• 대한환경공학회지
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• 제35권12호
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• pp.973-977
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• 2013

이 연구는 전기화학적 활성을 갖는 미생물들을 알아내기 위하여 농화배양 단계에서 시간에 따라 미생물연료전지의 미생물 군집 변화를 알아본 것이다. 접종원으로 하수처리장 혐기 소화액와 가축분뇨를 1 : 1로 혼합한 액을 사용하였다. 농화배양 과정에서 미생물 생장곡선에 따라 지체기, 대수성장기 그리고 정지기로 전류발생 패턴을 보면서 구분하였다. 전류가 안정적으로 발생되는 시점을 농화배양이 끝난 시점으로 판단하였으며, 이때 전류는 $0.84{\pm}0.06mA$가 발생되었다. 농화배양이 되어 가는 과정에서 미생물군집 변화를 전기영동(DGGE)에서 확인하여 시간에 따라 새롭게 나타나는 band나 농도가 높아지는 band 17개를 잘라내어 염기서열을 분석하였다. 이 결과 지체기와 대수성장 단계에서는 Clostridium, Rhodocyclaceae, Bacteriodete 그리고 Uncultured bacterium 등이 검출되었고, 정지기에서는 Geobacter sp., Rhodocyclaceae, Candidatus, Nitrospira, Flavobactriaceae, 그리고 Uncultured bacterium 등이 검출되었다. Geobactor의 경우는 이미 전기활성 미생물로 알려져 있는 미생물 종으로 이를 포함하여 이 연구에서 검출된 다른 미생물들 중에도 전기활성이 있는 미생물을 포함하고 있을 것으로 판단된다.

• 한국환경보건학회지
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• 제34권5호
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• pp.387-394
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• 2008

The toxicity of methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA) and formaldehyde (FA) on the indigenous microbial community in forest soil was studied. MTBE, TBA and FA with different concentrations were added into microcosms containing forest soil samples. After 10 and 30 days, total viable cell number and dehydrogenase activity in the microcosms were evaluated. Bacterial communities in the microcosms were also analyzed using a denaturing gradient gel electrophoresis (DGGE). Dehydrogenase activity and total viable cell number were decreased according to the increase of MTBE, TBA and FA concentrations (P<0.05). FA toxicity was the highest, but TBA toxicity was the lowest. The results of principal component analysis using DGGE fingerprints showed that the microbial communities contaminated MTBE, TBA and FA were grouped by exposure time not exposure concentration. Dominant species in the microcosms were as follows: Photobacterium damselae sub sp. and Bacillus sp. KAR28 for MTBE; Mycobacterium sp. and Uncultured Clostridium sp. for TBA; and Uncultured Paenibacillaceae bacterium and Anxynobacillus, Flavithermus for FA.

• KSBB Journal
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• 제26권5호
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• pp.407-411
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• 2011

Microbial fuel cell (MFC) wes enriched using sludge in wastewater treatment. The microbial community of activated sludge and enriched MFC were analyzed by FISH (fluorescent in situ hybridization) and 16S rDNA sequencing. Bacteroidetes group were pre-dominant in activated sludge by FISH. ${\alpha}$ group, ${\gamma}$ group and Acintobacter group were dominant and they were similar to distribution. The average value of 10 peak of MFC is 0.44C. When MFC wase enriched by sludge, ${\gamma}$-Proteobacteria, Plantomycetes group increased 70% and 60%, respectively. In results of 16S rDNA sequencing, Sphiringomonas sp. was comprised in ${\alpha}$ proteobacteria and Enterobacter sp., Klebsiella sp., Acinetobacter sp., Bacillus sp. were comprised in ${\gamma}$ proteobacteria and Chryseobacterium sp. was comprised in Flavobacteria were isolated from sludge.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1965-1971
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• 2016

Livestock wastewater containing high concentrations of ammonium and nitrate ions was pretreated with microbubbles and an Fe/MgO catalyst prior to its application in microbial fuel cells because high ion concentrations can interfere with current generation. Therefore, tests were designed to ascertain the effect of pretreatment on current generation. In initial tests, the optimal amount of catalyst was found to be 300 g/l. When 1,000 ml/min $O_2$ was used as the oxidant, the removal of ammonium- and nitrate-nitrogen was highest. After the operating parameters were optimized, the removal of ammonium and nitrate ions was quantified. The maximum ammonium removal was 32.8%, and nitrate was removed by up to 75.8% at a 500 g/l catalyst concentration over the course of the 2 h reaction time. The current was about 0.5 mA when livestock wastewater was used without pretreatment, whereas the current increased to $2.14{\pm}0.08mA$ when livestock wastewater was pretreated with the method described above. This finding demonstrates that a 4-fold increase in the current can be achieved when using pretreated livestock wastewater. The maximum power density and current density performance were $10.3W/m^3$ and $67.5W/m^3$, respectively, during the evaluation of the microbial fuel cells driven by pretreated livestock wastewater.

