• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.541-548
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• 2009

Iron coated media (activated carbon, sand and starfish) were prepared at pH 4 and applied for the treatment of landfill leachate containing organic compounds and soluble metal ions such as $Zn^{2+},\;Cu^{2+},\;Mn^{2+}$ in batch and column experiment. The amount of iron coated in media was analyzed with EPA 3050B method. The removal efficiency of metal ions and phenol was compared with iron coated media. The amount of iron coated in Fe-AC and ICS(iron coated sand) were 1,612 mg/kg and 1,609 mg/kg, respectively, while it was higher with 1,768 mg/kg in ICSF(iron coated starfish). The result of batch study represent the highest removal efficiency in the treatment of wastewater using iron coated starfish. In column study, the removal efficiency of phenol and metal ions was higher in multi-layered system of ICS, Fe-AC and ICSF compared to single layered system. Breakthrough time in the effluent was relatively enhanced for $Cu^{2+}$ and $Zn^{2+}$ in multi-layered system while the removal efficiency of $Mn^{2+}$ were not varied much. Therefore, multi-layered system was identified as the better system for the treatment of wastewater containing of metal ions and organic compound.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.68-76
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• 2002

In this study, we have investigated the geochemical behavior and fate of heavy metals in acid rock drainage (ARD). The ARD was collected from the area of the former Dongrae pyrophyllite mine. The Dongrae Creek waters were strongly acidic (pH : 2.3~4.2) and contained high concentrations of $SO_4$, Al, Fe, Mn, Pb, Cu, Zn, and Cd, due to the influence of ARD generated from weathering of pyrite-rich pyrophyllite ores. However, the water quality gradually improved as the water flows downstream. In view of the change of mole fractions of dissolved Fe, Al and Mn, the generated ARD was initially both Fe- and AA-ich but progressively evolved to more Al-rich toward the confluence with the uncontaminated Suyoung River. As the AR3 (pH 2.3) mixed with the uncontaminated waters (pH 6.5), the pH increased up to 4.2, which caused precipitation of $SO_4$-rich Fe hydroxysulfate as a red-colored, massive ferricrete precipitate throughout the Dongrae Creek. Accompanying the precipitation of ferricrete, the Dongrae Creek water progressively changed to more Al-rich toward downstream sites. At the mouth of the Dongrae Creek, it (pH 3.4) mixed with the Suyoung River (pH 6.9), where pH increased to 5.7, causing precipitation of Al hydroxysulfate (white precipitates). Neutralization of the ARD-contaminated waters in the laboratory caused the successive formation of Fe precipitates at pH<3.5 and Al precipitates at higher pH (4~6). Manganese compounds were precipitated at pH>6. The removal of trace metals was dependent on the precipitation of these compounds, which acted as sorbents. The pHs for 50% sorption ($pH_{50}$) in Fe-rich and Al-rich waters were respectively 3.2 and 4.5 for Pb, 4.5 and 5.8 for Cu, 5.2 and 7.4 for Cd, and 5.8 and 7.0 for Zn. This indicates that the trace metals were sorbed preferentially with increasing pH in the general order of Pb, Cu, Cd, and Zn and that the sorption of trace metals in Al-rich water occurred at higher pH than those in Fe-rich water. The results of this study demonstrated that the partitioning of trace metals in ARD is not only a function of pH, but also depends on the chemical composition of the water.

• Journal of Nutrition and Health
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• v.32 no.3
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• pp.248-258
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• 1999

