• Title/Summary/Keyword: ferrous iron

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Reductive Dechlorination of Tetrachloroethylene in Soils by Fe(II)-Based Degradative Solidification/Stabilization

  • Hwang, Inseong;Batchelor, Bill
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.49-52
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    • 2001
  • An experimental study was conducted to test the feasibility of degradative solidification/stabilization (DS/S) process in treating tetrachloroethylene (PCE) in solid phase systems. The Fe(II)-based ds/s process successfully treated PCE in a soil at the reaction rates that would not allow significant release of the contaminant in the environment. A leach model was also developed that could describe the relative importance of leaching and degradation in ds/s. The first and second Damkohler numbers and dimensionless time were important parameters that determined leaching precesses in wastes treated by ds/s.

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Effects of Cervus elaphus for herb-acupuncture solution on Antioxidation in Rat‘s liver (흰쥐의 간(肝) 조직(組織)에서 녹용(鹿茸) 약침(藥針) 제제(製劑)의 항산화작용(抗酸化作用)에 관(關)한 연구(硏究))

  • Yoon, Cheol-Ho;Jeong, Ji-Cheon;Shin, Uk-Seob
    • The Journal of Korean Medicine
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    • v.17 no.2 s.32
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    • pp.191-202
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    • 1996
  • Cervus elaphus for herb-acupuncture solution(CEHAS) was tested for the effects of free radical generating enzyme and lipid peroxidation in rat's liver. In vitro, levels of lipid peroxide in tissues of liver were proportionally decreased to concentration of CEHAS. They were much more decreased. when lipid peroxidation was induced with ferrous iron $(Fe^{-2})$. Also, enzyme activities of xanthine oxidase were decreased. The ratio of type conversion of xanthine oxidase was lowered, too. But, here was not special changes on enzyme activities of aldehyde oxidase. These results suggest that CEHAS decrease the activities of free radical generating enzymes such as xanthine oxidase which form lipid peroxide.

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Role of heme oxygenase-1 expression by dietary phytoconstituents: A nutritional cytoprotective strategy for human diseases

  • Lee, Seung Eun;Park, Yong Seek
    • CELLMED
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    • v.3 no.1
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    • pp.1.1-1.7
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    • 2013
  • The present review investigates the role of the cytoprotective enzyme heme oxygenase-1 (HO-1) in human diseases and explores strategies for its clinical use. In recent years, there has been a growing evidence, for the beneficial effects of some phytoconstituents via induction of HO-1 expression, contained in commonly used spices, fruits, and herbs, in preventing various pathologic conditions, including cancer, diabetes, and cardiovascular diseases. HO-1 catalyzes the rate-limiting step in heme catabolism to generate ferrous iron, carbon monoxide, and biliverdin. HO-1 is reported to play crucial roles in cellular protection, such as anti-inflammatory, anti-proliferative and anti-apoptotic effects. These evidences indicate that HO-1 may functions as a potential therapeutic target in various human diseases. The article highlights the current status of the development of the HO-1 modulation pathway using dietary phytoconstituents.

Effects of Cervus elaphus for herb-acupuncture solution on Antioxidation in Rat's kidney (녹용(鹿茸) 약침(藥針) 제제(製劑)가 흰쥐 신장(腎臟) 조직(組織)의 항산화(抗酸化) 작용(作用)에 미치는 영향(影響))

  • Yoon, Cheol-Ho;Jeong, Ji-Cheon;Shin, Uk-Seob
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.192-204
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    • 1996
  • Cervus elaphus for herb-acupuncture solution (CEHAS) was tested for the effects of free radical generating enzyme and lipid peroxidation in rat's kidney. In vitro, levels of lipid peroxide in tissues of kidney were proportionally decreased to concentration of extracts prepared from CEHAS. They were much more decreased, when lipid peroxidation was induced with ferrous iron (FeII). Also, enzyme activities of xinthine oxidase were decreased. The ratio of type conversion of xanthine oxidase was lowered, two. But, it was not seen changes on enzyme activities of aldehyde oxidase. These results suggest that CEHAS decrease the activities of free radical generating enzymes such as xanthine oxidase which form lipid peroxide.

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Treatment of High Strength para-Nitrophenol using Fenton-like Oxidation Catalyzed by Steeler's Dust (제강분진을 촉매로 활용한 펜톤유사산화에 의한 고농도 para-Nitrophenol의 처리)

  • 배범한;정재훈;이성재;장윤영;박규홍;장윤석
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.136-139
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    • 2000
  • Fenton-like oxidation of para-nitrophenol(PNP) was studied using hydrogen peroxide iii combination with steeler's dust substituted for ferrous iron in Fenton's reaction. Various factors critical in the degradation of PNP were studied, including hydrogen peroxide dosage, concentration of steeler's dust. and initial pH. Experimental results showed that 1,000mg/L PNP and its oxidation intermediate could be mostly decomposed within 30m1n by 10g/L steeler's dust, 0.25% hydrogen peroxide, and initila pH of 3.0. The reaction rate constant (k) of CODcr concentration were calculated with the addition of steeler's dust(0.0059 min$^{-1}$ (g/L)$^{-1}$ ) and hydrogen peroxide(0.2965 min$^{-1}$ (%)$^{-1}$ ), respectively.

