• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.53-60
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• 1998

This study examines the effect of pH, temperature, metal ion concentration and culture density on metal biosorption by the nuisance cyanobacterium Microcystis aeruginosa. Ni biosorption was higher at pH 9.2 than at neutral and acidic pH. In contrast the biosorption of Cu and Zn was maximum at pH 7.0. However, biosorption of Zn was difficult to measure at pH values 9.2 and 10.5, owing to the formation of insoluble complexes. All the test metals (Cu, Zn, and Ni) showed maximum biosorption rate at low culture densities of 40 mg dry wt $1^{-1}$. The biosorption of Cu, Zn, and Ni was maximum at $40^{\circ}C$. However, no worthwhile difference in Zn and Ni sorption was noticed at 4 and $29^{\circ}C$ as compared to $40^{\circ}C$. Of these three metals used Microcystis showed a greater binding capacity ($K_{f}$ value=0.84, Freundlich adsorbent capacity) and accelerated biosorption rate for Cu under various environmental conditions. Fitness of mathematical models on metal biosorption by Microcystis confirmed that the biological materials behave in the same way as physical materials. These results suggest that before using a biosorbent for metal recovery, the environmental requirements of the biosorbent must be ascertained.

• 대한화학회지
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• 제50권2호
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• pp.99-106
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• 2006

3-(2-thenoyl) 3-(p-NO2-phenylhydrazone) ethyl pyruvate(I), p-Br(II) 및 p-CH3(III)의 에탄올 용액의 전자흡수 스펙트럼을 조사하여 스펙트럼이 전자 전이에 해당하는 4개의 흡수띠로 구성되어 있음을 알았다. 이들 화합물의 pK 값을 분광광도법 및 pH 측정법으로 조사한 결과, 화합물(I)의 변색 범위는 페놀프탈레인과 유사한 8~10으로, 산-염기 지시약으로 사용될 수 있음을 알았다. 몇 가지 전이원소 (Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), UO2(II), La(III) 및 Zr(IV))와 이들 화합물과의 연속안정도상수를 pH 법으로 조사하여 본 결과, 모든 금속과 몰 비 1:1 및 1:2 (M: L)의 화학양론적 착물을 형성하며, 세 가지 유도체의 pK 값과 착물의 안정도 상수(log K)의 순서는 III > II > I 임을 알았다. 또한 전도도법 적정을 수행하여 이 적정이 금속이온과 리간드를 정량하는데 사용할 수 있음을 알았다.

• 공업화학
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• 제8권1호
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• pp.23-28
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• 1997

활성탄에 의한 암모니아 구리착물의 흡착 특성에 대하여 연구하였다. 활성탄 비표면적을 BET 흡착장치에서 측정하였고, 암모니아수용액에서 암모니아 착물을 이용하여 Cu(II)이온 제거 특성과 활성탄에 의한 착물흡착에서 암모니아착물 형태에 대하여 연구하였다. 실험 결과 비표면적 크기는 mesh No.가 감소할 수록 증가하였고, 활성탄에 의한 Cu(II)이온 흡착은 pH 6 범위가 적합함을 알았다. 또한 암모니아수용액에서 암모니아 구리착물이 활성탄에 흡착되는 형태는 $[Cu(NH_3){_2}]^{2+}$와 $[Cu(NH_3){_3}]^{2+}$로 흡착됨을 알았으며, 암모니아 농도는 $2.25{\times}10^{-4}{\sim}2.25{\times}10^{-3}(mol/{\ell})$ 범위에서 검토하였다.

• 대한화학회지
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• 제44권6호
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• pp.507-512
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• 2000

질산구리와 2,2'-dipyridylbenzylamine(dpb)를 에탄올 용액에서 반응시켜 새로운 구리 착화합물, $Cu(dpb)(NO_3)_2$(1)를 합성하였다. 아세토니트릴 용액에서 재결정하여 단결정을 얻었으며 XRD법을 이용하여 결정 구조를 확인하였다. 결정은 orthorhombic 형태로서 $P2_1/c$ 군에 속하고 그 밖의 자료들은 다음과 같다. a=12.501(9)${\AA}$, b=9.231(10)${\AA}$, c=17.119(6)${\AA}$, ${\alpha}=90^{\circ},\;{beta}=107.33(4)^{\circ},\;{\gamma}=90^{\circ},\;V=1885.8(2){\AA}^3,\;R_1=0.0647,\;_{w}R_2=0.1866$, Z=4. EPR, NMR, UV/VIS, 그리고 IR 등의 분광학적인 확인법에 의하여, 합성된 화합물은 디피리딜아민 유도체를 리간드로 하는 전형적인 상자성 구리(II) 배위 화합물임을 확인하였다.