This study examined the effect of excess loading of calcium (Ca)and iron(Fe) on the bioavailability of minerals in both normal and Ca-and Fe-deficient rats. Three-week-old male rats were divided into four groups and fed experimental diets for six weeks, containing either normal (0.5%) or high(1.5%) Ca and normal (35ppm) or high (350ppm)Fe. Likewise, three-week-old male rats were first fed a Ca-and Fe-deficient diet for three weeks, and then fed one of four experimental diets for additional three weeks. In both normal and Ca-and Fe-deficient rats, ca contents of serum, liver, kidney and femur were not significantly affected by dietary Ca and Fe levels. Apparent Ca absorption(%) decreased in rats fed a high Ca diet regardless of dietary Fe levels. Magnesium(Mg) contents of serum, liver and femur significantly decreased in rats fed a high Ca diet. Fe contents of serum and liver significantly increased in rats fed a high-Fe diet, but decreased in rats fed a high Ca diet. Fe content of serum and liver significantly increased in rate fed a high-Fe diet, decreased in rats fed a high-Ca diet. Apparent Fe absorption increased in rats fed a high-Fe diet, and decreased in rats fed a high-Ca diet in Ca-and Fe-deficient rats, but dietary Ca did not seem to affect Fe absorption in normal rats. Phosphorus(P) contents of serum and femur were not significantly affected by dietary Ca and Fe levels in both normal and Ca-and Fe-deficient rats. Serum copper(Cu) decreased in rats fed a high-Fe diet, while serum zinc(Zn) decreased in rats fed a high-Ca diet in normal rats. Cu contents of liver, and Zn contents of serum and liver decreased in rats fed a high-Fe diet in Ca-and Fe-deficient rats. There results suggest that a dietary overload of Ca and Fe in both normal and Ca-and Fe-deficient rats may decrease mineral bioavailability leading to potential health problems.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.90-97
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• 2010

An experiment was conducted to evaluate the effects of low concentrations of organic and inorganic dietary trace minerals on broiler performance and trace mineral digestibility along the small intestine of 35-day-old broiler chickens reared under floor-pen conditions. Eight hundred male, day-old Cobb broiler chickens were randomly allocated to 4 dietary treatments (25 birds per pen with 8 replicates per treatment). Broilers fed diets supplemented with 4, 20, 40 and 30 mg/kg, respectively, of Cu, Fe, Mn and Zn from organic chelates and inorganic salts achieved the same body weight gain as those supplemented at the NRC levels (8 mg Cu, 40 mg Fe, 60 mg Mn and 40 mg Zn/kg, respectively) from inorganic salts. However, birds fed a control diet without any supplementation at dietary levels of 7.4-8.8, 60.1-69.2, 14.6-15.4 and 19.1-20.6 mg/kg of Cu, Fe, Mn and Zn, respectively, had decreased feed intake and growth rate. There was no significant difference in the digestibility of Cu in all regions of the small intestine. Throughout the small intestine the apparent absorption of Mn from both organic and inorganic sources was small, whereas the digestibility of Zn seemed to be more complex, exhibiting differences in the apparent absorption due to both mineral source and intestinal site. Therefore, the digestibility of organic Zn was improved (p<0.01) in the ileum compared to inorganic Zn. The digestibility of Zn in the duodenum was smaller (p<0.05) than that in the ileum.

• Journal of Environmental Science International
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• v.25 no.8
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• pp.1143-1153
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• 2016

Plant biomass, photosystem II (PSII) photochemical activity, photosynthetic function, and zinc (Zn) accumulation were investigated in a sorghum-sudangrass hybrid (Sorghum bicolor ${\times}$ S. sudanense) exposed to various Zn concentrations to determine the elimination capacity of Zn from soils. Plant growth and biomass of the sorghum-sudangrass hybrid decreased with increasing Zn concentration. Symptoms of Zn toxicity, i.e., withering and discoloration of old leaves, were found at Zn concentrations over 800 ppm. PSII photochemical activity, as indicated by the values of $F_v/F_m$ and $F_v/F_o$, decreased significantly three days after exposure to Zn concentrations of 800 ppm or more. Photosynthetic $CO_2$ fixation rate (A) was high between Zn concentrations of 100-200 ppm ($22.5{\mu}mol$ $CO_2{\cdot}m^{-2}{\cdot}s^{-1}$), but it declined as Zn concentration increased. At Zn concentrations of 800 and 1600 ppm, A was 14.1 and $1.8{\mu}mol$ $CO_2{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The patterns of stomatal conductance ($g_s$), transpiration rate (E), and water use efficiency (WUE) were all similar to that of photosynthetic $CO_2$ fixation rate, except for dark respiration ($R_d$), which showed an opposite pattern. Zn was accumulated in both above- and below-ground parts of plants, but was more in the below-ground parts. Magnesium (Mg) and iron (Fe) concentrations were significantly low in the leaves of plants, and symptoms of Mg or Fe deficiency, such as a decrease in the SPAD value, were found when plants were treated with Zn concentrations above 800 ppm. These results suggest that the sorghum-sudangrass hybrid is able to accumulate Zn to high level in plant body and eliminate it with its rapid growth and high biomass yield.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.274-279
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• 2006

