• Membrane Journal
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• v.12 no.1
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• pp.51-53
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• 2002

The hydrogen ions in poly (vinyl alcohol) (PVA)/sulfosuccinic acid (SSA) membranes substiuted with $Li^+, Na^+, and K^+/ $of monvoalent metal ions, $Mg^{2+}, Ca^{2+} and Ba^{2+}$ of divalent metal ions, and $Al^{3+}$ of trivalent metal ion. In addition, $Li^+ ions were exchanged with varing reaction time. The effects of metal ions exchanged were investigated in terms of methanol permeability -uling diffusion cell. The methanol permeabilies decreased in the sequence of $Na^+, Li^+ and K^+$ and this might be due to the 'Salting-out' effect while the methanol permeabilities for divalent and trivalent ion-substituted membranes were affected by the combined effects of salting-out, eletrostatic crosslinking and extent of metal ion substiution. As for $Li^+$ ions, methanol permeabilities of PVA/SSA membranes decreased in proportion to the degrees of subsituted $Li^+$ ions.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.790-793
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• 1996

The azacrown compound, 1,7-dioxa-4,10,13-triazacyclopentadecane-N,N',N"-tri(methyl-acetic acid)(N3O2-tri(methylacetic acid)) was synthesized by modified procedure of Krespan. Potentiometric method has been used to determine the protonation constants of N3O2-tri(methylacetic acid) and stability constants of complexes on the divalent transition metal ions (Co2+, Ni2+, Cu2+, and Zn2+) and trivalent metal ions (Ce3+, Eu3+, Gd3+, and Yb3+) with N3O2-tri(methylacetic acid). The stability constants for the complexes of the divalent transition metal ions studied in the present work with N3O2-tri(methylacetic acid) were 11.4 for Co2+, 11.63 for Ni2+, 13.51 for Cu2+, and 11.65 for Zn2+, respectively. Thus, the order of the stability constants for complexes on the transition metal ions with N3O2-tri(methylacetic acid) was shown Co2+ < Ni2+ < Cu2+ > Zn2+ as same as the order of Irving-Williams series. The stability constants of Ce3+, Eu3+, Gd3+, and Yb3+ trivalent lanthanide metal ion complexes of N3O2-tri(methylacetic acid) were, respectively, 11.26 for Ce3+, 11.56 for Eu3+, 11.49 for Gd3+, and 11.80 for Yb3+. The values of the stability constants on trivalent metal ions with the ligand are increasing according to increase atomic number, due to increase acidity. But the value of stability constant of Gd3+ ion is less than the value of Eu3+ ion. This disordered behavior is also reported by Moeller.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1337-1345
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• 2011

The removal performances of divalent heavy metal ions ($Pb^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Sr^{2+}$ and $Mn^{2+}$) were studied using the Na-P1 zeolite synthesized from Jeju scoria in the batch and continuous fixed column reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite decreased in the order of $Pb^{2+}$ > $Cu2^{2+}$ > $Cd^{2+}$ > $Sr^{2+}$ > $Mn^{2+}$ based on the selectivity of each ion to ionic exchange site of Na-P1 zeolite for single and mixed solutions in batch or continuous fixed column reactor. For mixed solution, each heavy metal ion uptake was lower than that in single solution, and especially the uptake for $Mn^{2+}$ decreased greatly. In batch reactor, the uptakes of heavy metal ions by synthetic Na-P1 zeolite were described by Freundlich or Langmuir equation, but they followed the former better than the latter. In continuous fixed column reactor, the maximum ion exchange capacity obtained for each of heavy metal ions, was about 90----- of that in batch reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite increased with the increase of initial heavy metal concentration and solution pH, and the decrease of the amount and particle size of synthetic zeolite.

