• Membrane and Water Treatment
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• 제9권6호
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• pp.473-480
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• 2018

The effect of three iron-based adsorbents pre-depositing on ultrafiltration membrane for humic acid (HA) removal and membrane fouling was investigated. The result showed that pre-depositing adsorbents on membrane could not only reduce membrane fouling but also enhance HA removal. The flux was related to the adsorbent dosage and the optimal dosage for pre-deposition was $35.0g/m^2$. The dissolved organic carbon (DOC) removal of HA was 38.3%, 67.3% and 41.1% respectively when pre-deposited $35.0g/m^2$ $FeO_xH_y$, $MnFe_2O_4$ and $Fe_3O_4$ on membrane. Different adsorption effect of adsorbents on HA contributed to increasing of the flux at different level. Zeta potential of three adsorbents all decreased after adsorbed HA. The adsorption capacity of the three adsorbents was $FeO_xH_y$ > $MnFe_2O_4$ > $Fe_3O_4$. Atomic Force Microscopy (AFM) measurement showed the thickness of pre-deposition layers formed by different adsorbents was different. The scanning electron microscope (SEM) detection showed the morphology and compactness of pre-deposition layers formed by different adsorbents was different.

• 자원리싸이클링
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• 제7권3호
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• pp.36-41
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• 1998

본 연구에서는 도금폐수의 처리 및 폐굴껍질의 재활용 방안으로 폐굴껍질의 중화능과 중금속 흡착능을 Bohart-Adam 식에 의한 현장적용인자를 도출하여 향후 폐굴껍질과 유사한 성분을 함유하고 있는 수산폐기물의 재활용 가능성을 고찰해보고자 한다. 국내 해안 양식업 중에 비중이 높은 굴양식업은 다량의 폐굴껍질을 부산물로 발생시키며 이 폐굴껍질은 여러 가지 환경문제를 야기시키고 있다. 이러한 폐굴껍질은 약 93% 정도의 $CaCO_3$성분을 함유하고 있어 산성폐수의 pH 상승에 의한 중화능과 다공질체로서 중금속과 유기물에 대한 높은 흡착효율을 기대 할 수 있다. 여기서, 흡착탑의 사용시간과 흡착효율만 비교해 보면, 흡착탑의 사용시간은 Cr>Fe>Cu 순으로 나타났으나, 흡착효율은 Fe>Cr>Cu 순으로 나타났다. 이것은 흡착효율면에서 Fe이 Cr보다 우수하지만, Fe이 Cr에 비해 고농도이기 때문에 단시간에 배출기준농도에 도달함을 알 수 있다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.804-807
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• 2007

The acid gas removal (AGR) system was designed and installed to remove $H_2S$ in coal syngas in the pilot-scale coal gasification system for producing chemicals like Dimethyl Ether(DME). The syngas from the coal gasification at the rate of $100{\sim120$ $Nm^3$/hr included pollutants such as fly ash. $H_2S$, COS, $NH_3$, etc. The designed temperature and pressure of the AGR system are below 50oC and 8 kg/$cm^2$. Fe-chelate was used as an absorbent. $H_2S$ was stably removed below 0.5 ppm in the AGR system when the concentration of $H_2S$ was $150{\sim}450$ ppm. The pH of Fe-chelate solution was also stably maintained between $8{\sim}9$. FeMgO absorbent was also tested to remove $H_2S$ in the lab-scale AGR system and $H_2S$ was also removed below 0.5 ppm in the initial operation.

• Environmental Engineering Research
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• 제13권3호
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• pp.131-135
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• 2008

