• Applied Biological Chemistry
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• v.28 no.2
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• pp.76-81
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• 1985

Miscible displacement techniques were used to investigate the influence of the organic matter treatment on the mobility of Cd, Zn, and Cu through soil columns. The heavy metals moved most readily through the Bonryang soil (Typic Udifluvents) of relatively low in CEC, pH, and organic matter content. Most parts of Cd and Zn eluted within 7 pore volumes, but Cu eluted between 5 and 15 pore volumes. Although the Gangseo soil (Aquatic Eutrochrepts) had lower in CEC and organic matter content than the Gyorae soil (Typic Distrandepts), the heavy metals moved faster through the Gyorae soil than through the Gangseo soil. Cu eluted more slowly and in smaller quantities than Cd and Zn from the Bonryang soil, but did not eluted from the Gangseo and the Gyorae soils at all during the experimental period. The motility of the heavy metals from the Bonryang and the Gangseo soils was in the order of Cd>Zn>Cu, but that of the Gyorae soil was in the order of Zn>Cd>Cu. Cd and Zn eluted after 5 and 20 pore volumes respectively, from the Bonryang soil treated with 3% compost but Cu did not elute even after 30 pore volumes were collected. By 7% compost treatment only small amountssof Cd eluted after 20 pore volumes. The liming of the Bonryang soil retarded the mobility of Cd, Zn, and Cu. Humic acid treatment did not reduce the motility of the Cd and Zn to the extent observed in the Bonryang soil with compost, but reduced a little motility of Cu.

• Resources Recycling
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• v.2 no.4
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• pp.33-41
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• 1993

In recovering copper from the copper converter slag, various separation methods, such as flotation, sieving and magnetic separation had been tried. The copper converter slag used in this study was prepared in two ways, i.e. 2 hour cooled and 10 hour cooled. From the flotation of copper slag, 45% Cu concentrate is obtained and the amount of copper recovery is about 93%. Before the flotation, copper in the slag could be also pre-recovered using sieving and separation. It is also found that as the content of copper in the concentrate increa-ses, that of arsenic increase, while zinc and iron contents decrease.

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.79-84
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• 2004

The existing technological schemes for processing rhenium-containing raw materials involve the recovery of Re from solutions, which can be effectively achieved by anion exchange method. The application of anion exchange also allows to study rhenium state in aqueous solutions and to develop analytical control methods. The present work is focused on investigation of ion exchange equilibrium in the analytical system Re(VII)-HCl-$SnCl_2$-KSCN-anion exchanger by means of sorption-desorption method as well as by electron, IR- and diffuse reflection spectroscopy. It was shown that rhenium can be quantitatively recovered from this system. It is proposed to use the sorption-spectroscopic method for Re(VII) determination in aqueous solutions. The calibration curve is linear in the concentration range of 0.5-20.0 mg/L (sample volume is 25.0 mL) and the detection limit is 0.05 mg/L. The presence of Mo(VI), Cu(II), Fe(II, III), Ni(II), Zn(II) as well as $K^+,\;Na^+$ do not hinder the solid-phase determination of rhenium. Rhenium (VII) determination by diffuse reflection spectroscopy was carried out in model solutions as well as in samples of river-derived water and in solutions obtained after the dissolution of spent catalysts.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.541-550
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• 2010

A new $N_4O_3$ heptadentate ligand, N,N'-Bis(2-hydroxybenzyl)-1,3-bis[(2-aminoethyl)amino]-2-propanol(H-BAP 4HCl)was synthesized. The hydrochloric acid salts of Br-BAP 4HCl, Cl-BAP 4HCl, $CH_3O$-BAP 4HCl and $CH_3$-BAP 4HCl containing Br-, Cl-, H-, $CH_3O-$ and $CH_{3^-}$ groups at the para-site of the phenol group of the H-BAP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible and mass spectra. The elemental stepwise protonation constants(${logK_n}^H$) of the synthesized $N_4O_3$ ligands showed six steps of the proton dissociation. The orders of the overall dissociation constants($log{\beta}_p$) of the ligands were Br-BAP < Cl-BAP < H-BAP < $CH_3O$-BAP < $CH_3$-BAP. The orders agreed well with that of Hammett substituent constants($\sigma_p$). The calculated stability constants($logK_{ML}$) between the ligands and transition metal ions agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in Hammestt substituent constants($\sigma_p$). The order of the stability constants between the transition metal ions with the ligands were Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).

