• 제목/요약/키워드: Iron(III)

검색결과 323건 처리시간 0.021초

Effects of Iron on Arsenic Speciation and Redox Chemistry in Acid Mine Water

  • Bednar A.J.;Garbarino J.R.;Ranville J.F.;Wildeman T.R.
    • 대한자원환경지질학회:학술대회논문집
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    • 대한자원환경지질학회 2004년도 International Symposium
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    • pp.9-28
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    • 2004
  • Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not 짐ways hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides depletes iron from some systems, and this also affects arsenite and arsenate concentrations differently through sorption processes.

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FeO/Fe(II) 시스템에서 TCE의 제거 특성 (Characteristics of the TCE removal in FeO/Fe(II) System)

  • 성동준;이윤모;최원호;박주양
    • 대한토목학회논문집
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    • 제28권1B호
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    • pp.149-152
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    • 2008
  • 철의 환원 특성에 관한 연구는 이미 널리 수행되었으며 특히 미네랄과 2가철의 반응 메커니즘은 2가철의 흡착이나 바운드를 통해 Fe(II)-Fe(III) (hydr)oxides를 생성하여 2가철이 3가철로 산화됨으로써 물질을 환원시키는 것으로 받아들여지고 있다. 그러나 2가철로 개질된 재강슬래그를 이용한 DS/S 실험과정에서 이러한 메커니즘으로 설명하기 힘든 현상을 발견하였다. 재강슬래그의 주요 성분중의 하나인 FeO와 Fe(II)만을 이용하여 TCE의 분해과정을 실험해 본 결과 초기 TCE의 분해가 이루어지지 않다가 급속히 분해되는 현상을 보였으며 이러한 시스템에서 TCE의 분해는 예상치 못한 결과였다. FeO/Fe(II) 시스템은 3가철이 존재하지 않기 때문에 기존의 Fe(II)-Fe(III) (hydr)oxides를 형성하는 환원 메커니즘으로는 설명할 수 없었다. 따라서 본 연구에서는 TCE의 분해실험과 분해 부산물의 측정, 2가철과 3가철을 확인함으로써 FeO/Fe(II) 시스템의 환원특성을 확인해 보고자 하였다. 실험 결과 2가철이 FeO에 흡착 또는 바운드 되는 것을 확인 할 수 는 있었으나 기존의 메커니즘으로 설명하기에는 부족한 부분이 있었다. 분해부산물들을 통해 환원으로 인한 TCE의 분해는 의심의 여지가 없었으나 FeO/Fe(II) 시스템이 새로운 species를 형성하는지, 혹은 FeO에 Fe(II)가 흡착 또는 바운드 되어 이제껏 알려지지 않은 형태의 새로운 미네랄 상을 형성하는지는 좀 더 상세한 연구가 필요하다.

동보(東寶) 중석(重石)-모리브덴 광상(鑛床)의 광물공생(鑛物共生)과 유체포유물(流體包有物) (Mineral Paragenesis and Fluid Inclusions of the Dongbo Tungsten-Molybdenum Deposits)

  • 박희인;문상호;배영부
    • 자원환경지질
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    • 제18권4호
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    • pp.331-342
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    • 1985
  • The Dongbo tungsten-molybdenum deposits are fissure-filling veins emplaced in granites of late Cretaceous age. Integrated field, mineralogic and fluid inclusion studies were undertaken to illuminate the characters and origin of the ore deposits. Mineral paragenesis is complicated by repeated fracturing, but four distinct depositional stages can be recognized; (I) tungsten-molybdenum minerals-quartz-chlorite stage, (II) iron-oxide and sulfides-quartz stage, (III) iron -oxide-base metal sulfides-sulfosalts-quartz-carbonates stage, (IV) barren rhodochrosite-zeolite stage. Fluid inclusion studies were carried out for stage I quartz and stage III quartz, sphalerite and calcite. Fluid inclusion studies reveals highly systematic trends of homogenization temperature and salinity throughout the mineralization. Ore fluids during stage I were complex, NaCl rich brine and salinity reached values as high as 34.4 weight percent equivalent NaCl, but the later ore fluids were more dilute and reached to 9.7 weight percent equivalent NaCl during stage III. Intermittent boiling of ore fluid during stage I is indicated by the fluid inclusions in stage I quartz. Depositional temperatures and pressures during stage I range from $520^{\circ}C$ to $265^{\circ}C$and from 600 to 400 bars. Homogenization temperatures of the stage III quartz, sphalerite and calcite range from $305^{\circ}C$ to $190^{\circ}C$. Fluid inclusion data from the Dongbo mine are nearly similar to those from other hydrothermal tungsten deposits in the Kyeongsang basin. Depositional temperature and salinity of ore fluids during precipitation of tungsten-molybdenum minerals in Dongbo mine were much higher, but $CO_2$ contents were much lower than those from hydrothermal tungsten-molybdenum deposits of late Cretaceous plutonic association in central parts of Korean peninsula.

