• Proceedings of the Membrane Society of Korea Conference
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• 1991.04a
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• pp.23-26
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• 1991

산업화, 선진화 및 인구의 급격한 도시집중화 현상 등으로 인하여 생활 및 공업 용수의 사용량은 급증하고 있으며, 이로인한 하.폐수의 발생량도 증가하고 있다. 그렇지만 한정된 수자원을 가지고 용수 확보를 위한 댐등의 건설도 한계가 있으며, 또한 하.폐수의 방류로 인한 환경오염의 측면도 신중히 다루어져야 한다. 이와 같은 문제점을 해결하기 위한 한가지 방법으로써 하.폐수 재활용 공정이 이용될수 있으며, 최근 역삼투막 system을 이용한 재활용 공정이 활발한 연구와 실제 적용 사례를 통하여 적용가능성을 입증하고 있다.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.09a
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• pp.105-120
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• 1996

본 발표에서는 세계적으로 가장 안전한 물처리방법으로 인정받고 있는 R/O막에 대하여 개발역사, 제조공정 및 설비에 대하여 소개하였다. 그리고 국내에서 최초로 개발된 제일합섬의 "CSM" R/O membrane과 전세계적으로 널리 사용되고 있는 R/O막에 대한 각 Grade 및 믈성에 대하여 설명하고, 종류에 따라서 NaCl, MgSO$_{4}$, 질산성 질소, 6가 크롬의 제거능력실험을 통하여 용도에 맞는 R/O막의 선책기준을 제시하였다. 또한, R/O막으로 먹는물 처리 System을 설계할 수 있는 간단한 Procedure 및 R/O system운전의 가장 큰 문제점인 Fouling의 생성과정 및 제거방법에 대하여 소개하고 미국 및 일본의 R/O막을 이용한 먹는물 처리 System실적에 대하여 언급하였다.대하여 언급하였다.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.373-383
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• 2018

Fouling by solids and microorganisms is the major obstacle limiting the efficient use of membrane wastewater treatment. In our previous study, two stages microalgae/membrane filtration system was proposed to treat anaerobic digested palm oil mill effluent (AnPOME). This two stages microalgae/membrane filtration system had showed great potential for the treatment of AnPOME with high removal of COD, $NH_3-N$, $PO_4{^{3-}}$, TSS, turbidity, and colour. However, fouling behavior of the membrane in this two stages microalgae/membrane filtration system was still unknown. In this study, empirical models that describe permeate flux decline for dead-end filtration (pore blocking - complete, intermediate, and standard; and cake layer formation) presented by Hermia were used to fit the experimental results in identifying the fouling mechanism under different experimental conditions. Both centrifuged and non-centrifuged samples were taken from the medium with 3 days RT intervals, from day 0 to day 12 to study their influence on fouling mechanisms described by Hermia for ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) filtration mode. Besides, a more detailed study on the use of resistance-in-series model for deadend filtration was done to investigate the fouling mechanisms involved in membrane filtration of AnPOME collected after microalgae treatment. The results showed that fouling of UF and NF membrane was mainly caused by cake layer formation and it was also supported by the analysis for resistance-in-series model. Whereas, fouling of RO membrane was dominated by concentration polarization.

• Membrane Journal
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• v.22 no.3
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• pp.155-170
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• 2012

Fuel cells have been considered as alternative power generation system in the twenty-first century because of eco-friendly system, high power density and efficiency compare with petroleum engine system. Proton exchange membranes (PEMs) are the key components in fuel cell system. Currently, Nafion has been used in fuel cell system. However, Nafion has disadvantages such as low conductivity at high temperature and high cost. The researchers have focused to reach the high properties such as high proton conductivity, low permeability to fuel, good chemical/thermal stability, good mechanical properties and low manufacturing cost. Various methods have been developed for preparation of proton exchange membrane with high performance and commercialization of fuel cell system. The hybrid organic/inorganic membrane has the potentials to provide a unique combination of organic and inorganic properties with improved proton conductivity and mechanical property at high temperatures. So, this paper presents an overview of research trend for the composite membranes prepared by organic/inorganic system using various inorganic materials.

• Membrane Journal
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• v.26 no.1
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• pp.14-25
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• 2016

The membrane separation process is growing very fast because of the high efficiency and low cost compared with other traditional process. The membrane process consists of various components such as membrane, module and mechanical part. The requirements for materials used in the membrane separation are becoming more and more demanding for achievement of high efficiency. Membrane module is also considered as the one of the key component in the membrane system. Recently composite materials have been considered as the membrane housing due to their excellent property and low cost compared with stainless module. In this review, a various types of glass fiber and composite material are summarized and their potential for the application of membrane system is discussed.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.51-52
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• 1994

High permeability, selectivity and stability are the basic properties also required for membrane gas separations. The $CO_2$ separation by liquid membranes has been developed as a new technique to improve the permeability and selectivity of polymeric membranes. Sirkar et al.(1) have atlempted the hollow-fiber contained liquid membrane technique under four different operational modes, and permeation models have been proposed for all modes. Compared to a conventional liquid membrane, the diffusional resistance decreased by the work of Teramoto et al.(2), who referred to a moving liquid membrane. Recently, Shelekhin and Beckman (3) considered the possibility of combining absorption and membrane separation processes in one integrated system called a membrane absorber. Their analysis could be predicted effectively the performance of flat sheet membrane, however, there are restrictions for considering a flow effect. The gas absorption rate is determined by both an interfacial area and a mass transfer coefficient. It can be easily understood that although the mass transfer coefficients in hollow fiber modules are smaller than in conventional contactors, the substantial increase of the interfacial area can result in a more efficient absorber (4). In order to predict a performance in the general system of hollow-fiber membrane absorber, a gas-liquid mass transfor should be investigated inevitably. The influence of liquid velocity on both a mass transfer and a performance will be described, and then compared with experimental results. A present study is attempted to provide the fundamentals for understanding aspects of promising a hollow-fiber membrane absorber.