• 한국토양비료학회지
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• 제19권4호
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• pp.307-314
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• 1986

Sewage Sludge 를 시용하지 않은 토양(W), 6년간 시용한 토양($WS_6$), Sludge와 토양의 혼합물을 1주일동안 incubation한 토양($WS_1$), 그리고 Sewage Sludge(SS)로 부터 추출한 수용성 유기물(WSOF)이 구리(II) 이온과 어떻게 착화합물을 형성하는지를 전자스핀공명분광법(ESR)과 전위차적정법을 이용하여 규명하였다. Cu(II)-WSOF 착화합물은 ESR spectra 상에서 $g_{\perp}$ 값보다 큰 $g_{\amalg}$ 값을 가짐으로서 늘어난 팔면체(elongated octahedron) 배위결합을 하고 있음을 나타내었다. $77^{\circ}K$에서 Cu(II)-SS착물은 anisotropic ESR spectrum을 보인 반면 Cu(II)-W착물은 anisotropic spectrum을 나타내었다. 이러한 결과는 결국 W의 산소공여 리간드가 Cu(II)와 강한 착화합물을 이루는 반면에 SS의 리간드는 Cu(II)와 거의 Chelate를 이루지 않고 있음을 의미한다. 또한 Cu(II)-SS 착화합물의 ESR spectra는 평면상의 네개의 모서리 리간드(예, $COO^-$, $H_2O$, $Cl^-$ 등등)의 각각이 한자리 리간드로서 독립적으로 행동하고 있음을 암시한다. W에서는 방향족 카복실기 같은 산소공여 리간드가 주로 Cu(II)와 결합하고 있는것 같고 SS에서는 Sulfonate, 지방족 카복실기 그리고 질소를 함유하는 리간드가 주요한 결합 site인 것 같다. Cu(II)-SS착화합물과 비교할때 Cu(II)-W로 부터 Cu(II)를 치환하는데 6배정도의 Pyridine 농도가 요구되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권8호
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• pp.1066-1072
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• 2010

In this study, the effects of replacing inorganic copper, zinc and manganese with different levels of organic complexes of the same trace minerals on the lipid peroxidation and antioxidant defense systems in broilers were investigated. Two-hundred Ross-308 one-day-old broiler chickens were placed on controlled diets until 42 d of age. The experimental animals were divided into four groups comprising three experimental groups and one control group, each consisting of 50 chickens. All groups were also divided into five subgroups each containing 10 broiler chicks. The mineral content of the control group diet was controlled using a standard inorganic mineral premix with supplement levels and sources of trace minerals typical of commercial broiler diets according to the National Research Council (NRC) (containing 8 mg Cu as $CuSO_4$, 40 mg Zn as $ZnSO_4$, and 60 mg Mn as MnO, per kg). In the experimental diets, mineral premix was also comprised of inorganic formulations, except for those of Cu, Zn and Mn. Organically-complexed Cu, Zn, and Mn were separately added to the basal diet at 1/3 (L1), 2/3 (L2) and 3/3 (L3) levels with respect to the NRC recommendation, as Bioplex $Cu^{TM}$, Bioplex $Zn^{TM}$, Bioplex $Mn^{TM}$. At the end of the trial, the plasma Zn level significantly increased when the plasma Cu level significantly decreased (p<0.05) in chickens fed at 2/3 and 3/3 levels of organically complexed minerals. The liver trace mineral concentrations were significantly higher in chickens fed inorganic trace minerals in comparison to those fed organically-complexed minerals. The plasma malondialdehyde (MDA) level of experimental chickens was decreased in groups receiving levels of organic Cu, Zn and Mn in comparison to those fed inorganic forms (p<0.01). The erythrocyte superoxide dismutase (SOD) activity was higher in all groups receiving the organic mineral supplements in comparison to those fed inorganic forms (p<0.01). No differences were observed on either the erythrocyte catalase (CAT) activity or the plasma ceruloplasmin (Cp) levels, and the liver MDA levels and liver CAT and SOD activities in any of the groups that received the organic supplements of Cu, Zn, and Mn. It was concluded that supplementation of lower levels of organically-complexed copper, zinc, and manganese instead of their inorganic forms in diets had no negative effects on the antioxidant defense system in broilers.