• 한국수소및신에너지학회논문집
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• 제19권6호
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• pp.498-504
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• 2008

Metal-reducing bacterium, Geobacter sulfurreducens is available for mediator-less microbial fuel cell (MFC) because it has biological nanowires(pili) which transfer electrons to outside the cell. In this study, in the anode chamber of the MFC system using G. sulfurreducens, the concentrations of NaCl, sodium phosphate and sodium bicarbonate as electrolytes were mainly optimized for the generation of electricity from acetate. 0.4%(w/v) NaClO and 0.5M $H_2SO_4$ could be utilized for the sterilization of acrylic plates and proton exchange membrane (major construction materials of the MFC reactor), respectively. When NaCl concentration in anode phosphate buffer increased from 5 to 50 mM, power density increased from 6 to $20\;mW/m^2$. However, with increasing sodium phosphate buffer concentration from 5 to 50 mM, power density significantly decreased from 18 to $1\;mW/m^2$. Twenty-four mM sodium bicarbonate did not affect electricity generation as well as pH under 50 mM phosphate buffer condition. Optimized anode chamber of MFC using G. sulfurreducens generated relatively high power density ($20\;mW/m^2$) with the maximum coulombic efficiency (41.3%).

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3399-3402
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• 2010

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.438-441
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• 2005

A mediator-less microbial fuel cell (MFC) was used to determine the performance effects of a membrane­electrode assembly (MEA). The MFC with an MEA generated a higher current with an increased coulomb yield when compared to an MFC with a separate cathode. Less oxygen was diffused through an MEA than through a Nafion membrane. The MFC performance was improved with a buffer, although a high-strength buffer reduced the performance.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
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• pp.175-176
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• 2003

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.2025-2030
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• 2010

When $Cu^{2+}$ was used as an electron acceptor, removal of $Cu^{2+}$ was achieved from the synthesized wastewater (SW) in the cathode compartment of a microbial fuel cell (MFC). By addition of $KNO_3$, the different initial pH of the SW showed no effect on the removal efficiency of $Cu^{2+}$. For $Cu^{2+}$ concentration of 50 mg/L the removal efficiencies were found to be 99.82%, 99.95%, 99.58%, and 99.97% for the $KNO_3$ concentrations of 0, 50, 100 and 200 mM, and to be 99.4%, 99.9%, 99.7%, and 99.7% for pH values of 2, 3, 4, and 5, respectively. More than 99% $Cu^{2+}$ was removed for the $Cu^{2+}$ concentrations of 10, 50, and 100 mg/L, while only 60.1% of $Cu^{2+}$ was removed for the initial concentration of 200 mg/L (pH 3). The maximum power density was affected by both $KNO_3$ concentration and initial concentration of $Cu^{2+}$. It was increased by a factor of 1.5 (from 96.2 to 143.6 mW/$m^2$) when the $KNO_3$ concentration was increased from 0 to 200 mM (50 mg/L $Cu^{2+}$), and by a factor of 2.7 (from 118 to 319 mW/$m^2$) when $Cu^{2+}$ concentration was increased from 10 to 200 mg/L (pH 3).

• KEPCO Journal on Electric Power and Energy
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• 제2권4호
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• pp.589-593
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• 2016

미생물연료전지(Microbial Fuel Cell; MFC)는 전기화학활성미생물로 불리는 미생물을 촉매로 이용하여, 유/무기물의 산화환원 반응을 통해서 전기에너지를 생산할 수 있는 장치이다. 단일 MFC에서 발생하는 낮은 전기생산량을 극복하기 위해, 다수의 형태의 MFC를 직렬 또는 병렬로 연결하는 방법이 연구되고 있다. 본 연구에서는 6개의 단위 막전극접합체(Separator Electrode Assembly; SEA)로 구성된 침지평판형과 직립평판형 MFC 스택을 운전하였다. 단위 MFC와 MFC 스택의 전기발생량을 비교하였으며, 이를 통해서 MFC의 최적 스택기술을 확보하기 위한 기초자료로 활용하고자 하였다. 모든 SEA가 산화전극부를 공유하고 있는 침지평판형 MFC의 경우, 직렬과 병렬을 함께 사용할 경우, 단일 연결 방식을 사용하는 것보다 전압의 손실이 더 크게 나타났으며, 단일 연결방법 중 병렬연결 하는 것이 손실을 최소화 할 수 있는 것으로 나타났다. 직립평판형 MFC의 경우, 산화전극부를 공유하고 있는 SEA만 직렬 연결할 경우에는 전압의 손실이 크게 나타났으며, 산화전극부를 공유하고 있는 SEA간에 병렬 연결 후, 병렬 연결된 SEA를 직렬연결하는 방식이 전압의 손실을 최소화 할 수 있을 것으로 나타났다.