• Economic and Environmental Geology
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• v.22 no.3
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• pp.253-266
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• 1989

The Cu-Pb-Zn-Ag hydrothermal vein type deposits which comprise the Dongil and Dong-cheogogsan mines occur within the Cretaceous sedimentary rocks in the Euiseong Basin of the southern Korean peninsula. The ore mineralization is contained within three stage(I,II and III) quartz and calcite veins. Ore minerals occur as dominant chalcopyrite, galena, sphalerite, tetrahedrite and Pb, Ag, Sb and Bi-bearing sulfosalts. Stage I ore minerals were deposited between $400^{\circ}C$ and $200^{\circ}C$ from the fluid with moderate salinities(7.0 to 4.5 eq. wt. % NaCl). Evidence of boiling suggests pressure of less than 150 bars during stage I mineralization. This pressure corresponds to maximum depths of 650 m and 1700 m, respectively, assuming lithostatic and hydrostatic loads. The data on mineralogy, temperature and salinity, together with information on the solubility of Cu complex, suggest that Cu deposition is a result of boiling coupled with declining temperature from $350^{\circ}$ to $250^{\circ}C$ or declining log $a_{o_2}$(from -29.8 to -35.9 atm.)and increasing in pH. Pb, Ag, Sb and Bi-bearing sulfosalts were deposited by cooling and dilution at temperature of less than $250^{\circ}C$ from the ore fluid with less than -35.9 atm. of log $a_{o_2}$.

• Analytical Science and Technology
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• v.10 no.3
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• pp.187-195
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• 1997

Chemically modified electrodes(CMEs) for Ag(I) were constructed by incoporating 1,5,9,13-tetrathiacyclohexadecane([16]-ane-$S_4$) with a conventional carbon-paste mixture composed of graphite powder and nujol oil. Ag(I) ion was chemically deposited onto the surface of the modified electrode with [16]-ane-$S_4$ by immersion of the electrode in the acetate buffer solution(pH=4.5) containing $5.0{\times}10^{-4}M$ Ag(I) ion. And then the electrode deposited with Ag(I) was reduced at -0.3V vs. S.C.E. Well-defined stripping voltammetric peaks could be obtained by scanning the potential to the positive direction. The CME surface was regenerated with exposure to 0.1M $HNO_3$ solution and was reused for the determination of Ag(I) ion. When deposition/measurement/regeneration cycles were 10 times, the response could be reproduced with relative standard deviation of 6.08%. In case of differential pulse stripping voltammetry, the calibration curve for Ag(I) was linear over the range of $5.0{\times}10^{-7}{\sim}1.5{\times}10^{-6}M$. And the detection limit was $2.0{\times}10^{-7}M$. Various ions such as Cd(II), Ni(II), Pb(II), Zn(II), Mn(II), Mg(II), EDTA, and oxalate(II) did not influence the determination of Ag(I) ion, except Cu(II) ion.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.87-105
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• 1991

The purpose of this experiment was to measure the leaking and solubility of commonly used dental restorative materials - Silux plus (CS), Hi-pol (CH), Clearfil F-II, Fissureseal (FS), Glass-Ionomer cement Fuji Type II (GI), Amalgam Cavex 68 (AM), Zinc Phosphate Cement (ZP) and gutta-percha (GP) and investigate the relation between the solubility and marginal leakage. Disc-shape specimens were fabricated with each material and dipped into deionized water, 0.01M lactic acid and 0.005M KOH solution, thus the total ionic concentrations in each solution was measured with ion chromatograph after 1, 3, and 7 days, respectively. For the solubility test, each specimen was immersed in 0.001M and 0.01M lactic acid for 24 hours, respectively and total weight loss was calculated. Also, Zn leaking through the margin of restorations was measured. The obtained results were as follows: 1. The amounts of eluted ion from the eight materials were most in 0.01M lactic acid and least in deionized water. 2. Of the eight materials, the fluoride release was greatest for glass ionomer cement (GI) in 0.01 M lactic acid after 7 days. 3. In analysis of the divalent cation, Mg was eluted most for zinc phosphate cement (ZP) and Ca for Clearfil F-II (CF) in 0.01M lactic acid after 7 days. 4. In analysis of transition metals, Cu and Zn were detected only. 5. The solubility rate of eight materials was greater in 0.01M lactic acid than in 0.001M for 24 hours, for zinc phosphate cement (ZP) the rate was greatest (5.4%) in 0.001M lactic acid, and amalgam least (0.01%). 6. The Zn concentration of restorative material with Z.P.C base was greater in 0.01M lactic acid than in 0.001M lactic acid.

