• 제목/요약/키워드: hydrous ferric oxide

검색결과 8건 처리시간 0.02초

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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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%.

Synthesis and Characterization of Adsorbent for Pb(II)-capture by using Glow Discharge Electrolysis Plasma

  • Gao, Jinzhang;Wang, Youdi;Yang, Wu;Li, Yan
    • Bulletin of the Korean Chemical Society
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    • 제31권2호
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    • pp.406-414
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    • 2010
  • A novel polyacrylamide grafted hydrous ferric oxide adsorbent composite has been synthesized by using glow discharge electrolysis plasma. To optimize the synthesis conditions, the following parameters were examined in detail: applied power, discharge time, post polymerization temperature, post polymerization time, amount of crosslinking agent and hydrous ferric oxide gel added and so on. The adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The removal percentage of the adsorbent in Pb(II) solution was examined and the data obtained showed that the adsorbent composite has a high capacity for lead ion. For the use in wastewater treatment, the thermodynamic and kinetic of Pb(II)-capture were also studied. Results indicated that the adsorption reaction was a spontaneous and an endothermic process, and it seems to be obeyed a pseudo-secondorder rate model. Moreover, the adsorption isotherm of Pb(II)-capture is following the Langmuir and Freundlich isotherm models.

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%.

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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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.