• Title/Summary/Keyword: Ferrous iron oxidation

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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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Preparation and Characterization of Liposome for Iron-Fortified Food Additive (철분 강화 식품첨가제용 리포좀의 제조 및 특성)

  • 이종우;전수진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.5
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    • pp.864-868
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    • 2004
  • Iron is an essential ingredient for all metabolism in a living body However, because of the very low content of the iron in foods, many researches have been performed about iron-fortified food additives. We developed an iron-fortified food additive using the liposome that contain ferrous sulfate and hemin. For preventing the autoxidation of the ferrous sulfate, ascorbic acid was applied. Also, to prevent the oxidation of the liposome induced by the added ferrous sulfate and/or hemin, $\alpha$ -tocopherol was additionally applied. Though the effect of the added aqueous ascorbic acid did not show the antioxidative activity on the liposome containing ferrous sulfate and/or hemin, the added $\alpha$ -tocopherol in the phospholipid bilayer could retard the oxidation of the liposome. These results support that the liposome containing ferrous sulfate, hemin and ascorbic acid with the incorporated $\alpha$ -tocopherol could be applied in the food industry as an iron-fortified additive.

Effect of Sterilizing Method on the Quality Change of Iron Fortified Market Milk during Storage (살균방법이 철분강화 우유의 저장중 품질변화에 미치는 영향)

  • 김윤지;김기성
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.4
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    • pp.755-759
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    • 1999
  • To evaluate the effect of sterilizing method on the quality of iron fortified market milk, HTST(high temperature, short time) or LTLT(low temperture, long time) method was adopted after addition of 100ppm ferrous sulfate, ferric citrate, ferric ammonium citrate, or ferrous lactate in market milk. Sterilized iron fortified market milk was stored at 4oC and then pH, lipid oxidation, color change, and sensory quality were observed. The range of pH change in iron fortified market milk sterilized by HTST or LTLT was 6.51~6.74. The order of pH was control>ferric ammonium citrate>ferrous lactate>ferrous sulfate>ferric citrate. Oxygen consumption of ferric ammonium citrate and ferric citrate was lower than ferrous lactate and ferrous sulfate. This trend was same in HTST and LTLT method, but generally oxygen consumption was lower in iron fortified market milk sterilized by LTLT method than by HTST. In total color change, ferrous lactate treatment was closer to control than other treatments. Also sensory characteristics of ferrous lactate treatment was showed better quality than other treatment. From these results, LTLT method was more suitable than HTST method for iron fortified market milk and ferrous lactate was comparably suitable among iron salts used in this study.

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Effect of Batch Melting Temperature and Raw Material on Iron Redox State in Sodium Silicate Glasses

  • Mirhadi, Bahman;Mehdikhani, Behzad
    • Journal of the Korean Ceramic Society
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    • v.48 no.2
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    • pp.117-120
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    • 2011
  • In this study, the redox state of iron in sodium silicate glasses was varied by changing the melting conditions, such as the melting temperature and particle size of iron oxide. The oxidation states of the iron ion were determined by wet chemical analysis and UV-Vis spectroscopy methods. Iron commonly exists as an equilibrium mixture of ferrous ions, $Fe^{2+}$, and ferric ions $Fe^{3+}$. In this study, sodium silicate glasses containing nanoparticles of iron oxide (0.5% mol) were prepared at various temperatures. Increase of temperature led to the transformation of ferric ions to ferrous ions, and the intensity of the ferrous peak in 1050 nm increased. Nanoparticle iron oxide caused fewer ferrous ions to be formed and the $\frac{Fe^{2+}}{Fe^{3+}}$ equilibrium ratio compared to that with micro-oxide iron powder was lower.

Degradation of Phenol with Fenton-like Treatment by Using Heterogeneous Catalyst (Modified Iron Oxide) and Hydrogen Peroxide

  • Lee, Si-hoon;Oh, Joo-yub;Park, Yoon-chang
    • Bulletin of the Korean Chemical Society
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    • v.27 no.4
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    • pp.489-494
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    • 2006
  • Goethite, hematite, magnetite and synthesized iron oxide are used as catalysts for Fenton-type oxidation of phenol. The synthesized iron oxides were characterized by X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR). The catalytic activity of these materials is classified according to the observed rate of phenol oxidation. The effectiveness of the catalysts followed the sequence: ferrous ion > synthesized iron oxide >> magnetite hematite > goethite. According to these results, the most effective iron oxide catalyst had the structure similar to natural hematite. The surface oxidation state of the catalyst was between magnetite and hematite (+2.5 ~ +3.0). Phenol degraded completely in 40 min at neutral pH (pH = 7). Soluble ferric and ferrous ions were not detected in the filtrate from Fenton reaction solution by AAS. The formation of hydroxyl radicals was confirmed by EPR.

