• Title/Summary/Keyword: Iron concentration

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Ecophysiological Responses and Subsequent Recovery of the Olive Flounder, Paralichthys olivaceus Exposed to Hypoxia and Iron II. Survival, Metabolic and Histological Changes of the Olive Flounder Exposed to Iron (빈산소와 철에 대한 넙치 (Paralichthys olivaceus)의 생태생리적 반응 및 회복 II. 철에 노출된 넙치의 생존, 대사 및 조직학적 변화)

  • KANG Ju-Chan;LEE Jung-Sick;JEE Jung-Hoon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.6
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    • pp.699-705
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    • 1999
  • The effects of iron on gill tissue and metabolic rate represented by oxygen consumption of olive flounder, Paralichthys olivaceus were determined. The effects were further studied by means of survival rate of the fish exposed to a serial concentrations of iron. The olive flounder exposed to iron concentrations over 0.93 mg/$\ell$ showed curvature and terminal clubbing of gill lamellae at 2 weeks post-exposure. In iron concentration 4.89 mg/$\ell$, gill of the fish were seriously damaged just after 2 weeks, showing hyperplasia of filament epithelia, deformation of lamella epithelia, chloride cell damage, and separation of lamella epithelial layer, Gills exposed to 9.78 mg/$\ell$ iron concentration resulted in fusion and necrosis of the lamellae after 2 weeks. Significant decreases of metabolic rate of the fish were observed after 4 weeks at iron concentration 0,93 mg/$\ell$ and after 2 weeks at iron concentrations over 4.89 mg/$\ell$. Survival rate of the olive flounder decreased significantly after 4 weeks at the iron concentration over 4.89 mg/$\ell$. These results lead us to conclude that, as far as the iron effects are concerned, its concentrations should not exceed at least more than 0.93 mg/$\ell$ in the fish farm and coastal waters for normal growth of the olive flounder.

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Atmospheric Effects on Corrosion of Iron in Borate Buffer Solution (Borate 완충용액에서 철의 부식에 대한 대기의 영향)

  • Kim, Hyun-Chul;Kim, Younkyoo
    • Journal of the Korean Chemical Society
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    • v.56 no.6
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    • pp.673-678
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    • 2012
  • Using potentiodynamic and linear polarization method, the atmospheric effect on the corrosion of iron in borate buffer solution was investigated. The corrosion of iron was heavily influenced by the degree of oxygen concentration. The supply of reduction current was increased by the reduction of dissolved oxygen, and the corrosion potential of iron was shifted to the positive side. The $OH^-$ ion, which was produced through the reduction of either water or oxygen, significantly increased the $OH^-$ ion concentration inside of the electrical double layers of iron electrode, and facilitated the adsorption of $OH^-$ ion on the surface of the iron electrode. The adsorption of $OH^-$ ion on the iron electrode can be explained either by Langmuir isotherm or by Temkin logarithmic isotherm.

Innovative Remediation of Arsenic in Groundwater by Nano Scale Zero-Valent Iron

  • Kanel, Sushil-Raj;Kim, Ju-Yong;Park, Heechul
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.87-90
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    • 2003
  • This research examines the feasibility of using laboratory-synthesized nano scale zero-valent iron particles to remove arsenic from aqueous phase. Batch experiments were performed to determine arsenic sorption rates as a function of the nano scale zero-valent iron solution concentration. Rapid adsorption of arsenic was achieved with the nano scale zero-valent iron. Typically 1 mg $L^{-1}$ arsenic (III) was adsorbed by 5 g $L^{-1}$ nano scale zero-valent iron below the 0.01 g $L^{-1}$ concentration within 7min. The kinetics of the arsenic sorption followed pseudo-first-order reaction kinetics. Observed reaction rate constants ( $K_{obs}$) varied between 11.4 to 129.0 $h^{-1}$ with respect to different concentrations of nano scale zero-valent iron. A variety of analytical techniques were used to study the reaction products including HGAAS (hydride generator atomic adsorption spectrophotometer), SEM (scanning electron microscopy) and TEM (transmission electron microscopy). Our experimental results suggest novel method for efficient removal of arsenic Iron groundwater.r.

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The Persimmon Dye with Experiment of Changing Concentration and Iron-dye Process, its Application Possibility for Textile Design (감염색의 농도변화와 매염효과를 통해본 천연염색 디자인)

  • Lee, Soon-Deuk
    • Fashion & Textile Research Journal
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    • v.10 no.6
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    • pp.822-826
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    • 2008
  • The data for application of mordanting is shown in this experiment by researching dying properties of iron-dye process and concentration changes using persimmon. The strength of persimmon-dying fabrics was controlled by diluting persimmon dye with water and iron mordanting showed the possibility of textile design. The experiments were performed with various conditions processed with iron mordanting liquid by adding water to persimmon-dying liquid and drying well. The most dark color of fabric is observed with the pure persimmon dying without adding water. As the adding water is increased, the color of the fabric is getting lighter with the amount of adding water. After process of iron mordanting, dark color of the fabric turns into dark grey and light color turns into light grey. The possibility of persimmon dying with fabric can be applied in the design of textile with deepened color.