• Membrane Journal
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• v.23 no.4
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• pp.257-266
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• 2013

The main purpose of this study is to develop a commercial scale of pervaporative process equipped with hollow fiber membrane modules, being able to effectually purify organic solvent at high temperature well over its boiling point under high vapor pressure. Three constituent technologies have been developed; 1) to fabricate braid-reinforced hollow fiber membrane stable in high pressure and high temperature application, 2) to design and fabricate a commercial scale of hollow fiber membrane module, and 3) to design and fabricate a pilot scale of pervaporation equipment system. The developed hollow fiber membrane possesses a membrane performance superior to the membrane of Sulzer (Germany) which is the most-well known for pervaporation process, and the membrane module equips hollow fiber membranes of $4.6m^2$ and the pervaporation system can treat organic liquid at 200 L/h, which is based on the dehydration of 95 wt% isopropyl alcohol (IPA). Since the membrane module is designed to flow in and pass through the inside of individual hollow fiber membrane, not to involve both the formation of feed's dead volume observed in flat-sheet membrane module and the channeling of feed occurring inside hollow fiber bundle which lower membrane performance seriously, it showed excellent separation efficiency. In particular, the module is inexpensive and has less heat loss into its surrounding, in compared with flat-sheet membrane module. In addition, permeant can be removed effectively from the outer surface of hollow fiber membrane because the applied vacuum is conveyed uniformly through space between fibers into respective fiber, even into one in the middle of the hollow fiber bundle in which the space between fibers is uniform in distance. Since the hollow fiber membrane pervaporation system is the first one ever developed in the world, our own unique proprietary technology can be secured, preoccupying technical superiority in export competitive challenges.

• Membrane Journal
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• v.1 no.1
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• pp.78-95
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• 1991

Water factory 21(WF 2) in Orange County California, is a advanced wastewater treatment(AWT) plant designed to reclaim biologically treated munidpal wastewater for injection into a seawater barrier system. Processes included are lime treatment air stripping, filtration, activated carbon adsorption, reverse osmosis(RO), and chlorination. The effectiveness of each treatment process is presented including pretreatment, RO dimineralization. The data collected show that the processes, including RO, used at WF-21 are capable of producing a very high quality water on a reliable basis. Treatment reduced all contaminants, to levels below national primary drinldng water regulation maximum contaminant levels. It was found that lime clarified secondary effluent can be used as feedwater to a RO dimineralizer. Experiments with new low pressure membrane(250psi) show great potential for reducing RO cost.

• Korean Membrane Journal
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• v.10 no.1
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• pp.13-19
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• 2008

Water softening is a very promising field for membranes and especially ultra low pressure membranes. Nanofiltration membranes based on pore-filling technology was prepared by using a new technique: the in-situ cross-linking. This route involves introducing a pre-formed polymer into the pores of a host membrane and then locking the polymer in the pores by in-situ cross-linking with an appropriate reagent. By this way, it is possible to make robust and competitive, pore-filled, anion-exchange membranes with excellent control over the properties of the incorporated gel without affecting the host membrane. In this paper, the possibilities of tuning such membranes for ultra low pressure water softening was examined by altering pore-filling chemistry (by changing cross-linking and aminating reagents). The results showed that tuning the chemistry of the pore-filling has important effects. In particularly, it had been shown that the correct selection of cross-linking reagent was not only essential to get pore-filled membranes but it could control their properties. Moreover, the aminating reagent could improve membrane performance. It was found that an increase in hydrophobicity could improve the Darcy permeability.

• Membrane and Water Treatment
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• v.3 no.4
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• pp.221-230
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• 2012

This study employed the modified fouling index (MFI) to determine the performance of a two-step recycling system - a membrane filtration integrated laminar flow water storage (LFWS) tank followed by an ion exchange process to reclaim ultrapure water (UPW) from the wastewater generated from semiconductor wafer backgrinding and sawing processes. The first step consisted of the utilization of either ultrafiltration (UF) or nanofiltration (NF) membranes to remove solids in the wastewater where the second step consisted of an ion exchanger to further purify the filtrate. The system was able to produce high purity water in a continuous operating mode. However, higher recycling cost could be incurred due to membrane fouling. The feed wastewater used for this study contained high concentration of fine particles with low organic and ionic contents, hence membrane fouling was mainly attributed to particulate deposition and cake formation. Based on the MFI results, a LFWS tank that was equipped with a turbulence reducer with a pair of auto-valves was developed and found effective in minimizing fouling by discharging concentrated wastewater prior to any membrane filtration. By comparing flux behaviors of the improved system with the conventional system, the former maintained a high flux than the latter at the end of the experiment.