• Membrane and Water Treatment
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• v.11 no.3
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• pp.201-206
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• 2020

Electrodialysis (ED) is used in wastewater treatment, during the processing and recovery of beneficial materials, to produce usable water. In this study, sulfate and chlorine ions, which are the anions majorly used for electroplating, were studied as factors affecting the recovery of copper, nickel and water from wastewater by electrodialysis. Although the removal rates of copper and nickel ions were slightly higher with the use of chlorine ions than of sulfate ions, the removal efficiencies were above 99.9% under all experimental conditions. The metal ions of the plating wastewater flowed through the ion exchange membrane of the diluate tank and the concentrate tank while all the water moved together due to electro-osmosis. The migration of water from the diluate tank to the concentrate tank was higher in the presence of a monovalent chloride ion compared to that of a divalent sulfate ion. When sulfate was the anion used, the recoveries of copper and nickel increased by about 25% and 30%, respectively, as compared to the chloride ion. Therefore, when divalent ions such as sulfate are present in the electrodialysis, it is possible to reduce the movement amount of water and highly concentrate the copper and nickel in the plating wastewater.

• Journal of Environmental Science International
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• v.8 no.3
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• pp.399-409
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• 1999

The three domestic natural zeolites(Yong dong-ri (Y), Daesin-ri (D), Seogdong-ri (S)) harvested in Kyeongju-shi and Pohang-shi, Kyungsangbug-Do, were pretreatd with each of the NaOH, $Ca(OH)_2$ and NaOH following HCl solutions, and the removal performances of divalent haevy metals(Cu, Mn, Pb, and Sr) for natural and pretreated zeolites were investigated and compared in the single and mixed solutions. The natural zeolite-heavy metal system attained the final equilibrium plateau within 20 min, irrespective of initial heavy metal concentration. The heavy metal uptakes increased with increasing initial heavy metal concentration and pH. The heavy metal uptakes for natural zeolites decreased in the following sequences : D>Y>S among the natural zeolites; Pb>Cu>Sr>Mn among the heavy metals. The pretreated zeolites showed higher heavy metal removal performances than natural zeolites and decreased in the order of NaOH, NaOH following HCl, $Ca(OH)_2$ treatment among the pretreatment methods. The heavy metal ion exchange capacity by natural and pretreated zeolites was described either by Freundlich equation or Langmuir equation, but it followed the former better than the latter. The heavy metal uptakes for natural zeolites decreased in the mixed solution, in comparing with those in the single solution and especially, the manganese uptake decreased greatly in the mixed solution. The pretreated zeolites showed the improved removal performances of heavy metals in the mixed solution than in the single solution and the heavy metal uptakes by those in the mixed solution showed the same trends in the single solution among the chemical treatment methods and heavy metals.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.912-918
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• 2011

Tetraaza Schiff base macrocyclic ligands, $L^1$,$L^2$ and their transition metal chelates have been synthesized and characterized by elemental analyses, IR, electronic, EPR and $^1H$ NMR spectra, TGA and magnetic measurements. The molar conductance of one milli-molar solution of the complexes measured in DMF indicates that the divalent metal complexes are nonelectrolyte while those of trivalent metal ion, are 1:1 electrolytic in the same solvent. The reduction of Racah parameter from the free ion value confirms the presence of considerable covalence of metal ligand sigma bond in the Co(II) and Mn(II) complexes. The EPR spectra of Cu(II) complexes at room temperature shows axial symmetry indicating a $d_x{^2}_{-y}{^2}$ ground state with significant covalent character. The thermal analysis suggests that the complexes do not contain water molecules because only the metal is left as residue.