In this study, Fe(VI) was employed as a multi-functional agent to treat the simulated industrial wastewater contaminated with Cu(II)-EDTA through oxidation of EDTA, decomplexation of Cu(II)-EDTA and subsequent removal of free copper through precipitation. The decomplexation of $10^{-4}\;M$ Cu(II)-EDTA species was performed as a function of pH at excess concentration of Fe(VI). It was noted that the acidic conditions favor the decomplexation of Cu(II)-EDTA as the decomplxation was almost 100% up to pH 6.5, while it was only 35% at pH 9.9. The enhanced degradation of Cu(II)-EDTA with decreasing the pH could be explained by the different speciation of Fe(VI). $HFeO_4^-$ and $H_2FeO_4$, which are relatively more reactive than the unprotonated species $FeO_4^{2-}$, are predominant species below neutral pH. It was noted that the decomplexation reaction is extremely fast and within 5 to10 min of contact, 100% of Cu(II)-EDTA was decomplexed at pH 4.0. However, at higher pH (i.e., pH 10.0) the decomplexation process was relatively slow and it was observed that even after 180 min of contact, maximum ca 37% of Cu(II)-EDTA was decomplexed. In order to discuss the kinetics of the decomplexation of Cu(II)-EDTA, the data was slightly fitted better for the second order rate reaction than the first order rate reaction in the excess of Fe(VI) concentration. On the other hand, the removal efficiency of free Cu(II) ions was also obtained at pH 4.0 and 10.0. It was probably removed through adsorption/coagulation with the reduced iron i.e., Fe(III). The removal of total Cu(II) was rapid at pH 4.0 whereas, it was slow at pH 10.0. Although the decomplexation was 100% at lower pH, the removal of free Cu(II) was relatively slow. This result may be explicable due to the reason that at lower pH values the adsorption/coagulation capacity of Fe(III) is greatly retarded. On the other hand, at higher pH values the decomplexation of Cu(II)-EDTA was partial, hence, slower Cu(II) removal was occurred.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권1호
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• pp.86-93
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• 2016

Fenton is the reaction using the OH· radicals generating by interaction between hydrogen peroxide and Fe²⁺ which can oxidize the contaminants. Fe²⁺ ions are oxidized to Fe³⁺ ions by reaction with H₂O₂ and formed OH· radicals. UV-Fenton process includes the additional reaction that generates the OH· radicals by photodegradation of H₂O₂. In methylorange (MO) decolourization experiment with UV-Fenton, optimal Fe²⁺: H₂O₂ ratio was obtained at 1 : 10. Based on the obtained condition (H₂O₂= 10mM, Fe²⁺ = 1 mM) with/without UV-fenton experiment was carried out. Removal efficiency and sludge production were measured at 30 min. The case of w/o UV irradiation and only H₂O₂ was hardly treated and only Fe²⁺ showed 65% removal owing to coagulation. When UV-Fenton process in optimal ratio (Fe²⁺: H₂O₂ = 1 : 10), UV irradiation showed better removal efficiency than of w/o UV irradiation. Also, MO decolourization was a function of the hydrogen peroxide concentration (x₁), Fe²⁺:H₂O₂ ratio (x₂), and numbers of UV lamp (x₃) from the application of the response surface methodology. Statistical results showed the order of significance of the independent variables to be hydrogen peroxide concentration > numbers of UV l amp > Fe²⁺: H₂O₂ ratio.

• 환경위생공학
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• 제12권2호
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• pp.43-49
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• 1997

Iron and manganese problems in ground water affect far more water systems than almost any other water quality concern. The purpose of this study is to find the optimum condition of ozonation for the removal of dissolved iron, manganese and other organics in the polluted ground water. We proposed 4mg/l, 8mg/l as optimum ozone dose for the removal of $Fe^{2+},{\;}Mn^{2+}$, respectively. The removal efficiencies of $COD_{Mn}$ and $COD_{Cr}$ in ozone dose of 2mg/l - 6mg/l were about 40-50%. The removal efficiency of $NH_{3}-N$ was about 30-40% at pH8.5. In conclusion, it needs further systematic study and research concerned to treatability of $Fe^{2+},{\;}Mn^{2+}$ and biodegradability of organic compounds using Ozonation followed by biological filtration process in ground water treatment train.

• 한국광물학회지
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• 제27권4호
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• pp.207-222
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• 2014

폐-광석으로부터 금속구리분말을 회수하기 위하여 더미 미생물용출, Fe 제거와 전기분해실험을 수행하였다. Cu가 0.034% 함유된 폐-광석시료에 대하여 더미 용출실험을 수행한 결과, Cu 용출률은 박테리아 용출-용액에서 61%, 황산 용출-용액에서 62%로 나타났다. Fe를 효과적으로 제거하기 위하여 더미 용출-용액에 NaOH, $H_2O_2$ 및 $Ca(OH)_2$를 각각 적용한 결과 $H_2O_2$가 가장 효과적인 Fe 제거제로 선정되었다. 전해질 용액을 준비하기 위하여 $H_2O_2$를 더미 용출-용액에 처리한 결과 박테리아 용출-용액에서 Fe가 99%, 황산 용출-용액에서 60%로 제거된 반면에 Cu 제거율은 각각 5%와 7%로 나타났다. 이 용액에 대하여 전기분해 실험을 수행한 결과 Cu 회수율이 박테리아 용출-용액에서 98%, 황산 용출-용액에서 76%로 나타났다. 모수석 형태의 금속구리분말이 양쪽 용출-용액에서 회수되었다.

