• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.03a
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• pp.162-163
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• 2009

Colorimetric chemosensors are now considered as one of the most effective analytical method used in the environmental monitoring. In this study, 10 new direct dyes were synthesized to be used as colorimetric chemosensor. When metal ions such as $Al^{3+},\;Ca^{2+},\;Cd^{2+},\;Cr^{3+},\;Cu^{2+},\;Fe^{2+},\;Fe^{3+},\;Hg{^2+},\;Li^+,\;Mg^{2+},\;Na^+,\;Ni^{2+},\;Pb^{2+}\;and\;Zn^{2+}$ were added to the solutions of new dyes, the colors of the solutions were changed and can be easily detected by eyes without any expensive equipments. Some metal ions were coordinated to the new direct dyes forming complex. The experimental data and conclusions were rationalized by UV-VIS spectroscopy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.640-647
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• 1997

Wagnerite ($Mg_2PO_4F)$ was successfully synthesized in a sealed platinum tube and the complete substitutions of $Co^{++}, Ni^{++}, Cu^{++} \;and\;Zn^{++}$for Mg were made in the wagnerite structure. Wagnerite did not decompose until it reached its melting temperature. It was observed that wagnerite underwent only one inversion at $1255^{\circ}C$, prior to melting at $1340^{\circ}C$. The lattice parameters of wagnerites were linearly increased by the substitutions of $Co^{++}$ and $Zn^{++}$ and decreased by the substitutions of $Ni^{++}$ and $Cu^{++}$. The substitutions of wagnerite with $Co^{++}, Ni^{++}$ and $Cu^{++}$ resulted in purple, orange and green colors, respectively, The colors of pigments became more intense and suitable for coloring of glazes and plastics as the amount of metal ions increased.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.930-934
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• 2005

A chloroform membrane system containing a given mixture of benzylaza-12-crown-4 and oleic acid is introduced for the selective and efficient transport of $Pb^{2+}$ ion. The transport was capable of moving metal ions ‘up-hill’. In the presence of ${S_2O_3}^{2-}$ion as a suitable metal ion acceptor in the receiving phase, the amount of lead ion transport across the liquid membrane after 150 minutes is (95.0 ${\pm}$ 1.7)%. The selectivity and efficiency of lead transport from aqueous solution containing $Tl^+,\;Ag^+,\;Mg^{2+},\;Ca^{2+},\;Co^{2+},$ $Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Hg^{2+}$ and $Cd^{2+}$were investigated. In the presence of thiosulfate as a suitable masking agent in the source phase, the interfering effects of $Ag^+\;and\;Cu^{2+}$ were diminished drastically.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.577-582
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• 2004

The azacrown compounds, 1,4-dioxa-7,10,13-triazacyclopentadecane-N,N',N''-triacetic acid, $N-ac_3[15]aneN_3O_2(II_a)$ and 1,4-dioxa-7,10,13-triazacyclopentadecane-N,N',N''-tripropioc acid, $N-pr_3[15]aneN_3O_2(II_b)$ were synthesized by modified methods. Potentiometry was used to determine the protonation constant of the $N-ac_3[15]aneN_3O_2\;and\;N-pr_3[15]aneN_3O_2$. The stability constants of complexes of the trivalent metal ions of $Ce^{3+},\;Eu^{3+},Gd^{3+},and\;Yb^{3+}$ and divalent metal ions of $Co^{2+},\;Ni^{2+},\;Cu^{2+},\;and\;Zn^{2+}$ with the ligands $N-ac_3[15]aneN_3O_2\;and\;N-pr_3[15]aneN_3O_2$ have been determined at $25{\pm}0.1^{\circ}C$ in 0.1 M $NaClO_4$ solution by potentiometric methods. The metal ion affinities of the two triazamacrocyclic ligands with three pendant acetate or propionate groups are compared to those obtained for the similar ligands, 1,7-dioxa-4,10,13-triazacyclopentadecane-N,N',N''-triacetic acid, and 1,7-dioxa-4,10,13- triazacyclopentadecane-N,N',N''-tripropioc acid. The trends in stability of complexes for different metal ions due to changes in the nitrogen position of the donor atoms of the ligand are discussed.

• Journal of Environmental Science International
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• v.10 no.2
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• pp.153-158
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• 2001

The biosorption abilities of different parts of waste brown seaweeds and their derivatives to remove heavy metals (Cd, Zn, Pb, Cu, Fe, Ni, Mn) from waste were evaluated. The two parts of waste brown seaweeds (Undaria pinnatifida) were stems and sporophyls, and the brown seaweed derivatives were alginic fibers, active carbon added alginate(AC-alginate) and dealginate. The abilities of the sporophyls to adsorb the heavy metal ions were higher than those of stems, and those of alginates were slightly higher than those of dealginate in single ion solution. With decreasing the size of biosorbents, the velocity and the amount of adsorption increased. The abilities of alginate to remove the heavy metal ions increased in multi-ion solutions by adding active carbon to alginate. The selectivity of these biosorbents(alginate, AC-alginate) to lead ion was highest and to manganese ion was lowest.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.88-88
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• 2001

The effects of pH and temperature on the degradation of prokidn in various buffered aqueous solutions(pH 1.32~9.66) and temperatures (35, 45 and 6$0^{\circ}C$ were investigated. The effect of ionic strength on the degradation of prokidin was also measured by varying ionic strength (0.0466~1.5) at pH 1.35 and 45$^{\circ}C$ The effect of metal ions on the degradation of prokidin at pH 7.35 and 3.98 was observed. The degradation of prokidin followed the pseudo- first- order kinetics. The degradation rate of prokidin showed pH-dependent and temperature-dependent patterns. Prokidin was very stable at the pH below 3.95, where half-lives at 35, 45 and 6$0^{\circ}C$were 294, 206 and 107 day, respectively. However, it degraded very rapidly at pH above 6.49; the half-lives at 35, 45 and 6$0^{\circ}C$were 60, 25 and 13 day, respectively. As ionic strength increased, the degradation rate of prokidin increased. Some metal ions increased the degradation rate in the rank order of Mn > Fe > Cu >Fe On the other hand. other metal ions such as Bi, Ba. Zn, Ni, Co did not show unfavorable effect.