• Animal cells and systems
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• v.14 no.4
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• pp.245-252
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• 2010

Iron uptake in mitochondria and fractionated mitochondria compartments was studied to understand iron transport in heart mitochondria. The inner membrane is most active in iron uptake. Mitochondrial uptake was dependent on iron concentration and the amount of mitochondria. Iron transport was inversely proportional to pH in the range of 6.0 to 8.0. Iron transport reached a maximum after 30 min of incubation at $37^{\circ}C$. Iron uptake was inhibited by 1 mM ATP and stimulated by 1 mM ADP. The oxidative phosphorylation inhibitor oligomycin inhibited iron uptake, but rotenone and antimycin A did not. The divalent ions $Mg^{2+}$, $Cu^{2+}$, $Mn^{2+}$, and $Zn^{2+}$ suppressed iron uptake at $10\;{\mu}M$ and stimulated it at 1 mM. The divalent ion $Ca^{2+}$ stimulated iron uptake at $10\;{\mu}M$ and suppressed it at 1 mM, competing with iron. The uptake of calcium was stimulated by 10 to $1000\;{\mu}M$ ATP, while iron uptake was stimulated reciprocally by 10 to $1000\;{\mu}M$ ADP, suggesting that these ions have movements similar to those of ATP and ADP.

• Journal of the Korean Chemical Society
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• v.67 no.4
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• pp.222-225
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• 2023

Metallic salts of C10-18 aliphatic carboxylic acids were prepared and their scanning electron microscopic images were analyzed for the morphology dependency with the metal and the carboxylic acid. Regardless of metal ion, metal salts of dicarboxylic acids showed a high crystallinity with a fiber image (SuA-Na). The aromatic dicarboxylates also represented a morphology of a rectangular-rod or board shapes (IA-Li, IA-Ba). With Na ion, most aliphatic carboxylate (MA, PA, SA) showed a fiber-like crystallinity. However, other monovalent Li, K and multivalent Mg, especially Al ion resulted a glassy-amorphous in the metallic salts of acids (MA, PA, SA). With divalent Ba and Ca ions, the metal salt of aliphatic acids expressed a branched round cluster shape as in SA-Ca, SA-Ba. Both Li and Mg ions with a similar size showed a strong morphological similarity in the metallic salts of aliphatic acids MA, PA, SA. In the case of Na and Ca ions with a similar size (98, 106 pm), both ionic salts of stearic acid gave a branching effect for a fiber or round granular image. In the case of hydroxyl-aliphatic acids (HLA, HPA, HSA), the fiber images in HLA-Na and HSA-Na was appeared about 100 nm thicker than those of nonhydroxycarboxylates (LA-Na, SA-Na). The metallic salts of unsaturated C-18 carboxylic acids (OlA, LeA and LnA) showed an amorphous glassy image due to a kinked carbon chain.

• Membrane Journal
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• v.11 no.3
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• pp.133-139
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• 2001

The hydorgen ions in PVA/SSA membranes were substituted with monovalent metal ions, $Li^{+}$, $Na^{+}$, $K^{+}$, divalent metal ion forms, $Mg^{2+}$, $Ca^{2+}$, $Ba^{2+}$, trivalent metal ion forms, $Al^{+}$. The effect of exchange with metal ions was investigated through the swelling measurement and pervaporative experiments for water-ethanol and water-methanol mixtures at various operating conditions. In addition, ESCA analysis was carried out to study the substitution of the metal ions in membranes. The swelling ratio decerased in the sequence of $Li^{+}$, $Na^{+}$, $K^{+}$ and this might be due to the 'salting-out` effect while the swelling ratios for divalnet and trivalent ion-substituted membranes were affected by the combined effect of salting-out, electrostatic crosslinking and extent of metal ion substitution. For the pervaporation performance, PVA/SSA-$H^{+}$membrane showed the lowest flux and highest separation factor for all aqueous ethanol solutions. The typical results of the flux, 59 g/$m^{2}$hr and the separation factor, 44 were obtained at $50^{\circ}C$ for 90% ethanol aqueous mixture. For water-methanol solutions, the PVA/SSA membranes substituted with monovalent PVA/SSA membranes substituted with divalent and tribalent metal ions, both `salting-out` and electrostatic effects affected the pervaporative results.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.149.3-150
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• 2003

CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)