• 멤브레인
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• 제15권2호
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• pp.85-104
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• 2005

Recently, membrane can be prepared by two methods, phase inversion and electrospinning techniques. Phase inversion technique is a conventional but commercially preparation membrane. The most versatile of preparation in this technique is immersion of the cast film into nonsolvent bath, causing dense top layer with a finger-like pattern in the sub layer membrane. The membrane pore size getting from phase inversion is in the range of micro or submicrometer. As a result, it can be used as microfiltration and ultrafiltration applications. A new technique, electrospinning, is introduced for membrane preparation. Nonwoven nanofibrous mat or nanofibrous membrane is obtained. In this technique, electrostatic charge is introduced to the solution jet, causing a thin fiber with high surface area; hence it can be used in the applications where high surface area-to-volume or length-to-diameter ratios are required. Moreover, the pore size can be controlled by controlling the time of electrospinning. Hence, it can be used as a filter for filtering microparticles as well as nanoparticles.

• KSBB Journal
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• 제5권2호
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• pp.159-165
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• 1990

Ethanol fermentation by Scccharomyces cervisiae was carried out in the cell recycle filter system with a cheap fabric filter having a pore size of 10${\mu}$m. Maximum biomass concentrations up to 85g/1 were obtained, but in practice operational concentrations were between 50 and 80g/1. Ethanol productivity was 42g/1-hr, with an ethanol concentration of 66g/1 and an ethanol yield of over 86%. Continuous operation was possible by applying periodic backflushing. The ethanol fermentation could be carried out without difficulty at a dilution rate up to 0.8h-1 In order to obtain a high cell concentration and ethanol productivity, development of filter module with the larger filtration area is required.

• 미생물학회지
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• 제28권3호
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• pp.188-191
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• 1990

The streptococcal plasmid pAM$\beta_{1}$ (erythromycin resistance)was transferred via conjugation from Streptococcus faecalis DS 5 to Lactobacillus casei YIT 9018 by a filter mating method. The transfer frequency depended greatly on the type, pore size and side(front or back) of membrane filter. Water passing through a membrane under reduced pressure induced very tight contact between the cells, increased the transconjugation frequency about 1.3 to 37-fold when Millipore membrane filter (0.45.$\mu$m, front side up) was used.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2004년도 추계학술대회
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• pp.272-273
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• 2004

Filter media are one of themost important choices when bilfiltration is applied. Filter media provide adsorbing microbes with available sites for residence and the residential cells grow to degrade or decompose target waste gases. Up to date, filter media were only qualitatively analyzed. As a quantitative approach to filter material for biofiltration, a simple model based on reaction kinetics and mass action law (Ottengraf's Model in 1983) was presented. Cork, zeolite, and granulated activated carbon were tested in terms of effective surface area, cell covered fraction of adsorbing sites, surface roughness, and pore size distribution. The cell covered fraction, surface roughness and hydrophilicity was found to be closely related to the efficiency of gas degradation in biofiltration. The cork was the best candidate for cell residence and growth in this work.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.326-328
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• 2001

Pseudomonas diminuta (ATCC 19146) has been typically used in the bacterial challenge test for validation of the sterilizing filtration process. Cell size is critical for determining the retention characteristics of membrane filters with pore-size of $0.2{\mu}m$. The changes of cell sizes after osmotic shocks at 150, 260, 500, and 700 mosM were measured by a particle size analyzer and the changes of their buoyant densities were analyzed with a Percoll gradient. The results indicated that there were no significant differences when cells were cultured in 260 mosM medium and osmotically shocked at 500 and 700 mosM. However, the osmotically shocked cells at 150 mosM showed a 38% increase of the cell size compared to the cells at 260 mosM. From these study, we concluded that the worst case condition for validation of a sterilizing filter would be 500 mosM, not because of changes in the cell size, but due to decrease in cell viability under those conditions.