The Nutritional Status of Iron, Magnesium and the Effects of Iron Supplementation on Serum Iron and Magnesium Concentrations of Pregnant Korean Women (임신부의 일상 식이 중 철, 마그네슘 영양상태와 철 보충제의 복용이 혈청 철, 마그네슘의 함량에 미치는 영향)

    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.6
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    • pp.495-506
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    • 2000
  • The purpose of this study was to assess the nutritional status of iron and magnesium and the effect of von supplementation during 8 weeks(from 20 to 28 weeks of gestation) on serum iron and magnesium status of 31 pregnant women in Kyunsin area. The age, weight, and height of the subjects before pregnancy were investigated by questionnaires. At 20 and 28 weeks of gestation, data for food and nutrient intake were obtained by questionnaires and serum sample was obtained. According to the frequency of iron supplementation, subjects were divided into two groups(4$\geq$/wk) The mean iron supplementation of 5 $\geq$/wk group(63.mg/day) was significantly higher than 4$_2$ intakes were much less than the Korean RDA. Especially, calcium, iron and magnesium intakes showed half the levels compared with Korean RDA. At 28 weeks of gestation the serum total protein(p<0.001), albumin(p<0.01) and globulin(p<0.001) were significantly decreased. Total iron binding capacity(TIBC) was significantly increased(P<0.001), but serum ferritin(p<0.01) and magnesium(p<0.01) concentrations were significantly decreased. However, even 28 weeks of gestation 5$\geq$/wk group showed higher serum iron and ferritin concentration and lower TIBC than 4$\geq$/wk group. Therefore, iron supplementation should be conducted with concerning the mineral balance like magnesium.

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Iron Oxidation using Limestone in Groundwater (석회석을 이용한 지하수 철분 산화)

  • Sim, Sang Jun;Kang, Chang Duk;Lee, Ji Hwon;Cho, Young Sang
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.1
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    • pp.73-81
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    • 2000
  • The removal of ferrous iron (Fe(II)) in groundwater is generally achieved by simple aeration or the addition of oxidizing agent. Aeration followed by solid-liquid separation is the most commonly used as physico-chemical treatment method for iron removal. In general aeration has been shown to be very efficient in insolubilizing ferrous iron at the pH level greater than 6.5. In this study pH was maintained over 6.5 using limestone granules under constant aeration to oxidize ferrous iron. In batch experiments, oxidation rate of ferrous iron was investigated under different conditions including limestone granule size. initial concentration of the ferrous iron, pH, temperature and ionic strength in groundwater. The pH in groundwater was presumed as the most important factor determining oxidation rate of ferrous iron. According as the size of the limestone granules decreased, the pH of the iron contaminated water increased quickly and oxidation of the ferrous iron was achieved immediately too. The oxidation rate of the ferrous iron was found to be proportion to initial concentration of the iron contaminated water, temperature and ionic strength, respectively.

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Atmospheric Polycyclic and Nitropolycyclic Aromatic Hydrocarbons in an Iron-manufacturing City

  • Hayakawa, Kazuichi;Tang, Ning;Morisaki, Hiroshi;Toriba, Akira;Akutagawa, Tomoko;Sakai, Shigekatsu
    • Asian Journal of Atmospheric Environment
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    • v.10 no.2
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    • pp.90-98
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    • 2016
  • Total suspended particulates (TSP) in the atmosphere were collected for 2 weeks during winter in Muroran, Hokkaido, Japan, a typical iron-manufacturing city. The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in TSP were determined by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. No relationship was observed between the atmospheric PAH and NPAH concentration, or the atmospheric PAH and TSP concentration. However, there was a tendency that the atmospheric PAH concentration was higher when the wind blew from the coke-oven plant. Furthermore, the concentration ratios of 1-nitropyrene to pyrene, which is a suitable indicator of the contribution made by automobiles and coal combustion systems to urban air particulates, were smaller in Muroran and the values were close to those observed in particulates from coal combustion systems. Therefore, these results show that the PAH and NPAH compositions for Muroran are characteristic of an iron-manufacturing city.

