• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.277-284
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• 2005

Micro-filtration (MF) or ultra-filtration (UF) system with hollow-fiber cartridge was introduced in order to improve the Quality level of commercial foxtail millet Yakju, which has an off-flavour and/or undesired colour after the thermal treatment. The filtration effects of cartridges such as MF (0.65, 0.45, 0.2, 0.1 $\mu$m) and UF (500 K dalton) were investigated. The physicochemical and sensory characteristics of the Yakju were then evaluated during the 6 months storage at room temperature. The exclusion ability of microorganism in samples was confirmed in all cartridges, but 0.45 pm MF-cartridge was suitable in the Yakju manufacture due to its superior filtration rate and efficiency. Changes in reducing sugar and colour difference of foxtail millet Yakju untreated or treated by heat ($65^{\circ}C$${\times}$10 min) were observed during the storage; after 6 months the L-value of thermal-treatment sample was decreased and its b-value, however, significantly increased so that its color became dark, in comparison to non-thermal treatment sample. This decrease of reducing sugar is assumed that color change is associated with non-enzymatic browning reaction. Sensory Quality of foxtail millet Yakju produced by non-thermal treatment was better than that of thermal treatment.

• Natural Product Sciences
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• v.20 no.1
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• pp.58-64
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• 2014

In this study, edible protopanaxadiol saponin enriched fraction were prepared by ultrafiltration (UF). Ginseng extract was prepared from mixtures of ginseng main root and rootlet (root: rootlet = 4 : 6). UF system was used the four-piston Diaphragm pump equipped with 5 kDa pore size Hydrosart Cassette made by regenerated cellulose acetate (CA) or 3 kDa pore size Hollow Fiber cartridge made by polyethersulfone (PES). Total ginsenoside contents of concentrated fraction by UF system was found to higher, compared to before those of untreated method. Especially, processing of UF showed the increase of PPD-type ginsenoside, while PPT-type ginsenoside was gradually decreased by both 3 kDa and 5 kDa membrane. After removal of 80% water by the 5 kDa Hydrosart Cassette and by 3 kDa Hollow Fiber cartridge, ginsenoside Rb1 content was higher 37.2 mg/g and 25.3 mg/g than 20.8 mg/g in untreated process. The ratio of Rb1 to Rg1 (Rb1/Rg1) and PPD- to PPT- type ginsenoside (PPD/PPT) were higher in inner fluid of ginseng extract after UF by 3 kDa cartridge (47.1 and 23.5, respectively) and 5 kDa Cassette (25.3 and 11.9, respectively) than those of before UF (5.7 and 3.7, respectively). PPD-type ginsenoside enriched fraction by UF system could be developed as a new ginseng material in food and cosmetic industrials.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.47-53
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• 2011

$SF_6$ (Sulfur hexafluoride) possesses high GWP (Global Warming Potential) as sepcified by the IPCC (Intergonvernmental Panel of Climate Change). Recently, the recovery-separtion of $SF_6$ research area, including permeation properties studies using various membrane's materials and the practical operation of recovery-separtion using membrane of waste $SF_6$ gas is in the initial state. The separation efficiency of a single $SF_6$ and waste $SF_6$ mixture was evaluated using a PSF (polysulfone), PC (tetra-bromo polycarbonate) and PI (polyimide) hollow fiber membranes. According to the results of single gases permeation properties, PI membrane has the highest permselectivity of $N_2$ gas in $N_2/SF_6$ gas. Under the condition of P=0.5 MPa, the highest concentration of recovered $SF_6$ is 95.6 vol % in the separation experiment of $SF_6/N_2$ mixture gas by PC membrane. Under the operation pressure of P=0.3 MPa at a fixed retentate flow rate fixed of 150 cc/min, the maximum recovery efficiency of $SF_6$ is up to 97.8% by PSF membrane. From the results above, it is thought that the separation and recovery technique of $SF_6$ gas using membrane will be used as the representative eco-technology in the $SF_6$ gas treatment in the future.

• Membrane Journal
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• v.25 no.5
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• pp.385-390
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• 2015

To determine the pervaporation separation characteristics of IPA/water mixtures, PEI/PDMS hollow fiber membrane module commercialized by Airrane Co. was subjected to both lab and pilot tests. The flux of $0.52kg/m^2h$ and IPA concentration of 68.5% at $25^{\circ}C$ were obtained whereas the $1.368kg/m^2h$ and 61.2% were measured at $55^{\circ}C$. In order to realized the durability of the module, the long-term test (at $50^{\circ}C$) of 100 days has been conducted and as a result, the flux $1.03{\sim}1.15kg/m^2h$ and IPA concentration 61.8~62.5% were maintained with the initial values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.2
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• pp.114-119
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• 2003

This study is to remove several organic pollutants from wastewater by non-dispersive membrane solvent extraction technique. The distribution coefficients of several solvents were determined and the experimental system was operated counter-currently and cocurrently with respect to the aqueous phase and solvent. In these experiments, as the flow rate of aqueous solution inclosed, due to being shortened contact time to solvent, the rate of removal of organic pollutants decreased and as the flow rate of solvent increased, the rate of removal increased. Meanwhile, the rate of removal of organic pollutants for the countercurrent flow system was higher than that for the occurrent flow system.