• 농업과학연구
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• 제46권4호
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• pp.799-811
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• 2019

The aim of this study was to evaluate heavy metal contamination and pollution index of agricultural soils around industrial complexes in the Jeon-Buk Regions of Korea. Soil samples near industrial complexes in 2017 were collected at two depths (0 - 15 and 15 - 30 cm) within a 500- and 1000-meter radius before planting. Eight heavy metals (Arsenic (As), cadmium (Cd), chromium (Cr), Cupper (Cu), nickel (Ni), lead (Pb), mercury (Hg) and zinc (Zn)) and the pollution index (PI), geoaccumulation index (Igeo) and soil pollution index (SPI) were evaluated based on soil contamination warning standard (SCWS). Overall, the heavy metal concentrations were below the SCWS. The PI ranged from 0.1 to 0.9 and categorized into Group 1 which is not polluted with any heavy metals. The average Igeo values of all the soil samples ranged from - 2.56 to 3.22. The Igeo values of Cd and Hg may not represent well the pollution index because the heavy metal concentrations in the soil is lower compared to the SCWS. In fact, based on the heavy metal concentrations, the Igeo for monitored soils should be categorized into Group 1, uncontaminated to moderately contaminated. However, the Igeo of Cd and Hg are classified into heavily contaminated. These results suggest that for calculating the Igeo, the heavy metal concentration and background concentration should be used very carefully if the heavy metal concentration in the soil is lower than the background concentration. SPI for all the soil samples ranged from 0.00 to 0.11 which indicates no heavy metal pollution was observed.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1704-1710
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• 2010

The structure of a 2D grid-like copper(II) complex [Cu$(NCO)_2$(pyz)](pyz=pyrazine) (1) consists of 1D chains of Cu-pyz units connected by double end-on (EO) cyanato bridges. Each Cu(II) ion has a distorted octahedral coordination, completed by the four EO cyanato and two pyrazine ligands. Magnetic interactions through EO cyanato and pyrazine bridges in 1 are discussed on the basis of DFT broken-symmetry calculations at the B3LYP level. For model dicopper(II) complexes I (bridged by cyanato) and II (bridged by pyrazine), electronic structure calculations reproduce very well the experimental couplings for the S = 1/2 ferromagnetic and antiferromagnetic exchange-coupled 2D system: the calculated exchange parameters J are +1.25 $cm^{-1}$ and -3.07 $cm^{-1}$ for I and II, respectively. The $\sigma$ orbital interactions between the Cu $x^2-y^2$ magnetic orbitals and the nitrogen lone-pair orbitals of pyrazine are analyzed from the viewpoint of through-bond interaction. The energy splitting of 0.106 eV between two SOMOs indicates that the superexchange interaction should be antiferromagnetic in II. On the other hand, there are no bridging orbitals that efficiently connect the two copper(II) magnetic orbitals in I because the HOMOs of the basal-apical NCO bridge do not play a role in the formation of overlap interaction pathway. The energy separation in the pair of SOMOs of I is calculated to be very small (0.054 eV). This result is consistent with the occurrence of weakly ferromagnetic properties in I.

• 대한화학회지
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• 제8권2호
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• pp.62-64
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• 1964

The cation exchange chromatographic studies for the analysis of transition metals have been described. The quantitative separation of a mixture of Fe(Ⅲ), Cu(II), Zn(II), Ni(II), Cd(II), Co(II) and Mn(II) has been obtained by elution, through a 28cm column of the resin, Dowex 50 ${\times}$ 4 (100∼200 mesh), using 0.45 M $NaNO_3$+0.05 M Na-tartrate solution as eluent, starting with the eluent of pH 3.5, followed stepwise by pH 4.0 and 4.5. A comparison between the calculated and the observed peak positions in the elution curve has been shown. The relative stability constants for tartrate complexes of some transition metals have been calculated by using distribution ratios obtained in this separation procedure.

• Bulletin of the Korean Chemical Society
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• 제22권4호
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• pp.379-382
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• 2001

A new ligand containing the long aliphatic hydrocarbon chain, dipyridylstearylamine (dps) and its copper(Ⅱ) complex, Cu(dps)(NO3)2 have been prepared. The copper complex was characterized structurally and spectroscopically. The XRD crystal structure of the copper complex reveals that copper is octahedrally coordinated by dps and two nitrato ligands. The nitrato groups ligate asymmetrically to the copper. Crystal data are P1bar, a=8.249(2), b=10.416(3), $c=20.915(4)\AA$, $\alpha=86.54(2)$, $\beta=84.026(2)$, $\gamma=72.32(2)^{\circ}$, V=1702.7(7) $\AA3$ , Z=2, ${\lambda}$(Mo $K\alpha)=0.71073\AA$, $\mu=0.689$ mm-1 , T=293(2) K, R=0.0560 for 3529 reflections. The dps and the copper complex are stable in the air and the copper complex exhibits features of typical of other copper(Ⅱ) complexes containing dipyridylamine-based ligand.