• 대한환경공학회지
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• 제37권3호
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• pp.165-174
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• 2015

강우시 표면유출에 의해 지표수에 유입되는 우수에는 토사를 포함한 각종 비점오염 물질이 다량 포함되어 있으며 이는 지표수의 수질관리에 부정적인 영향을 미치고 있다. 유역의 오염물질이 수계에 도달하기 전에 처리하는 것이 바람직하며 따라서 강우유출수를 처리하는 다양한 방법들이 시도되고 있다. 그러나 일반적인 빗물오염 제어시설 및 장치들은 설치 및 유지관리를 위해 많은 노력과 비용을 요구하는 문제점 가지고 있다. 본 연구에서는 유역의 초기우수에 의한 오염을 제어하기 위해 경제적으로 타당하고 설치 및 관리가 용이한 섬유 필터를 이용하여 부유물질을 제거할 수 있는 방법을 개발하였다. 여재는 경제적이면서 내구성이 우수한 폴리에스터계열의 섬유 필터를 사용하였으며, 연구 대상지역 강우유출수의 입도분석 결과에 따라 $20{\mu}m{\sim}94{\mu}m$ 범위에서 다양한 공극의 여재에 대한 성능을 실험을 통해 분석하였다. 수두별 여과성능을 분석하기 위한 실험 장치를 고안 제작하여 필터 공극에 따른 섬유 필터의 TSS 제거 효율을 평가 하였다. 수두가 높을수록 여과속도가 증가하는 것을 확인하였으며 공극별 여과 속도를 측정하여 분석하였다. 섬유 필터의 공극 크기가 작을수록 TSS 제거효율이 증가되었으나, 공극별 TSS 제거 효율은 대체적으로 양호하나 유사한 편으로서 TSS의 대부분의 질량은 입자의 크기가 큰 부분에 치중되어 있는 것이 주요 원인으로 분석된다.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.60-67
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• 2008

The catalytic filter of Cu-ZSM5/alumina beads was considered to reduce NOx in the urea SCR system. Catalytic support of porous alumina beads with mean pore size $130{\mu}m$ and porosity $75{\sim}83%$ were prepared using foaming and gel-casting method. The Cu-ZSM5 catalysts were coated on the supporting alumina beads using $Cu(NO_3)_2$ by ion exchange method. After a washcoating process was applied to coat 10w% Cu-ZSM5 on porous alumina bead, coating layer was estimated $20{\mu}m$ in thickness. The characterization and the feasibility as a catalytic supports were investigated. And the NOx conversion test in Cu-ZSM5/Alumina Beads filter system was conducted by using Urea as reductants under laboratory test. The NOx conversion was increased as size and porosity of beads and observed more than 95% excellent NOx conversion above $300^{\circ}C$.

• Journal of Biosystems Engineering
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• 제32권4호
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• pp.263-268
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• 2007

An auto sampling and filtering unit was developed for monitoring automation of a fermentation process and its performance was evaluated. The automatic sampling and filtering unit was constructed with a glass filter, a diaphragm suction pump, and a flow direction change valve. To evaluate operating stability, delivery volumes of the suction pump were measured according to the experimental conditions of cellulose powder, pore size of the glass filter and suction head of the pump. The developed unit could deliver the sample solution under any experimental conditions except the filter pore size of $16{\mu}m$ and the suction head of 20cm. In case of the suction head of 30cm, the pump could not deliver the sample solution at all. Concentrations of the sample solutions were converged on those of the standard glucose solution after 8 minutes from the initial sampling time. The relative error of concentration between the sample and the standard solution showed 3.8, 4.8, 7.0% for the 1, 3, 5% contents of cellulose powder, respectively.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.173-176
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• 2002

With the introduction of high-tech industries, these days textile products used as advanced materials of semiconductor, transport and medical fields. It was concerned with environmental problem in textile industry lately. So the problem is receiving careful study for high effectiveness and high efficiency of filter media made by nonwoven fabric to get rid of a pollutant. PET filter media produced from conventional methods can not precisely filtrate small particles, because conventional PET filter media has too large pore size. (omitted)

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.260-263
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• 2000

대량발효 후 미세여과막과 MWCO 100K, 50K의 한외여과막을 이용한 막분리시스템을 적용하여 MTGase를 분리한 결과 pore size 1.6, $0.7\;{\mu}m$의 cellulose fiber 재질의 예비여과막과 $0.45\;{\mu}m$ cellulose acetate재질의 미세여과막을 이용하여 얻어진 분리액을 MWCO 100K와 50K를이용하여 농축시킨 결과 enzyme의 농도가 1.29 units/ml, 효소 비활성도는 약 0.2 units/mg protein 으로 나타났으며 초기 배양액에 비해 3.7배의 농축효과를 보였다.