• Journal of Environmental Science International
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• v.8 no.5
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• pp.607-610
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• 1999

The odor removal of landfill site leachate was carried out using pyroligenous liquid. The constituent elements of pyroligenous liquid and leachate were also analysed, employing Atomic Absorption Spectroscopy(AAS). Before order removal, the heavy metal ions such as Pb, Zn, Cu, Mn, Fe and Ni, in pyroligenous liquid were detected with ultra trace level. However, in this liquid, other metal ions such as As, Hg and Cd were not observed. The optimum condition for removing odor fromthe leachate was observed in 15 times dilution of pyroligenous liquid. Also, the degree of outlet odor was 1. Furthermore, the concentration of odor constituent compounds, e.g. $H_2S, NH_3, NH_2$ and $CO_2$ in the leachate was remarkably reduced. Finally, water quality of the leachate was improved.

• Journal of the Mineralogical Society of Korea
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• v.11 no.1
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• pp.20-31
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• 1998

Adsorption of metal elements onto illite and halloysite was investigated at $25^{\circ}C$ using pollutant water collected from the gold-bearing metal mine. Incipient solution of pH 3.19 was reacted with clay minerals as a function of time: 10 minute, 30 minute, 1 hour, 12 hour, 24 hour, 1 day, 2 day, 1 week, and 2 week. Twenty-seven cations and six anions from solutions were analyzed by AAs (atomic absorption spectrometer), ICP(induced-coupled plasma), and IC (ion chromatography). Speciation and saturation index of solutions were calculated by WATEQ4F and MINTEQA2 codes, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and relative abundances between initial solution and reacted solutions. The adsorption results showed that the adsorption extent of elements varies depending on mineral types and reaction time. As for illite, adsorption after 1 hour-reaction occurs in the order of As>Pb>Ge>Li>Co, Pb, Cr, Ba>Cs for trace elements and Fe>K>Na>Mn>Al>Ca>Si for major elements, respectively. As for halloysite, adsorption after 1 hour-reaction occurs in the order of Cu>Pb>Li>Ge>Cr>Zn>As>Ba>Ti>Cd>Co for trace elements and Fe>K>Mn>Ca>Al>Na>Si for major elements, respectively. After 2 week-reaction, the adsorption occurs in the order of Cu>As>Zn>Li>Ge>Co>Ti>Ba>Ni>Pb>Cr>Cd>Se for trace elements and Fe>K>Mn>Al, Mg>Ca>Na, Si for major elements, respectively. No significant adsorption as well as selectivity was found for anions. Although halloysite has a 1:1 layer structure, its capacity of adsorption is greater than that of illite with 2:1 structure, probably due to its peculiar mineralogical characteristics. According to FTIR (Fourier transform infrared spectroscopy) results, there was no shift in the OH-stretching bond for illite, but the ν1 bond at 3695 cm-1 for halloysite was found to be stronger. In the viewpoint of adsorption, illite is characterized by an inner-sphere complex, whereas halloysite by an outer-sphere complex, respectively. Initial ion activity and dissociation constant of metal elements are regarded as the main factors that control the adsorption behaviors in a natural system containing multicomponents at the acidic condition.

• Analytical Science and Technology
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• v.13 no.6
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• pp.810-814
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• 2000

The open-chain hexadentate $N_4$, $O_2$ ligands 1, 15-bis(2-hydroxybenzyl)-2, 6, 10, 14-tetraazapentadecane (BSATPD. 4HCl) has been synthesized as its tetrahydro-chloride salt and characterized by EA, IR, NMR, and Mass spectrum. Its protonation constants ($logK_n{^H}$) and stability constants ($logK_{ML}$) for $Cu^{2+}$, $Ni^{2+}$, $Co^{2+}$ and $Zn^{2+}$ ions were determined in aqueous solution by potentiometry and compared with those of analogous $N_4$, $O_2$ ligands contain ethtylenic spacers or propylenic spacers, which make six-membered chelate rings between the aliphatic nitrogen atoms.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.648-657
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• 1997

In order to investigate the polymorphism of wagnerite, the single phase of$Mg_3(PO_4)_2$ was synthesized by heating the stoichiometric mixture of $Mg_3(PO_4)_2$ and $MgF_2$ in a sealed platinum tube at $1040^{\circ}C$ (or 3 hours, One reversible inversion was detected at $1255^{\circ}C$ and the thermal decomposition was not observed until it reached the melting point. As a result, wagnerite is thermally stable enough to be used as pigments for glazes and plastics if substituted with divalent metal ions. The contractions of d-values in $Zn_4P_2O_8F_2$ and $Zn_3MgP_2O_8F_2$ phases were observed by the substitution with metal ions which resulted in intense purple, gold and green colors. Among the several attempts of charge - coupled sub-stitution, only $A^{1+}A_3^{2+}X^{5+}X^{6+}O_8_F2$ compositions were successful to synthesize the wagnerite phase.