Reduction of Dissolved Fe(III) by As(V)-tolerant Bacteria Isolated from Rhizosphere Soil

  • Khanal, Anamika;Song, Yoonjin;Cho, Ahyeon;Lee, Ji-Hoon
    • Korean Journal of Environmental Agriculture
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    • v.40 no.1
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    • pp.67-72
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    • 2021
  • BACKGROUND: Biological iron redox transformation alters iron minerals, which may act as effective adsorbents for arsenate [As(V)] in the environments. In the viewpoint of alleviating arsenate, microbial Fe(III) reduction was sought under high concentration of As(V). In this study, Fe(III)-reducing bacteria were isolated from the wild plant rhizosphere soils collected at abandoned mine areas, which showed tolerance to high concentration of As(V), in pursuit of potential agents for As(V) bioremediation. METHODS AND RESULTS: Bacterial isolation was performed by a series of enrichment, transfer, and dilutions. Among the isolated strains, two strains (JSAR-1 and JSAR-3) with abilities of tolerance to 10 mM As(V) and Fe(III) reduction were selected. Phylogenetic analysis using 16S rRNA genesequences indicated the closest members of Pseudomonas stutzeri DSM 5190 and Paenibacillus selenii W126, respectively for JSAR-1 and JSAR-3. Ferric and ferrous iron concentrations were measured by ferrozine assay, and arsenic concentration was analyzed by ICP-AES, suggesting inability of As(V) reduction whereas ability of Fe(III) reduction. CONCLUSION: Fe(III)-reducing bacteria isolated from the enrichments with arsenate and ferric iron were found to be resistant to a high concentration of As(III) at 10 mM. We suppose that those kinds of microorganisms may suggest good application potentials for As(V) bioremediation, since the bacteria can transform Fe while surviving under As-contaminated environments. The isolated Fe(III)-reducing bacterial strains could contribute to transformations of iron minerals which may act as effective adsorbents for arsenate, and therefore contribute to As(V) immobilization

A Study on the Carburization of iron (철의 침탄기구에 대한 연구)

  • 권호영;조통래;권혁무
    • Journal of the Korean Professional Engineers Association
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    • v.20 no.4
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    • pp.5-11
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    • 1987
  • The experiment was carried out for the purpose of studying the carburization of pure iron ingot and sintered iron powder by solid carbon in the atmosphere of $N_2$ gas. The velocity of carburization was estimated by the diffusion coefficient D calculated by carburization equation. The results obtained were as follows ; 1. The briqueted sample of iron fine powder which made by higher pressure, carburization depth and carbon concentration were increased as much, and pure iron shelved the maximum value. 2, The higher the carburization temperature, carburization depth and carbon concentration were increased, and the melting zone which had 3.0~3.3%C at the interface of carburization was formed at 130$0^{\circ}C$. As the pure iron ingot was carburized, the diffusion coefficient D of carbon were 0.211$\times$$10^{-6}$$\textrm{cm}^2$ㆍsec$^{-1}$ at 120$0^{\circ}C$ and 0.391$\times$$10^{-6}$$\textrm{cm}^2$ㆍsec$^{-1}$ at 130$0^{\circ}C$, respectively. 4. As the sintered iron powder was carburized at the pressure of 4 ton/$\textrm{cm}^2$, the diffusion coefficient of carbon were 0.157$\times$$10^{-6}$$\textrm{cm}^2$ㆍsec$^{-1}$ at 120$0^{\circ}C$ and 0.103$\times$$10^{-5}$$\textrm{cm}^2$ㆍsec$^{-1}$ at 130$0^{\circ}C$, respectively.

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Study on the Prevalence of Iron-deficient Anemia in Korean Preschool Children (학령 전 아동의 철 결핍성 빈혈 영양 상태 판정에 관한 연구)

  • Shin, Kyung-Ok
    • The Korean Journal of Food And Nutrition
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    • v.27 no.3
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    • pp.406-413
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    • 2014
  • The objective of this study was to identify the nutritional risk factors by blood analysis, in 1,083 preschool children of age 3 to 6 years. The frequency of anemic children was 7.3% with Hb<11.1 g/dL, 29.9% with ferritin<20 ng/mL, and 16.7% with transferrin Fe saturation(%)<15%. The prevalence of anemia in these children were 12.8% for those with MCV<79 fL, and it was 71% for those with TIBC> $400{\mu}g/dL$. Serum ferritin concentration was 20 ng/mL in the normal children. Thirty two percent of the children had anemia with Hb<12 g/dL, which is below the normal range of Hb. Exactly 15.4% of the children had serum Fe concentration of $60{\mu}g/dL$. The transferrin Fe saturation of the children (16.3%) was >15%. The serum ferritin concentration showed low correlations with Hb, Fe, transferrin Fe saturation, and MCV. The transferrin Fe saturation, higher Hb concentration, MCV, and Hct values were increased significantly. Consequently, iron-deficiency anaemia was thus defined as having Hb concentration <12 g/dL accompanied by ferritin concentration <20 ng/mL or Hct <33%.