• 제목/요약/키워드: Iron hydrous oxide

검색결과 9건 처리시간 0.021초

운모표면에 대한 $\alpha$산화철 흡착 (Adsorption of $\alpha$-Fe2O3 on the Surface of Mica Particles)

  • 김대웅;조동희;김명숙;박면용
    • 한국세라믹학회지
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    • 제24권3호
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    • pp.215-222
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    • 1987
  • ${\alpha}$-Ferric Hydrous Oxide and ${\alpha}$-Ferric Oxide were obtained as following processes that Ferric Nitrate solution was adjusted to pH 6-8 with Ammonium Hydroxide, refluxed the Iron precipitate for 1 hr. at 80$^{\circ}C$, washed it with water and Methanol (95%), dried it to obtain ${\alpha}$-Ferric Hydrous Oxide at 60$^{\circ}C$, and then heated in atmosphere to prepare ${\alpha}$-Ferric Oxide for 1 hr. at 450$^{\circ}C$. Mica particles cleaned with ultrasonicator (45KHz) in water were mixed with Ferric Nitrate solution and treated it to adsorb ${\alpha}$-Ferric Oxide on the surface of mica particles by using the abovementioned processes, but the heated temperature was at 500$^{\circ}C$. The maximum wavelength of reflected light on the surface of mica-${\alpha}$-Ferric Oxide (50%) was appeared at 546nm but -Ferric Oxide free mica only was at 436 nm. The maximum wavelength was shifted to longer when the weight ratios of ${\alpha}$-Ferric Oxide to mica was changed from 1% to 50%.

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Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

  • Sinha, Shahnawaz;Amy, Gary;Yoon, Yeo-Min;Her, Nam-Guk
    • Environmental Engineering Research
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    • 제16권3호
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    • pp.165-173
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    • 2011
  • The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated microsand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of $C_{eq}=10\;{\mu}g/L$ were 500 mg/L for AA and GFH, 520-1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60-95%.

Evaluation of dynamic behavior of coagulation-flocculation using hydrous ferric oxide for removal of radioactive nuclides in wastewater

  • Kim, Kwang-Wook;Shon, Woo-Jung;Oh, Maeng-Kyo;Yang, Dasom;Foster, Richard I.;Lee, Keun-Young
    • Nuclear Engineering and Technology
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    • 제51권3호
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    • pp.738-745
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    • 2019
  • Coprecipitation using hydrous ferric oxide (HFO) has been effectively used for the removal of radionuclides from radioactive wastewater. This work studied the dynamic behavior of HFO floc formation during the neutralization of acidic ferric iron in the presence of several radionuclides by using a photometric dispersion analyzer (PDA). Then the coagulation-flocculation system using HFO-anionic poly acrylamide (PAM) composite floc system was evaluated and compared in seawater and distilled water to find the effective condition to remove the target nuclides (Co-60, Mn-54, Sb-125, and Ru-106) present in wastewater generated in the severe accident of nuclear power plant like Fukushima Daiichi case. A ferric iron dosage of 10 ppm for the formation of HFO was suitable in terms of fast formation of HFO flocs without induction time, and maximum total removal yield of radioactivity from the wastewater. The settling time of HFO flocs was reduced by changing them to HFO-PAM composite floc. The optimal dosage of anionic PAM for HFO-anionic PAM floc system was approximately 1-10 ppm. The total removal yield of Mn-54, Co-60, Sb-125, Ru-106 radionuclides by the HFO-anionic PAM coagulation-flocculation system was higher in distilled water than in seawater and was more than 99%.

黃酸第一鐵로부터 含水酸化鐵生成에 關한 硏究 (A Study on the Formation of Hydrous Ferric Oxide from Ferrous Sulfate)

  • 성주경;설수덕;황용길
    • 대한화학회지
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    • 제19권2호
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    • pp.142-146
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    • 1975
  • 황산제일철을 원료로 해서 함수산화철 안료를 제조하기 위한 실험이다. 황산제일철을 암모니아로 중화해서 Mohr's salt(ferrous ammonium sulfate)을 만들고 Mohr's salt의 농도를 Fe(II) 이온농도, 14${\sim}$72g/l, 수소이온농도를 pH3 또는 6으로 조절한뒤, 반응온도는 $90{\sim}100^{\circ}C$로 일정하게 유지하고 반응시간 2시간, 3기압으로 공기 가압한 결과는 다음과 같다. Mohr's salt의 농도가 진하고, 중성으로 갈수록 함수산화철의 수득율이 증가되며, Mohr's salt 농도가 Fe(II) 이온농도, 42.81g/l 일때, 91.5% 이상의 수득율을 얻었다. 이렇게하여 생성된 함수산화철의 결정형은 $\alpha$-goethite형이며, 색상도 천연 ${\alpha}$-goethite와 유사하였다. 이것을 $500^{\circ}C$로 하소(calcination)하니 미려한 적갈색을 띤 ${\alpha}-Fe_2O_3$가 생성되었다.