To synthesize ZnO colloidal solution by a sol-gel process, zinc acetate ($C_{4}H_{6}O_{4}Zn{\cdot}2H_{2}O{\cdot}0.2\;mol$) and lithium hydroxide ($LiOH{\cdot}H_{2}O{\cdot}0.14\;mol$) in the ethanol were added to the solution containing a dispersing agent, hydroxypropyl cellulose (HPC). The nanosize and physical shape of the synthesized ZnO particles were determined by HPC acting as the dispersing agent. Nanosized ZnO particles were also obtained by a precipitation method based on zinc-2-ethylhexagonate. The precipitates were characterized by DLS, XRD, FE-SEM, and UV-vis. As the results, the ZnO colloids tend to self-assemble into a well-ordered hexagonal close-packed structure. The ZnO nanoparticles have an average diameter of nearly 40 nm with a narrow size distribution.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.51.2-51.2
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• 2009

본 실험에서는 레이저 간섭 리소그래피를 이용한 2차원 나노 패턴을 형성하였고, 수열합성법을 이용하여 90 도에서 ZnO 나노 기둥을 ZnO/Si 기판 상에 제작 하였다. ZnO 버퍼층은 스퍼터를 이용하여 200도, Ar 분위기에서 증착 하였으며, 레이저 간섭 리소그래피를 이용하여 두 번의 노광을 통해 2차원 나노 패턴을 형성하였다. 먼저, 최적화된 포토레지스트를 ZnO/Si 기판 위에 도포하고, 2500rpm에서 30초간 스핀코팅 한 후, 첫번째 노광을 실시 하였고, ZnO/Si 기판을 회전시켜 첫번째 노광과 교차 시킨 다음 두 번째 노광을 통해 교차하는 부분만 현상되도록 하였다. 기판의 회전 및 기판과 입사 레이저 사이의 각도를 조절하여 제작된 나노 패턴의 종류는 square lattice, centered rectangular lattice, oblique lattice, hexagonal lattice, rectangular lattice, 5가지로, 2차원의 모든 격자를 제작 하였다. 저온 수열합성법에서는 Na citrate를 형상제어제 (surfactant ions)로 사용하여 ZnO 나노 기둥을 형성하였다. $NH_4OH$를 이용하여 용액의 pH를 조절하였고, Zn nitrate hexahydrate를 Zn의 원료 물질로 사용하였다. 2차원 나노 패턴의 3차원 형태는 Atomic force microscopy (AFM, Veeco instruments, USA)를 이용하여 접촉 모드에서 관찰하였고, ZnO 나노 구조는 주사 전자 현미경 (FE-SEM, Model: JSM-6701F, Tokyo, Japan) 를 통하여 분석 하였다. 나노 패턴의 AFM 분석 결과 ZnO/Si 기판상에 포토레지스트가 주기적인 배열을 가지는 것을 확인하였고, ZnO/Si 기판상에 포토레지스트가 완전히 현상된 부분이 일정한 배열을 가지는 것을 확인하였다. 포토레지스트가 현상되어 기판의 표면이 드러난 부분의 크기는 약 250nm로 측정되었다. ZnO 나노 구조의 FE-SEM 분석 결과, 각각의 나노 구조가 나노패턴 중 완전히 현상된 부분만을 통하여 성장되었다는 것을 확인하였고, 형상 제어제로 사용된 Na citrate의 첨가 여부에 따라 나노 구조의 모양이 변화되었다는 것을 알 수 있었다. Na citrate 가 첨가된 나노 기둥의 경우 약 500nm의 길이를 가지는 하나의 기둥 형태로 성장하였다는 것을 확인하였다.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.515-523
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• 1999