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펜톤유사산화반응을 이용한 4-Chlorophenol 분해과정 예측

  • Lee, Ung;Lee, Seong-Jae;Park, Gyu-Hong;Bae, Beom-Han
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.145-148
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    • 2003
  • The batch experiments showed that 0.515mM 4-chlorophenol and its oxidation intermediates could be totally decomposed within 60 minutes by 1g/L steelers' dust and 0.485mM hydrogen peroxide at pH 2.7. The rate constants in the simplified kinetic model proposed in this study were estimated by fitting to the experimental data obtained in $H_2O$$_2$/steelers' dust system. Using the estimated kinetic rate constants, the simulation of 4-chlorophenol, ferrous iron, hydrogen peroxide, and hydroxyl radical concentration was performed. The predicted concentrations of 4-chlorophenol and hydrogen peroxide corresponded to the actual concentrations.

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Niobian Sphene from the McDonald Pegmatite Mine, Bancroft, Ontarion, Canada: Consideration of Substitutions (카나다 온타리오 밴크로프트의 맥도날도 페그마타이트 광산에서 산출된 Nb Sphene: 원소 치환에 관한 고찰)

  • ;Donald R. Peacor
    • Journal of the Mineralogical Society of Korea
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    • v.2 no.1
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    • pp.8-10
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    • 1989
  • Sphene from the McDonald pegmatite near Bancroft, Ontario, Canada was analyzed using EPMA. It contains 4.3 to 6.3 weight percent of Nb2O5 with an average formula Ca1.02(Ti0.62Al0.22Nb0.07Fe0.06Ta0.01)Si0.99(O4.85F0.16). Three types of subtitutions are possible; 1)2Ti4+=(Nb, Ta)5+ + (Al, Fe3+), 2) Ti + O = (Al, Fe3+) + (F, OH), and 3) 2Ti + O = Fe2+ + (Nb, Ta)5+ + (F, OH). T재 different schemes of substitutions for balancing the analysis are considered when the iron is either all ferric or all ferrous. Assuming stoichiometry fo Ca and Si, a general formula derived from the two different schemes is Ca(Ti0.64Al0.22Fe3+0.06-X {{{{Fe_{x}^{2+} }} Nb0.01)Sio4.80-XF0.16(OH)0.04+x.

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EFFECTS OF REACTION TIME AND pH ON FENTON'S BATCH PROCESS FOR THE TREATMENT OF LEACHATE

  • Choi, Heung-Jin;Kim, Il-Kyu
    • Journal of Korean Society on Water Environment
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    • v.18 no.2
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    • pp.169-187
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    • 2002
  • The effects of important parameters such as reaction time and pH on the Fenton's process were evaluated using a batch reactor. It was proven that organic materials and heavy metals in leachate could be successfully removed by Fenton's reagent. Favorable operation conditions were investigated. It was observed that the reaction between ferrous iron and hydrogen peroxide with the production of hydroxyl radical was almost complete in 10 minutes. That is, the oxidation of organic materials by Fenton's reagent was so fast that it was complete in 30 minutes with batch experiments. With the formation of carbonic acid, pH of the batch reactor decreased to favorable acidic conditions without acid addition. The oxidation of organic materials in the leachate showed a pH dependence and was most efficient in the pH range of 2-3.

Selective Oxidation of Cyclohexane at Low Temperature by Fe-Pd Bicatalytic Systems: $FeCl_2$-Pd/alumina System and Pd/$Fe_2O_3$ System

  • 전기원;Lingaiah Nakka;김상범;이규완
    • Bulletin of the Korean Chemical Society
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    • v.18 no.12
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    • pp.1269-1273
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    • 1997
  • The system which employs iron, palladium, molecular oxygen and hydrogen as a model mono-oxygenase, has been investigated to develop a new method for selective cyclohexane oxidation uner mild conditions. This system provides much higher yield and selectivity for the formation of cyclohexanol and cyclohexanone compared to that of the existing industrial method. When the catalytic system, FeCl2-Pd/alumina, was employed, the oxidation system required acetone as a solvent to be efficient and acidifying the solvent by a little addition of acetic acid or HCl made the system more efficient. The Pd catalyst was recyclable without a significant deactivation but the recycling of ferrous chloride showed the decrease in the activity. On the other hand, the heterogeneous catalytic system, Pd/Fe2O3 could be recovered easily and reused after drying treatment.

Chemical Interaction of L-Ascorbic Acid with Ferritin Molecule (가시부영역의 흡수 스펙트럼 변화에 의한 L-Ascorbic Acid와 Ferritin과의 상호작용)

  • 김미옥;나재철;장상문
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.3
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    • pp.542-548
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    • 2004
  • This study consisted of designing a sensitive assay to measure the rate of L-ascorbic acid (AsA)-prompted release of ferritin iron, the use of ferrozine as a chelating agent to trap releases Fe(II). The initial rate of iron release was measured in the appearance of Fe(ferrozine)$_3$$^{2+}$ at 562 nm. The release of iron from ferritin by AsA was dependent on time and AsA conditions under aerobic and anaerobic conditions. Effect of oxygen on the release of iron from ferritin was also confirmed. It was suggested that the release of iron from ferritin was participate not only AsA but also $O_2$$^{[-10]}$ . In this study, it was found that iron can be released from ferritin and chelate as Fe(ferrozine)$_3$$^{2+}$ and the release was more than 50% in the presence of AsA without $O_2$$^{[-10]}$ . Based on the findings, the following can be assumed (1) AsA is diffused into ferritin (2) ferric ion is reduced to ferrous ion (3) is diffused from ferritin.tin.