The Effects of Ferrous Ion on Properties of Bright Nickel Electordeposit (광택 니켈 도금속에 미치는 이가식 이온의 영향)

  • 육기진;여운관;박룡진
    • Journal of the Korean institute of surface engineering
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    • v.15 no.4
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    • pp.218-225
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    • 1982
  • The effects of ferrous ion on the properties of bright nickel electrodeposit were exa-mined. Iron exists as ferrous ion (Fe+2) and ferric ion (Fe+3) in the bath, a portion of the former tend to be oxidized to the somewhat harmful ferric ion. Iron was added to bath as the ferrous sulfate, ferrous ion prevented from the oxidation with citric acid. It was found that the hardness was increased as the concentration of ferrous ion, the ductility was slightly increased too. The appearance can obtain the wide bright deposits within 4g/$\ell$. The corrosion resistance drastically dropped from 5g/$\ell$ In the case of considering the effect of ferrous ion on the corrosion resistance and the appearance, the allowable limits is 4g/$\ell$, if the reductant is used.

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Effect of Pine Needle Extract on Fe ion and Active Oxygen Related Lipid Oxidation in Oil Emulsion (Fe ion과 활성산소 관련 지방산화반응에 미치는 솔잎 추출물의 영향)

  • 김수민;조영석
    • Food Science and Preservation
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    • v.6 no.1
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    • pp.115-120
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    • 1999
  • This study was carried out to investigate the effect of Pine needle extract on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The results were summarized as follow; The pine needle extracts didn`t show a distinct effect on reduction of lipid oxidation if the iron ion didn`t exist in oil emulsion. The pine needle extracts played role as a strong chelating agents to bind iron ion if Ferrous iron(Fe\ulcorner) exist in oil emulsion. Ferric iron(Fe) was lower effect than Ferrous iron(Fe) on free radical reaction in oil emulsion. And also, the Fe\ulcorner reacted with pine needle extract did not show distinct effect on free radical reaction, compared to Fe\ulcorner reacted with pine needle extract. And also, Pine needle extracts reacted with H\ulcornerO\ulcorner were tended to show a low oxygen scavenging ability in case of H\ulcornerO\ulcorner only was existed, compared to those of H\ulcornerO\ulcorner + Fe\ulcorner complex. Pine needle extracts were the most powerful Fe\ulcorner binding agents, compared to other strong synthetic antioxidants such as EDTA and DTPA.

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Oxidation of organic contaminants in water by iron-induced oxygen activation: A short review

  • Lee, Changha
    • Environmental Engineering Research
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    • v.20 no.3
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    • pp.205-211
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    • 2015
  • Reduced forms of iron, such as zero-valent ion (ZVI) and ferrous ion (Fe[II]), can activate dissolved oxygen in water into reactive oxidants capable of oxidative water treatment. The corrosion of ZVI (or the oxidation of (Fe[II]) forms a hydrogen peroxide ($H_2O_2$) intermediate and the subsequent Fenton reaction generates reactive oxidants such as hydroxyl radical ($^{\bullet}OH$) and ferryl ion (Fe[IV]). However, the production of reactive oxidants is limited by multiple factors that restrict the electron transfer from iron to oxygen or that lead the reaction of $H_2O_2$ to undesired pathways. Several efforts have been made to enhance the production of reactive oxidants by iron-induced oxygen activation, such as the use of iron-chelating agents, electron-shuttles, and surface modification on ZVI. This article reviews the chemistry of oxygen activation by ZVI and Fe(II) and its application in oxidative degradation of organic contaminants. Also discussed are the issues which require further investigation to better understand the chemistry and develop practical environmental technologies.

Synthesis of Iron Oxide Using Ferrous Sulfate by Ozone Treatment (황산제일철 용액의 오존 처리에 의한 산화철 합성)

  • Kim Sam-Joong;Suhr Dong-Soo;Eom Tae-Hyoung;Song Kyung-Sub;Roh Jea-Seung
    • Korean Journal of Materials Research
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    • v.14 no.5
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    • pp.353-357
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    • 2004
  • The influences of the ozone oxidation, reaction temperature and NaOH equivalent ratio on the iron oxide formation were studied with fixed ferrous sulfate concentration(0.5M $FeSO_4$$7H_2$O). Geothite($\alpha$-FeOOH) and/or Magnetite ($Fe_3$$O_4$) were synthesized depending on the reaction conditions. The characteristics of the synthesized powders were evaluated by XRD, SEM and quantitative phase analysis. The synthetic conditions to get Goethite were quite different from the results of Kiyama's and the Goethite was conveniently synthesized at low temperature and at low NaOH equivalent ratio.

저품위 동광석의 세균침출에 관한 연구 2

  • 이강순;민봉희;장정순
    • Korean Journal of Microbiology
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    • v.10 no.1
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    • pp.1-8
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    • 1972
  • This experiment was carried out to investigate the physiological characteristics of isolated bacteria, Ferrobacillus ferooxidans from copper mine water in Korea. The results obtained were as follows ; 1. The optimum pH range for the growth of these bacteria was 2.0-3.0 and optimum temperature was $20^{\circ}C$-$30^{\circ}C$. 2. The oxidation curves of ferrous iron to the ferric iron ran parallel with the growth curves. 3. The optimum nitrogen concentration was 400-800 ppm and the minimal flow rate of air for the maximal growth of the bactria was 70 ml air/min./200ml medium. 4. The growth of these bacteria was inhibited by the absence of ferrous iron and by the addition of sulfur. 5. Ferrous iron at a concentration of 9000 ppm, appeared to be optimum for the most rapid growth of Ferrobacillus ferrooxidans.

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