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신성빈혈(腎性貧血)에 관(關)한 연구(硏究) - 만성신질환(慢性腎疾患)의 철대사(鐵代謝) 및 적혈구수명(赤血球壽命)에 관(關)하여 - (Study on Renal Anemia - A Double Tracer Study on Iron Metabolism and Red Cell Life Span in Chronic Renal Diseases using Radioactive Iron ($^{59}Fe$) and Chromium($^{51}Cr$) -)

  • 정경태;이문호
    • 대한핵의학회지
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    • 제2권1호
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    • pp.27-41
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    • 1968
  • The ferrokinetics and red cell life spans of the patients with chronic glomerulonephritis were investigated by the double tracing method using radioactive iron ($^{59}Fe$) and chromium ($^{51}Cr$). According to the serum NPN levels, the patients were subdivided into 3 groups: Group 1. 6 patients, had the levels below 40 mg/dl Group 2. 6 patients, had the levels between 41 mg/dl to 80 mg/dl Group 3. 10 patients, had the levels above 80 mg/dl The results were as follows: 1) Red blood cell-, hematocrit- and hemoglobin values were moderately reduced in patients with normal serum NPN levels, while markedly reduced in patients with elevated serum NPN levels. 2) The plasma volume was increased, while the red cell volume was decreased in patients with elevated serum NPN levels, hence, total blood volume was unchanged. 3) The serum iron level was slightly reduced h patients of groups 1 and 2, while was within the normal ranges in patients of group 3. 4) i) In patients with normal serum NPN levels, the plasma iron disappearance rate, red cell iron utilization rate, red cell iron turnover rate, daily red cell iron renewal rate, circulating red cell iron and red cell iron concentration were within the normal ranges, while the plasma iron turnover rate was slightly reduced. ii) In patients with elevated serum NPN levels, the plasma iron disappearance rate was delayed, while the plasma iron turnover rate was within the normal ranges. The red cell iron utilization rate, red cell iron turnover rate and circulating red cell iron were decreased and the period in which the red cell iron utilization rate reachd its peak was delayed in Group 3 patients. The daily red cell iron renewal rate and the red cell iron concentration were unchanged. iii) The mean red cell life span was within the normal ranges in patients with normal serum NPN levels, while was shortened in patients with elevated serum NPN levels.

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Removal of TCE using zero valent iron (ZVI) with other contaminants

  • 조현희;박재우
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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    • pp.58-61
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    • 2002
  • An alternative to pump and treat groundwater remediation is the use of reactive barriers. Zero valent iron (ZVI) is particularly useful as a reductant of chlorinated hydrocarbons because of its low cost and lack of toxicity ZVI can drive the dechlorination of chlorinated organic compounds and the reduction of chromium from the Cr(Ⅵ) to the Cr(III) state. The contaminants in subsurface environment usually exist as the mixed compounds. Therefore, the objective of this research is to study the effect of the other compounds on TCE removal by ZVI. The removal mechanism of TCE by ZVI is separated the dechlorination and sorption. TCE removal by ZVI slightly increased in presence of naphthalene as the non-reduced compound. TCE removal by ZVI remarkable decreased in presence of carbon tetrachloride, nitrate, and chromate as the reduced compounds. This research suggests that the effect of the coexisted compounds on the removal chlorinated compounds by reactive barrier technology should be considered for practical application.