• Current Photovoltaic Research
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• v.1 no.2
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• pp.109-114
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• 2013

$Cu_2ZnSnS_4$ (CZTS) nanoparticles were synthesized by a solvothermal method using copper (II) acetate, zinc acetate, tin chloride, and sulfur in diethylenetriamine solvent. Binary sulfide particles such as CuS, ZnS, SnS, and $SnS_2$ were obtained at $180^{\circ}C$; single-phase CZTS nanoparticles were obtained at $280^{\circ}C$. CZTS nanoparticles with spherical shape and grain size of 40 to 60 nm were obtained at $280^{\circ}C$. In the middle of 180 and $280^{\circ}C$, CZTS and ZnS phases were found. The time variation of reaction at $280^{\circ}C$ revealed that an amorphous state formed first instead of binary phases and then the amorphous phase was converted to crystalline CZTS state; it is different reaction path way from conventional solid-state reaction path of which binary phases react to form CZTS. CZTS films deposited and annealed from single-phase nanoparticles showed porous microstructure and poor adhesion. This indicates that a combination of CZTS and other flux phase is necessary to have a dense film for device fabrication.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.67-82
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• 2002

Objectives: In recent years, extensive focus has been laid on adulteration of herbal medicine with heavy metals. This may be mainly due to soil contamination by environmental pollution. The objective of this study is to identify the contents of various heavy metals in the blood from Ohjeok-san (Wuji-san) Decoction (OD) treated-rats. Methods: For this study, 13 kinds of metals including essential and heavy metals, i.e. A1, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn were analyzed by a slight modification of EP A methods and the following results are obtained. Results: 1. There was no significant difference between the OD-treated groups and control group in liver, kidney, bone, brain and weight, especially no significant difference at the 5th and 10th days in weight and the amount of food intake. 2. The amount of each metal analyzed in the blood were as follows; A1: 2.3~3.07 mg/l, As: 2.90~3.66 mg/l, Cd: 0~0.001 mg/l, Co: 0~0.01 mg/l, Cr: 0.40~043 mg/l, Cu: 0.93~1.88 mg/l, Fe: 414.35~464.46 mg/l, Hg: 0.01 mg/l, Mn: 0.10~0.17 mg/l, Ni: 0.01 mg/l, Pb: 0.03~012 mg/l, Se: 0.73 mg/l, Zn: 3.41~4.13 mg/l by groups, respectively. In control and experimental group, Experimental I and other experimental II, III, IV, and V groups, there were no significant differences. 3. The amount of non-toxic metals (A1, Co, Cu, Fe, Mn, Se, Zn) were $64.1{\pm}7.71{\;}mg/l$ in the control group and 60.70~67.58 mg/l in the experimental groups I, II, III, IV and V. The amount of Toxic metals (As, Cd, Cr, Ag, Pb) were $0.68{\pm}0.21{\;}mg/l$ in the control group and 0.57 ~ 0.66mg/l in the experimental groups. The total amount of metals were 32.35 mg/l in the control group and 30.48~34.12 mg/l in the test groups I, II, III, IV and V, respectively. Conclusions: There was no significant difference of metal concentration in the blood from the OD-treated-rats compared to those of the control group even if higher dosage (1~8 times the dosage for a person) of OD was administered. This may be mainly due to a decoction treatment which contains only supernatants filtered from the herb-mass after boiling. This indicates the legal limitation for metal concentration in herbal medicine must be applied according to different treatment methods of herbal medicine.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.645-652
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• 1991

The stability constants$(K_f)$ of the complexes of some transition and post-transition metal ions (Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), Pb(Ⅱ), Hg(Ⅱ)) with $N_2O_3$-donor macrocyclic ligand, 1,15-diaza-3,4 : 12,13-dibenzo-5,8,11-trioxacyclooctadecane ($NtnOdienH_4$), have been determined by potentiometry in aqueous solution at $25^{\circ}C$. Log $K_f$ values of the complexes were : Co(Ⅱ): 3.83, Ni(Ⅱ) : 4.56, Cu(Ⅱ) : 7.74, Zn(Ⅱ) : 4.98, Cd(Ⅱ) : 3.91, Pb(Ⅱ) : 6.65, and Hg(Ⅱ) : 14.87. The order of stabilities of transition metal complexes was the same as the natural order of stability proposed by Williams-Irving. In post-transition metal complexes, the order of stabilities was Cd(Ⅱ) < Pb(Ⅱ) < Hg(Ⅱ), and the covalent character in metal ion-donor atoms bonds appeared a dominant factor in the stability. In methanol solution, each metal ion forms 1 : 1 complex, while Ni(Ⅱ) ion forms both 1 : 1 and 1 : 2 complexes. It was confirmed by $^1H-$ and $^{13}C-$NMR spectral study that the nitrogen atoms in the ligand were major contributors for the complexation of post-transition metal ions with the ligand. It was shown, by elementry analysis, electrical conductivity and magnetic susceptibility measurements, and spectral analysis, that solid Cu(Ⅱ)-and Zn(Ⅱ)-complexes have a distorted octahedral and a tetrahedral structure, respectively.