Nine trace metals (Zn, Fe, Al, Pb, Mn, Cu, Ni, Cr, and Cd) and Se concentrations were determined in organs and tissues(muscle, bone, kidney, liver and skin) of the striped field mice, Apodemus agrarius collected at Daejeo-dong, Pusan city and the Sorak Mt., Kangwon Province. All the trate elements were detected from all the mice examined. As for the metal concentrations in the mice from Daejeo-dong, Zn, Fe, Al, Mn, Ni and Cr were significantly higher than those in Sorak Mt.(p<0.05), suggesting that pesticides including Zn and factory wastes containing several metals might contaminated the environment of Daejeo-dong. As regards the element concentrations in each organ and tissue, Fe, Al, Pb, Mn, Cu, Cr and Cd concentrations were high in liver or kidney; Zn in skin and bone; Ni in bone, skin and kidney; and Se in muscle, liver and skin in all the mice examined. There were significant differences(p<0.05) between juveniles and adults in average concentration of metals(Zn, Fe, Pb, Mn, Ni, and Cd) in every organs and tissues of mice collected at Daejeo-dong. Much higher average levels of metals in juveniles indicate that considerable burdens fo metals might be transferred through the placenta. However, there were no significant differences between males and females, and between young and old adults in average metal concentrations, which suggests that the mice might accumulate the metals during their life time, although they might excrete the metals not only through reproductive activities, such as parturition, lactation and ejaculation of semen, but also through molting, judging from higher accumulating ratios of most metals in skin of adults than of juveniles.

• Resources Recycling
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• v.9 no.4
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• pp.3-15
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• 2000

Reduction of Electric Arc Furnace dust with carbon (graphite) was studied at the temperature range of $800^{\circ}C$ to $1100^{\circ}C$ in Ar gas atmosphere. The briquetted dust with graphite powder was heated in a vertical tube furnace for given reaction time and Quenched in Ar gas atmosphere. It was found that initially the reduction of Zn was chemically controlled and the activation energy was about 120 KJ/mole. Because the almost all of Pb was removed with Cl in the form of $PbCl_2$, it is considered that Pb is removed by chloride reduction. Cu was vaporized as a chloride up to 30% of its original content, but the remaining of Cu would be accumulated with the reduced iron. and also, Cd was removed completely within 15 min. at $1000^{\circ}C$.

• Ocean Science Journal
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• v.41 no.1
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• pp.43-51
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• 2006

Concentration and distribution of Fe, Zn, Cu, Cd, Mn, Pb, Ni among subcellular fractions (cellular membrane structures and cytosol) and Zn, Cu, Cd among cytoplasmic proteins in the kidney and digestive gland of mussel Modiolus modiolus living along a polymetallic concentration gradient were studied. It was found in the kidney of M. modiolus from contaminated sites that the Fe percent increased in the "membrane" fraction, whereas Zn, Pb, Ni and Mn percent increased in the cytosol compared to the kidney of the control mussel. Note kidney cytosol of M. modiolus from clean and contaminated sites sequestered major parts of Cu and Cd. In the digestive gland of M. modiolus from contaminated sites Fe, Zn, Cd, Mn, Ni percent increased in the "membrane" fraction, whereas Cu, Pb percent increased in the cytosol compared to digestive gland of control mussel. Gel-filtration chromatography shows kidney of M. modiolus contains increased metallothionein-like protein levels irrespective of ambient dissolved metal concentrations. It was shown that the metal detoxification system in the kidney and digestive gland of M. modiolus was efficient under extremely high ambient metal levels. However, under complex environmental contamination in the kidney of M. modiolus, the metal detoxification capacity of metallothionein-like proteins was damaged.