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디젤과 등유로 오염된 토양의 철광석으로 촉매화된 과수를 이용한 처리에 관한 연구 (A Study on Treatment of Soils Contaminated by Diesel and Kerosene Using Hydrogen Peroxide Catalyzed by Naturally Occurring Iron Minerals)

  • 최진호;김상대;문세기;공성호
    • 공업화학
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    • 제10권1호
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    • pp.24-29
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    • 1999
  • 천연 토양 속에 많이 존재하는 철광석인 goethite, magnetite와 과산화수소수를 이용해 펜톤 유사 반응(Fenton-like oxidation)을 유도하여 디젤과 등유가 같은 중량 비율로 오염된 silica sand를 회분식 시스템으로 처리하여 보았다. 과산화수소수의 pH(3, 7) 농도(0%, 1%, 7%, 15%, 35%), 초기 오염물의 농도(0.2, 0.5, 1.0 g-오염물/kg-모래), 그리고 철광석(iron minerals)의 양(0, 1, 5 wt % magnetite 또는 goethite)을 달리하여 반응조건들을 조사하였다. Silica sand-철광석-$H_2O_2$ system에서의 오염물의 분해는 잔존 Total Petroleum Hydrocarbon(TPH)의 농도를 분석하여 확인하였다. 최적 실험 pH는 3이었고, 철광석이 철공급원으로 사용된 경우가 $FeSO_4$ 용액이 철공급원으로 사용된 경우보다 과수의 소모가 적어서 더 효율적이었다. 초기 오염물의 농도 1.0 g-오염물/kg-모래(5 wt % magnetite)에 과산화수소수의 농도를 0%, 1%, 7%, 15%, 그리고 35%로 달리하여 본 결과 8일후 각각 0%, 24.5%, 44%, 50%, 그리고 70%의 TPH 감소를 보였다. 같은 오염물 농도하에서 15%의 과산화수소를 사용하고, 철광석의 양이 0, 1, 5, 10 wt %로 변화되었을 경우, 오염물의 제거량은 magnetite의 사용시 각각 0%, 33.5%, 50%, 60%, goethite의 사용시는 각각 0%, 29%, 41%, 53%이었다. Magnetite system은 iron(II)과 iron(III)이 공존하며, 미량의 철성분이 용해되므로 goethite system보다 오염물의 분해가 더 많이 일어나는 것으로 보인다. 그러나 용해된 철성분은 철광석 표면에 침전물의 형태로 쌓이게 되어 철광석 표면의 전자교환능력을 감소시키고 과산화수소수를 quenching시키는 것으로 사려된다. 그리하여 goethite system에서 과산화수소수가 적게 소모되어 magnetite system보다 나은 처리효율을 가지는 것으로 나타났다. 토양을 shaker를 이용하여 혼합시킨 결과 오염물의 제거량이 magnetite의 경우 41%, goethite의 경우 30%만큼 증가하였다. 이 연구의 결과를 통하여 볼 때 천연토양속에는 magnetite와 goethite같은 철광석이 함유되어 있으므로 별도의 철성분 첨가없이 과산화수소수의 처리만으로도 석유로 오염된 토양의 in-situ 또는 ex-situ한 처리가 가능할 것으로 보인다.

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Comparison of Anodic Community in Microbial Fuel Cells with Iron Oxide-Reducing Community

  • Yokoyama, Hiroshi;Ishida, Mitsuyoshi;Yamashita, Takahiro
    • Journal of Microbiology and Biotechnology
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    • 제26권4호
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    • pp.757-762
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    • 2016
  • The group of Fe(III) oxide-reducing bacteria includes exoelectrogenic bacteria, and they possess similar properties of transferring electrons to extracellular insoluble-electron acceptors. The exoelectrogenic bacteria can use the anode in microbial fuel cells (MFCs) as the terminal electron acceptor in anaerobic acetate oxidation. In the present study, the anodic community was compared with the community using Fe(III) oxide (ferrihydrite) as the electron acceptor coupled with acetate oxidation. To precisely analyze the structures, the community was established by enrichment cultures using the same inoculum used for the MFCs. High-throughput sequencing of the 16S rRNA gene revealed considerable differences between the structure of the anodic communities and that of the Fe(III) oxide-reducing community. Geobacter species were predominantly detected (>46%) in the anodic communities. In contrast, Pseudomonas (70%) and Desulfosporosinus (16%) were predominant in the Fe(III) oxide-reducing community. These results demonstrated that Geobacter species are the most specialized among Fe(III)-reducing bacteria for electron transfer to the anode in MFCs. In addition, the present study indicates the presence of a novel lineage of bacteria in the genus Pseudomonas that highly prefers ferrihydrite as the terminal electron acceptor in acetate oxidation.

