion, adsorbability of the metal ion was the crosslink in order of 1%, 2%, 8%, and 16% and it was increased with the lower dielectric constant. In addition, theses metal ions could be separated in the column with 1% crosslink resin by using nitric acid (pH 2.0) as an eluent.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.493-499
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• 2004

Rejection characteristics of heavy metals by nanofiltration membranes were investigated. Nanofiltration membranes rejected heavy metals much better than chloride, sulfate and TOC, of which concentration in synthetic wastewater was higher than that of heavy metals. To consider rejection characteristics of various metals by nanofiltration membranes, separation coefficient, which is the ratio of the metal permeation rate to the chloride ion or TOC permeation rate, was introduced. In spite of different materials and different nominal salt rejection of nanofiltration membrane used, the separation coefficients of metals were nearly the same. In particular, the separation coefficient of arsenic against chloride ion and TOC was larger than any other separation coefficient of heavy metals. These phenomena were observed in the relationship between the molar conductivity and the separation coefficient for heavy metals.

• Analytical Science and Technology
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• v.6 no.3
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• pp.261-265
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• 1993

The ion exchange capacity of DBPDA ion exchanger, {(4,5):(13,14)-dibenzo-6, 9, 12-trioxa-3, 15, 21-triazabicyclo [15.3.1] heneicosa-1(21), 17, 19-triene-2, 16-dione : DBPDA ion exchanger} was 4.2meq/g. The distribution coefficients of alkali and alkaline earth metal ions in the various concentrations of hydrochloric acid were determined using DBPDA ion exchanger. Also alkali and alkaline earth metal ions were separated using DBPDA ion exchanger. From these results the effect of pH of solution and ionic radii of the metal ions on the distribution coefficients of alkali and alkaline earth metal ions were discussed.

• Fibers and Polymers
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• v.3 no.1
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• pp.14-17
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• 2002

Development of a novel fixed site carrier membrane (FCM), supported by PET fabric for metal ion separation is reported. The membranes were prepared by dipping PET fabric into the methylene chloride solution of Poly(5-vinyl-m-phe-nylene-m'-phenylene-32-crown-10) (P(VCE)), a polymeric metal ion carrier. It was found that the flux of mono-valent metal ion transported across the membrane is signif=cantly differed from each other and the flux decreases in the order $Cs^+$>$Rb^+$>$K^+$>$Na^+$>$Li^+$ irrespective to the anion except perchlorate anion. It was explained in terms of the stability of the complex, formed by crown ether unit of the P(VCE) and the various metal ions, meanwhile, the lower rate of transport in the presence of perchlorate anion was ascribed to its low hydrophilicity.

• Clean Technology
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• v.12 no.1
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• pp.37-44
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• 2006

The effectiveness of inorganic oxides (DT-30), anionic exchange resin (DT-60) and carbon absorbent (DT-80, DT-90) on the equilibrium and continuous separation characteristics and removal of cobalt, cesium and iodide ion in the waste water was investigated. As a result, DT-30, DT-80 or DT-90, and DT-60 showed excellent separation properties on the cesium, cobalt and iodide respectively. In the equilibrium experiment, the adsorption amount of cesium for DT-30 increased with temperature, but increasd largely with pH. In case of DT-80, adsorption of cobalt was depended on pH but was not influenced by temperature. In the continuous system by passing a heavy metal ion solution through the ion exchange tower, DT-30, DT-90 and DT-60 showed good separation characteristic for cesium, cobalt and iodide respectively. In this case, separation characterization of DT-30 on the cesium and of DT-60 on the iodide were better than that of DT-90 on the cobalt. From the experiment on the effect of impurities on the ion exchange characteristics, impurities such as surfactant and oil did not influence the efficiency of DT-90. In the mean while, ion separation capacity of DT-30 were decreased largely by impurities such as surfactant and oil. Also, surfactant had a strong influence on the effectiveness of DT-60. Accordingly, it turned out to be very important thing that impurities should be removed in the preprocessing stage.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.96-101
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• 2005

A theory for the material transports through ion exchange membrane has been developed on the basis of nonequilibrium thermodynamics by removing the assumption of solvent flow in the previous paper and applied to a detailed study of the ionic transport properties of new charged mosaic membrane(CMM) system. The CMM having two different fixed charges in the polymer membrane indicated unique selective transport behavior then ion-exchange membrane. The separation behavior of ion transport across the CMM with a parallel array of positive and negative functional charges were investigated. It was well-known the analysis of the volume flux and solute flux based on nonequilibrium thermodynamics. Our suggests preferential salt transport across the charged mosaic membranes. Transport properties of heavy metal ions, $Mg^{2+}$, $Mn^{2+}$and sucrose system across the charged mosaic membrane were estimated. As a result, we were known metal salts transport depended largely on the CMM. The reflection coefficient indicated the negative value that suggested preferential material transport and was independent of charged mosaic membrane thickness.

• Advances in materials Research
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• v.2 no.1
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• pp.15-36
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• 2013

Incorporation of polar functional moieties into polyethylene (PE) film has been achieved by graft copolymerization of polar monomers such as methacrylic acid (MAAc) and acrylamide (AAm) on to PE film, preirradiated with ${\gamma}$-rays from $^{60}Co$ source, using benzoyl peroxide (BPO) as initiator in aqueous medium. Percentage of grafting of MAAc and AAm was determined as a function of irradiation dose, monomer and initiator concentration, temperature, reaction time and amount of water. Maximum percentage of grafting of MAAc (1453%) and AAm (21.28%) was obtained at [MAAc] = $235.3{\times}10^{-2}$ mol/L, [AAm] = $23.4{\times}10^{-2}$ mol/L, [BPO] = $5.5{\times}10^{-2}$ mol/L and $16.5{\times}10^{-2}$ mol/L at $80^{\circ}C$, $90^{\circ}C$ in 180 min and 90 min respectively. The grafted PE films were characterized by FTIR, Thermogravimetric analysis (TGA) Scanning Electron Micrography (SEM) and X-ray diffraction methods. Some selective properties of grafted films such as swelling behavior, ion and metal uptake have been carried out. The biodegradation studies of the grafted PE films have also been investigated. The grafted films developed superior swelling behavior with maximum swelling (480%) in water as compared to pristine PE (13.55%), better thermal stability and ion and metal uptake studies showed promising results that can be effectively used for desalination of brackish water and separation of metals from the industrial effluents.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.159-164
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• 2000

For the purpose of development of a liquid membrane permeator which separates metal ions from aqueous solutions continuously and effectively, a continuous membrane permeator with the membrane solution trapped between extraction and stripping phases by two micro-porous hydrophilic films was manufactured. Experimental researches on the separation of zinc ion from aqueous solutions were performed in the liquid membrane permeator with 30 vol % D2EHPA solution in kerosine as liquid membrane. As results, the liquid membrane permeator separates zinc ion from aqueous solutions continuously and effectively in the wide range of operating conditions. A simple mass transfer rate model using equilibrium constant of the extraction reaction for the system used were proposed, and the model was compared with experimental results of separation of zinc ion in the permeator. And the effects of operating factors, such as space time, pH of extraction solution, extraction temperature, on the separation rate of zinc ion in the permeator were experimentally examined.