• Prospectives of Industrial Chemistry
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• v.14 no.3
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• pp.25-36
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• 2011

압축공기 중의 수분은 공압설비의 모든 요소에 중대한 해를 입히며 밸브의 고착, 계기의 막힘 또는 공압기기의 오작동을 일으키며 생산하는 제품의 질에 있어서도 많은 해를 입혀서 제품의 질을 떨어뜨리는 역할을 하게 된다. 따라서 수분을 제거하는 방법이 필요하며 기존의 냉동식 및 흡착식을 대신하여 분리막 법이 적용될 수 있다. 현재 제습용 기체분리막 모듈은 적용이 시작된 단계에 있다. 제습용 기체분리막은 의료기기, 분석기기, Instrument air 장비에 응용이 진행되고 있다. 최근 들어 선진각국 뿐만 아니라 국내에서도 막소재 개발, 복합막 개발, 모듈 개발, 시스템 설계 및 제작 기술 개발이 진행되고 있다. 현재로서는 제습막공정에 적합한 막소재의 개발이 시급하지만 이후 적용확대를 위해서는 제습용 기체분리막의 신뢰성 향상을 위한 다각도의 노력이 필요하다.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.65-74
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• 1997

The purpose of this study was to investigate the removal effect and variation of contaminated water by various water treatment processes using sediment filter, activated carbon, photocatalysis, reverse osmosis, ultra violet sterilizer and ultra filtration. The removal effect of chloride and trace metal was low by activated carbon and ultra filter but high in reverse osmosis. The removal effect of bacteria and E. coli was low by activated carbon and membrane filter system using activated carbon but high in impregnated activated carbon. The removal effect of TCE was low in sand and ultra filter system as compared with activated carbon. Ultra filtration process was effective for purify agricultural water without E.coli. Reverse osmosis was effective to remove heavy metal and activated carbon was effective to remove halogenated organic chemical compound. The flux and the removal effect of COD in spiral wound ultrafilter were higher than the hollow fiber ultrafilter.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.76-78
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• 2001

먹는 물에 존재하는 크립토스포리디움 및 지아디아등 기존의 표준 정수처리 공정에 의해 제거가 용이치 않은 원생동물 둥을 채집할 수 있는 미생물 검출 캡슐을 개발하였다. 본 장치의 여과필터는 고분자물질을 소재로 한 중공사 형태(Hollow Fiber Membrane)로 유효여과면적을 크게하였고, Pore size는 0.1㎛이다. 채집캡슐은 탁도에 따른 투과수량은 일차의 상관관계를 나타내며, 시간당 20ℓ를 투과시킬 때 탁도 7.0 NTU까지 가능함을 확인 할 수 있었다. 일차 시제품은 89.6-94.6%의 크립토스포리디움 및 72.6-78.6%의 지아디아 포낭을 회수하였고, 이차 시제품은 92.5-93.7%의 크립토스포리디움 및 81.3-88.2%의 지아디아 포낭을 회수하는 것으로 나타났다. 동일한 조건에서 외국제품은 84.0%의 크립토스포리디움 및 66.7%의 지아디아 포낭을 회수하는 것으로 나타났다.

• Membrane Journal
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• v.17 no.1
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• pp.54-60
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• 2007

In this research, the cation-exchange membrane (SS membrane) containing sulfonic acid group was prepared by radiation induced grafted polymerization onto a porous hollow fiber membrane to effectively remove ammonia which was produced by urea decomposition for peritoneum dialysis system. And the metal ionic cross-linking cation-exchange membrane (SS-M membrane) was prepared by the adsorption of metallic ions (Cu, Ni, Zn) to the SS membranes. The pure water flux and adsorption capacities of ammonia to SS and SS-M membranes were examined. The pure water flux of SS membrane decreased rapidly with the density of $SO_3H$ group increasing. As the metallic ions were adsorbed to the SS membrane, the pure water flux was increased. The adsorption capacities of ammonia at the SS membrane increased with increasing of density of $SO_3H$ group. The ion-exchange capacity of ammonia of the SS membrane was approximately proportional 1 : 1 to the density of $SO_3H$ group. The SS membrane had higher adsorption capacities than the SS-M membrane. The highest adsorption capacities of SS and SS-M membrane appeared the highest pH 9.

• Membrane Journal
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• v.26 no.2
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• pp.126-134
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• 2016

To produce renewable biomethane from biogas, the properties of physical absorbents such as water, methanol, 1-methyl-2-pyrrolidone (NMP), poly(ethylene glycol) dimethylether (PEGDME), and propylene carbonate (PC) were studied, and PC was applied to membrane contactor systems. Among physical absorbents, PC exhibited a high contact angle of $58.3^{\circ}$ on polypropylene surface, and a PC/water mixture (5 wt%) increased the contact angle to $90^{\circ}$. Furthermore, the PC/water mixture presented higher $CO_2$ absorption capacities (0.148-0.157 mmol/g) than that of water (0.121 mmol/g), demonstrating a good property as an absorbent for membrane contactors. Actual operations in membrane contactors using the PC/water mixture resulted in $CO_2$ removal of 98.0-97.8% with biomethane purities of 98.5-98.3%, presenting a strong potential for biogas treatment. However, the PC/water mixture yielded moderate improved in $CO_2$ removal and methane recovery, as compared with water in the membrane contactor operation. This is originated from insufficient desorption processes to reuse absorbent and low $CO_2$ flux of the PC/water absorbent. Thus, it is requiring optimizations of membrane contactor technology including development of absorbent and improvement of operation process.