Salmonella Typhimurium SL1344의 사람의 트렌스페린(hTf)에 부착된 철 이용에 관한 연구 (Salmonella Typhimurium SL1344 Utilizing Human Transferrin-bound Iron as an Iron Source Regardless of Siderophore-mediated Uptake)

  • 최윤정;유아영;김삼웅;황지환;강호영
    • 생명과학회지
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    • 제27권1호
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    • pp.72-77
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    • 2017
  • S. Typhimurium SL1344는 성장을 위한 보조인자로 무기철이 요구된다. 철 킬레이트제인 ethylenediamine di-o-hydroxyphenylactic acid (EDDA)가 첨가 된 M9 최소배지에서 S. Typhimurium은 성장에 있어 철 이용이 완전하게 억제된다. 하지만, 세균이나 곰팡이와 같은 미생물들은 철이 부족한 환경에서 제한된 철을 이용하기 위해 사이드로포어를 생산한다. 사람에서 유래한 트랜스페린(hTf)-철 복합체를 M9 배지에 첨가한 조건에서 S. Typhimurium의 사이드로포어 생산은 완전하게 중단되었다. 반면, S. Typhimurium의 성장은 염화철($FeCl_3$)을 첨가한 조건과 동일한 수준으로 유지되었다. 이 결과는 사이드로포어의 생산 없이도 S. Typhimurium이 hTf에 부착된 철을 직접적으로 이용할 수 있다는 것을 알 수 있다. 돌연변이주의 구축과 이를 이용한 분석을 통하여 우리는 세균이 hTf-철 복합체를 직접적으로 이용할 수 있다는 것을 확인할 수 있었다.

염화철(III)로 표면개질 활성탄을 이용한 비소제거 (Arsenic Removal using the Surface Modified Granular Activated Carbon treated with Ferric Chloride)

  • 박유리;홍성혁;김정환;박주양
    • 상하수도학회지
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    • 제26권1호
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    • pp.77-85
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    • 2012
  • The present study investigates treatment methods for removal of arsenic from wastewater. The granular activated carbon (GAC) with the coating of iron chloride ($FeCl_3$) was used for the treatment of a low concentration of arsenic from wastewater. Batch experiments were performed to investigate the synthesis of Fe-GAC (Iron coated granular activated carbon), effects of pH, adsorption kinetics and the Langmuir model. The synthesized Fe-GAC with 0.1 M $FeCl_3$ shows best removal efficiency. Adsorption studies were carried out in the optimum pH range of 4-6 for arsenic removal. The Fe-GAC showed promising results by removing 99.4% of arsenic. In the adsorption isotherm studies, the observed data fitted well with the Langmuir models. In continuous column study showed that As(V) could be removed to below 0.25 mg/L within 1,020 pore volume. Our results suggest that the surface modified granular activated carbon treated with $FeCl_3$ for effective removal of arsenic from wastewater.

근육조성에 따른 축종특이성 구명 III. 축종별 근육중 무기물 함량 (Species characterization of animal by muscle composition analysis III. The contents of minerals in muscle from various species)

  • 이명헌;김상근
    • 대한수의학회지
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    • 제39권3호
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    • pp.501-512
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    • 1999
  • We analyzed the contents of 12 types of minerals such as calcium in muscle from various species. Thereafter we observed changes of the concentrations according to age, part and sex in major domestic animals. The concentrations of calcium, iron, sodium, potassium, magnesium and zinc were high respectively whilst the content of cobalt, chromium, copper, manganese, molybdenum and nickel were low respectively in the muscle. The concentration of calcium was high in duck and dog but low in pig and horse. Also high level of sodium content was detected in dog and the content of potassium, iron showed high level in horse compared with the content in other animals. In 6 types of microminerals as cobalt, the level of muscle were no more than 1 ppm showing very low content in all animal, but $2.99{\pm}0.85$ppm of copper in duck was an exceptional case. According to the age some species showed small range of variation centering on macrominerals and there was no remarkable change in microminerals. Distribution of minerals was different according to the part and the variation was very diverse compared with other factors such as age and sex. Additionally, the content of minerals in muscle was higher in female than in male chicken and duck. In conclusion, the difference of the content of minerals according to the species was mainly focused on macrominerals.

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