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합성(合成) 수산화(水酸化) 철(鐵) 광물(鑛物)과 수산화(水酸化) 알루미늄 광물(鑛物)의 표면(表面) 전하(電荷) 및 물리화학적(物理化學的) 특성(特性)에 관(關)한 연구(硏究) (Studies on the Surface Charge Characteristics and Some Physico-Chemical Properties of two Synthetic Iron Hydrous Oxides and one Aluminum Hydroxide Minerals)

  • 임수길
    • 한국토양비료학회지
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    • 제17권2호
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    • pp.147-154
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    • 1984
  • 수산화철 및 알루미늄 광물을 함유하는 토양의 물리화학적 및 표면 전하의 특성을 보다 정확히 이해하기 위하여 $FeCl_3$$AlCl_3$ 용액으로부터 두 종류의 수산화철광물(A와 B) 및 수산화알루미늄 광물을 합성하였다. X-ray 회절분석에 의하여 수산화철 A광물은 무정형, B광물은 다량의 무정형과 함께 goethite광물이 존재하는 것으로 밝혀졌다. $105^{\circ}C$에서 건조한 결과 A광물은 소량의 무정형과 함께 akaganeite 광물, B광물은 순수 goethite로 변하였다. 한편 합성된 수산화알루미늄 광물은 gibbsite와 bayerite 광물이 약 7:3의 비율로 혼합된 것으로 밝혀졌다. 유리 또는 무정형의 철과 알루미늄을 선택적으로 용출하는 것으로 알려진 dithionite와 oxalate용액을 이용하여 이들 수산화물을 세척한 결과 dithionite가 철 용출력은 가장 강했으나 oxalate에 의한 알루미늄 용출만이 수산화알루미늄 광물중의 무정형 광물 함량을 감소하고 결정성 광물의 결정도를 높였다. 타 광물과 달리 수산화철 A광물에서 dithioite에 의한 철의 용출이 가장 많았으나 냉동건조를 제외한 건조($105^{\circ}C$의 열건조 및 $P_2O_5$ 건조)에 의하며 그 용출량이 급격히 감소하였다. 수산화철 A광물의 표면적이 가장 컸으며 역시 냉동 건조를 제외한 건조처리에 의하여 그 표면적이 현저히 감소하였고, 이들 광물중의 점토($2{\mu}m$이하)함량도 표면적의 변하와 같은 경향을 보였다. 또한 표면 전하의 절대량 발달도 수산화철 A광물이 가장 컸으며 이들 광물들의 등전점은 각각 수산화철 A광물이 8.0-8.5사이, B광물이 7.5-8.0사이로써 높았고 수산화알루미늄 광물이 5.5-6.0 사이로써 낮았다.

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Direct and Indirect Reduction of Cr(VI) by Fermentative Fe(III)-Reducing Cellulomonas sp. Strain Cellu-2a

  • Khanal, Anamika;Hur, Hor-Gil;Fredrickson, James K.;Lee, Ji-Hoon
    • Journal of Microbiology and Biotechnology
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    • 제31권11호
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    • pp.1519-1525
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    • 2021
  • Hexavalent chromium (Cr(VI)) is recognized to be carcinogenic and toxic and registered as a contaminant in many drinking water regulations. It occurs naturally and is also produced by industrial processes. The reduction of Cr(VI) to Cr(III) has been a central topic for chromium remediation since Cr(III) is less toxic and less mobile. In this study, fermentative Fe(III)-reducing bacterial strains (Cellu-2a, Cellu-5a, and Cellu-5b) were isolated from a groundwater sample and were phylogenetically related to species of Cellulomonas by 16S rRNA gene analysis. One selected strain, Cellu-2a showed its capacity of reduction of both soluble iron (ferric citrate) and solid iron (hydrous ferric oxide, HFO), as well as aqueous Cr(VI). The strain Cellu-2a was able to reduce 15 μM Cr(VI) directly with glucose or sucrose as a sole carbon source under the anaerobic condition and indirectly with one of the substrates and HFO in the same incubations. The heterogeneous reduction of Cr(VI) by the surface-associated reduced iron from HFO by Cellu-2a likely assisted the Cr(VI) reduction. Fermentative features such as large-scale cell growth may impose advantages on the application of bacterial Cr(VI) reduction over anaerobic respiratory reduction.

폐광산 인근 논토양과 수도의 비소함량 조사 (Concentration of Arsenic in Rice Plants and Paddy Soils in the Vicinity of Abandoned Zinc Mine)

  • 김찬용;박만;이동훈;최충렬;김광섭;최정;서영진
    • Applied Biological Chemistry
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    • 제45권3호
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    • pp.152-156
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    • 2002
  • 토양중 비소함량이 식물체내 이동에 미치는 영향을 조사하기 위하여 아연 폐광산 근처 논토양과 벼에 함유된 비소함량을 조사하였다. 논토양 중 비소는 total As의 약 52.9%, extractable As의 74%정도가 iron oxide phase에 bound된 비소(Fe-As)였으며 수용성 비소(Ws-As)는 대부분 검출한계 이하였다. 비소의 연속추출 결과, extractable As fraction중 Fe-As가 1 N-HCI 가용성 As와 가장 높은 상관을 나타내었고, 이것은 토양중 Fe-As 의 함량이 많기 때문으로 생각된다. 식물체 부위별 비소의 농도는 뿌리>잎 줄기>곡실순이었으며 곡실 중에 함유된 비소농도는 FDA 식품기준 1.08mg/kg 이하였다. 토양중 As fraction과 식물체 부위별 As함량간의 상관관계를 분석한 결과 Al-As fraction이 뿌리와 0.821, 줄기 0.888, 잎 0.777로 비교적 높은 상관계수를 나타내었고, 작물에 가장 잘 이용될 수 있는 비소의 형태는 Al-As fraction인 것으로 판단된다.