• 한국재료학회지
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• 제16권8호
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• pp.497-502
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• 2006

Recently, many attention have been focused on illite as a material for the well-being industry. Illite contains various kinds of iron bearing materials and they restrict their usage. In this study, Fe impurities in the illite produced in Yeongdong-gun, Chungcheongbuk-do were characterized and their removal experiments were performed. According to the characterization of illite raw ore, it contained 1.54 wt.%$Fe_2O_3$ due to the existence of iron oxide($Fe_2O_3$) and pyrite($FeS_2$). The raw ore was crushed into 3 mm or less using cone crusher and then ground by rod mill for the liberation of impurity mineral. For the removal of iron bearing minerals, an acid treatment, a flotation, a magnetic separation, and a flotation combined with magnetic separator were performed respectively. When the illite raw ore was treated with magnetic separation and various kinds of acid, 1.54wt.%. $Fe_2O_3$ content was reduced to 0.78 and 1.0 wt.%, respectively. On the other hand $Fe_2O_3$ content was reduced to be 0.52 wt.% after flotation. These results indicate that iron bearing minerals cannot be reduced below 0.3wt.%$Fe_2O_3$. However, combination of magnetic separation and flotation enable us to get 0.24wt.% of illite concentrate. It is concluded that, for the refinement of illite from Yeongdong-gun, the flotation combined with magnetic separation is good for high purity illite.

• 대한환경공학회지
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• 제31권7호
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• pp.541-548
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• 2009

본 연구에서는 매립장 침출수 같은 중금속과 유기물을 함께 함유하고 있는 폐수를 처리하기위하여, Fe(III)을 활성탄, 모래, 불가사리와 같은 담체에 첨착 및 코팅시킨 흡착제를 사용하였다. 제조된 Iron Impregnated Activated Carbon(Fe-AC), Iron Coated Sand(ICS), Iron Coated Starfish(ICSF)는 EPA 3050B 방법을 통하여 각 매질에 함유된 철 함량을 분석하였으며, 회분식 반응조에서의 흡착실험을 통하여 각 흡착제의 Mn(II), Zn(II) 및 Cu(II)의 제거성능을 비교하였다. Fe-AC 및 ICS의 철 함유량은 각각 1,612 mg/kg 및 1,609 mg/kg으로서 매우 유사하였으며 ICSF의 철 함유량은 1,768 mg/kg으로 ICSF의 철 코팅함량이 다른 두 가지에 비해 150 mg/kg 정도 높게 나타났다. 회분식 실험에서의 Mn(II), Zn(II), Cu(II)의 제거효율은 ICSF, Fe-AC, ICS의 순으로 높은 제거율을 보였다. 각 흡착제를 단일 및 다중층으로 충전한 칼럼반응기에 의한 연속식 실험결과, 단일 흡착제에 비해 ICS, Fe-AC, ICSF의 순으로 충전한 시스템에서 높은 중금속 및 페놀제거효율을 나타내었으며, Cu(II)와 Zn(II)에 대해서는 뚜렷한 파과능을 보였으나 Mn(II) 제거율은 상대적으로 낮게 나타났다. 각 흡착제를 병합 충전한 다중층 칼럼반응시스템은 중금속 및 phenol제거에 효과적임을 알 수 있었다.

• 상하수도학회지
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• 제30권1호
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• pp.87-97
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• 2016

First of all, Fe or/and Mn immobilized granular activated carbons (Fe-GAC, Mn-GAC, (Fe, Mn)-GAC) were synthesized and tested to remove arsenate (As(V)). The results in batch test indicated that Fe-GAC removed As(V) effectively, even though the surface area of Fe-GAC was reduced largely. Moreover, adsorption isotherm test indicated that the experimental data fit well with Langmuir model and the maximum adsorption capacity ($q_{max}$) of Fe-GAC for As(V) was $3.49mg\;g^{-1}$, which was higher than GAC ($2.24mg\;g^{-1}$). In column test, the simulated water, which consisted of As(V), Fe(III), Mn(II) and Ca(II) in tap water, was used. Fe-GAC column with 1 hr of pre-washing time treated As(V) effectively while GAC column removed Fe(III) better than Fe-GAC column. Moreover, the increasing pre-washing time from 1 to 9 hour in Fe-GAC column enhanced Fe(III) removal with little negative impact of As(V) removal. Mostly, the column filled with Fe-GAC and GAC (i.e. the mass ratio of Fe-GAC:GAC = 2:8) showed the higher treatability of both As(V) and Fe(III), even it operated with 1 hr pre-washing time.